hibernate根据条件动态组装sql/hql语句(仿ibatis动态查询语句功能)
2016-06-23 11:49
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1.功能需求背景
项目中使用hibernate作为数据持久层框架，主要考虑hibernate在进行一些简单的crud操作时非常便利，不需要和ibatis似的为每个sql操作都写一堆文件，但是同时也带来了一些局限性，如类似ibatis强大的动态查询功能用不了了，但是这个功能在项目中的应用场景又很大，hibernate自身也支持将sql/hql语句写在.hbm.xml映射文件中<sql-query>和<query>元素，但是这个功能只能对那些查询限制条件固定的sql有用，对于需要动态拼接的sql语句，hibernate就显得力不从心了，如何给hibernate插上ibatis动态查询的翅膀，既保留crud的简洁性，又能收获ibatis的特性呢？接下来的文章将会重点介绍
2.设计思路
先看一下ibatis的动态查询时怎么做的
<select id="getUserList" resultMap="user">
select * from user
<isGreaterThan prepend="and" property="id" compareValue="0">
where user_id = #userId#
</isGreaterThan>
order by createTime desc
</select>
ibatis在程序实现内部回去解析sql语句中的标签，然后去解析计算，我们在ibatis在实现的时候也参考了这个解决思路，但是否是需要把ibatis里的解析sql的语法都抄到我们的dao框架中呢-显然这样太复杂了，而且ibatis自己的sql元素是和那些resultMap等是绑定在一起用的，而在hibernate是没用这些东西的，要改造这些东西是一项非常浩大的工程，因此这个方案被放弃了
我们在实现的时候采取了一种非常简洁又功能强大的方式-模板技术!对，就是利用freemarker把sql/hql中的动态拼接条件判断语法都交给freemarker语法去处理，这样既能复用freemarker框架，又保持了我们框架设计的简洁性-不需要自己写过多的处理逻辑,以下是我们需要进行动态处理的sql/hql语句的样例
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<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE dynamic-hibernate-statement PUBLIC "-//Haier/HOP Hibernate Dynamic Statement DTD 1.0//EN"
"http://www.haier.com/dtd/dynamic-hibernate-statement-1.0.dtd">
<dynamic-hibernate-statement>
<!-- 查询某个资源下的直接子节点 -->
<hql-query name="resource.getChildren">
<![CDATA[
from Resource where parent.id=${parentId} and parent.id != id
]]>
</hql-query>
<!-- 查询系统中所有的root资源 -->
<hql-query name="resource.getRoots">
<![CDATA[
from Resource where parent.id = id order by orderIndex
]]>
</hql-query>
<!-- 获取某个用户可访问的某个资源下的所有子资源 -->
<sql-query name="resource.getDescendants">
<![CDATA[
select distinct t.id,
t.name,
t.description,
t.url,
t.type,
t.status,
t.code,
t.configuration,
t.module_name,
t.gmt_create,
t.gmt_modified,
t.create_by,
t.last_modified_by,
t.order_index,
t.parent_id
from resource_info t
inner join role_resource rr
on t.id = rr.resource_id
inner join user_role ur
on rr.role_id = ur.role_id
where ur.user_id = ${userId}
<#if type == '1'>
and t.type=1
<#else>
and t.type=0
</#if>
and t.type = ${type}
and t.status = ${status}
start with t.code = '${code}'
connect by nocycle prior t.id = t.parent_id
]]>
</sql-query>
</dynamic-hibernate-statement>
这个文件看起来非常类似ibatis的语句了，只是没用ibatis的哪些标签-改成了freemarker语法，没错，我们就是复用freemarker来帮我们解决这些烦杂的判断操作的
这样我们的动态sql程序就可以总结成以下流程
a.系统加载阶段
这个阶段程序负责将指定路径下的动态sql文件加载到内存中，一次性缓存起来，没错，这些东西只需要加载一次，以后直接读取就行了，没必要每次去查找，缓存也非常简单，一个Map<String,String>就搞定，key是sql-query或hql-query元素的name属性，value就是与其对应的sql/hql语句
b.程序调用查询阶段
调用程序通过sql/hql语句的name属性和传入查询参数来得到最终解析出来的语句
我们期望的方法可能是这样的：
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public <X> List<X> findByNamedQuery(final String queryName, final Map<String, ?> parameters)
通过queryName从缓存中查找出其对应的sql/hql语句(最原始的，里面带有freemarker语法)
然后通过freemarker模板和传递进去的parameters参数对模板进行解析，得到最终的语句(纯sql/hql)
最后将解析后的sql/hql传递给底层api，返回查询结果
3.实现
上面介绍了大致的思路，这里介绍具体的代码实现
3.1DTD定义
我们是把动态的sql/hql语句放在单独的xml配置文件里的，为了规范xml文档，我们给文档定义了dtd文件，这里我们只定义了两个元素<sql-query>和<hql-query>分别表示sql查询语句和hql查询语句，这两个元素目前自有一个name属性用来唯一标示该语句，如下
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<!-- HOP Hibernate Dynamic Statement Mapping DTD.
<!DOCTYPE dynamic-hibernate-statement PUBLIC
"-//Haier/HOP Hibernate Dynamic Statement DTD 1.0//EN"
"http://www.haier.com/dtd/dynamic-hibernate-statement-1.0.dtd">
这个文件时用来定义动态参数语句，类似itabis
-->
<!--
The document root.
-->
<!ELEMENT dynamic-hibernate-statement (
(hql-query|sql-query)*
)>
<!-- default: none -->
<!-- The query element declares a named Hibernate query string -->
<!ELEMENT hql-query (#PCDATA)>
<!ATTLIST hql-query name CDATA #REQUIRED>
<!-- The sql-query element declares a named SQL query string -->
<!ELEMENT sql-query (#PCDATA)>
<!ATTLIST sql-query name CDATA #REQUIRED>
然后将其保存为dynamic-hibernate-statement-1.0.dtd，放在classpath下
编写DTD校验器
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/**
* hibernate动态sql dtd解析器
* @author WangXuzheng
*
*/
public class DynamicStatementDTDEntityResolver implements EntityResolver, Serializable{
private static final long serialVersionUID = 8123799007554762965L;
private static final Logger LOGGER = LoggerFactory.getLogger( DynamicStatementDTDEntityResolver.class );
private static final String HOP_DYNAMIC_STATEMENT = "http://www.haier.com/dtd/";
public InputSource resolveEntity(String publicId, String systemId) {
InputSource source = null; // returning null triggers default behavior
if ( systemId != null ) {
LOGGER.debug( "trying to resolve system-id [" + systemId + "]" );
if ( systemId.startsWith( HOP_DYNAMIC_STATEMENT ) ) {
LOGGER.debug( "recognized hop dyanmic statement namespace; attempting to resolve on classpath under com/haier/openplatform/dao/hibernate/" );
source = resolveOnClassPath( publicId, systemId, HOP_DYNAMIC_STATEMENT );
}
}
return source;
}
private InputSource resolveOnClassPath(String publicId, String systemId, String namespace) {
InputSource source = null;
String path = "com/haier/openplatform/dao/hibernate/" + systemId.substring( namespace.length() );
InputStream dtdStream = resolveInHibernateNamespace( path );
if ( dtdStream == null ) {
LOGGER.debug( "unable to locate [" + systemId + "] on classpath" );
if ( systemId.substring( namespace.length() ).indexOf( "2.0" ) > -1 ) {
LOGGER.error( "Don't use old DTDs, read the Hibernate 3.x Migration Guide!" );
}
}
else {
LOGGER.debug( "located [" + systemId + "] in classpath" );
source = new InputSource( dtdStream );
source.setPublicId( publicId );
source.setSystemId( systemId );
}
return source;
}
protected InputStream resolveInHibernateNamespace(String path) {
return this.getClass().getClassLoader().getResourceAsStream( path );
}
protected InputStream resolveInLocalNamespace(String path) {
try {
return ConfigHelper.getUserResourceAsStream( path );
}
catch ( Throwable t ) {
return null;
}
}
}
3.2编写sql文件
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<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE dynamic-hibernate-statement PUBLIC "-//Haier/HOP Hibernate Dynamic Statement DTD 1.0//EN"
"http://www.haier.com/dtd/dynamic-hibernate-statement-1.0.dtd">
<dynamic-hibernate-statement>
<!-- 查询某个资源下的直接子节点 -->
<hql-query name="resource.getChildren">
<![CDATA[
from Resource where parent.id=${parentId} and parent.id != id
]]>
</hql-query>
<!-- 查询系统中所有的root资源 -->
<hql-query name="resource.getRoots">
<![CDATA[
from Resource where parent.id = id order by orderIndex
]]>
</hql-query>
<!-- 获取某个用户可访问的某个资源下的所有子资源 -->
<sql-query name="resource.getDescendants">
<![CDATA[
select distinct t.id,
t.name,
t.description,
t.url,
t.type,
t.status,
t.code,
t.configuration,
t.module_name,
t.gmt_create,
t.gmt_modified,
t.create_by,
t.last_modified_by,
t.order_index,
t.parent_id
from resource_info t
inner join role_resource rr
on t.id = rr.resource_id
inner join user_role ur
on rr.role_id = ur.role_id
where ur.user_id = ${userId}
<#if type == '1'>
and t.type=1
<#else>
and t.type=0
</#if>
and t.type = ${type}
and t.status = ${status}
start with t.code = '${code}'
connect by nocycle prior t.id = t.parent_id
]]>
</sql-query>
</dynamic-hibernate-statement>
3.3加载动态sql文件
这里我们将加载sql/hql语句的程序独立到一个单独的类中，以便独立扩展
这里一共3个方法，分表标示获取系统中sql/hql语句的map(key:语句名称,value:具体的)
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/**
* 动态sql/hql语句组装器
* @author WangXuzheng
*
*/
public interface DynamicHibernateStatementBuilder {
/**
* hql语句map
* @return
*/
public Map<String,String> getNamedHQLQueries();
/**
* sql语句map
* @return
*/
public Map<String,String> getNamedSQLQueries();
/**
* 初始化
* @throws IOException
*/
public void init() throws IOException;
}
默认的加载器-将指定配置文件中的sql/hql语句加载到内存中
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/**
* @author WangXuzheng
*
*/
public class DefaultDynamicHibernateStatementBuilder implements DynamicHibernateStatementBuilder, ResourceLoaderAware {
private static final Logger LOGGER = LoggerFactory.getLogger(DefaultDynamicHibernateStatementBuilder.class);
private Map<String, String> namedHQLQueries;
private Map<String, String> namedSQLQueries;
private String[] fileNames = new String[0];
private ResourceLoader resourceLoader;
private EntityResolver entityResolver = new DynamicStatementDTDEntityResolver();
/**
* 查询语句名称缓存，不允许重复
*/
private Set<String> nameCache = new HashSet<String>();
public void setFileNames(String[] fileNames) {
this.fileNames = fileNames;
}
@Override
public Map<String, String> getNamedHQLQueries() {
return namedHQLQueries;
}
@Override
public Map<String, String> getNamedSQLQueries() {
return namedSQLQueries;
}
@Override
public void init() throws IOException {
namedHQLQueries = new HashMap<String, String>();
namedSQLQueries = new HashMap<String, String>();
boolean flag = this.resourceLoader instanceof ResourcePatternResolver;
for (String file : fileNames) {
if (flag) {
Resource[] resources = ((ResourcePatternResolver) this.resourceLoader).getResources(file);
buildMap(resources);
} else {
Resource resource = resourceLoader.getResource(file);
buildMap(resource);
}
}
//clear name cache
nameCache.clear();
}
@Override
public void setResourceLoader(ResourceLoader resourceLoader) {
this.resourceLoader = resourceLoader;
}
private void buildMap(Resource[] resources) throws IOException {
if (resources == null) {
return;
}
for (Resource resource : resources) {
buildMap(resource);
}
}
@SuppressWarnings({ "rawtypes" })
private void buildMap(Resource resource) {
InputSource inputSource = null;
try {
inputSource = new InputSource(resource.getInputStream());
XmlDocument metadataXml = MappingReader.INSTANCE.readMappingDocument(entityResolver, inputSource,
new OriginImpl("file", resource.getFilename()));
if (isDynamicStatementXml(metadataXml)) {
final Document doc = metadataXml.getDocumentTree();
final Element dynamicHibernateStatement = doc.getRootElement();
Iterator rootChildren = dynamicHibernateStatement.elementIterator();
while (rootChildren.hasNext()) {
final Element element = (Element) rootChildren.next();
final String elementName = element.getName();
if ("sql-query".equals(elementName)) {
putStatementToCacheMap(resource, element, namedSQLQueries);
} else if ("hql-query".equals(elementName)) {
putStatementToCacheMap(resource, element, namedHQLQueries);
}
}
}
} catch (Exception e) {
LOGGER.error(e.toString());
throw new SysException(e);
} finally {
if (inputSource != null && inputSource.getByteStream() != null) {
try {
inputSource.getByteStream().close();
} catch (IOException e) {
LOGGER.error(e.toString());
throw new SysException(e);
}
}
}
}
private void putStatementToCacheMap(Resource resource, final Element element, Map<String, String> statementMap)
throws IOException {
String sqlQueryName = element.attribute("name").getText();
Validate.notEmpty(sqlQueryName);
if (nameCache.contains(sqlQueryName)) {
throw new SysException("重复的sql-query/hql-query语句定义在文件:" + resource.getURI() + "中，必须保证name的唯一.");
}
nameCache.add(sqlQueryName);
String queryText = element.getText();
statementMap.put(sqlQueryName, queryText);
}
private static boolean isDynamicStatementXml(XmlDocument xmlDocument) {
return "dynamic-hibernate-statement".equals(xmlDocument.getDocumentTree().getRootElement().getName());
}
}
配置一下
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<bean id="dynamicStatementBuilder" class="com.haier.openplatform.dao.hibernate.support.DefaultDynamicHibernateStatementBuilder">
<property name="fileNames">
<list>
<value>classpath*:/**/*-dynamic.xml</value><!--这里我们指定要加载某个文件夹下所有以-dynamic.xml结尾的文件 -->
</list>
</property>
</bean>
<bean id="baseHibernateDAO" class="com.haier.openplatform.dao.hibernate.BaseDAOHibernateImpl" abstract="true">
<property name="sessionFactory">
<ref bean="sessionFactory"/>
</property>
<property name="dynamicStatementBuilder" ref="dynamicStatementBuilder"/>
</bean>
dao层代码
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/**
* Hibernate实现的DAO层
* @param <T> DAO操作的对象类型
* @param <ID> 主键类型
* @author WangXuzheng
*
*/
public class SimpleHibernateDAO<T,ID extends Serializable> implements BaseDAO<T, ID>,InitializingBean{
private static final Logger LOGER = LoggerFactory.getLogger(SimpleHibernateDAO.class);
protected SessionFactory sessionFactory;
protected Class<T> entityClass;
/**
* 模板缓存
*/
protected Map<String, StatementTemplate> templateCache;
protected DynamicHibernateStatementBuilder dynamicStatementBuilder;
/**
* 通过子类的泛型定义取得对象类型Class.
* eg.
* public class UserDao extends SimpleHibernateDao<User, Long>
*/
public SimpleHibernateDAO() {
this.entityClass = Reflections.getSuperClassGenricType(getClass());
}
/**
* 取得sessionFactory.
*/
public SessionFactory getSessionFactory() {
return sessionFactory;
}
/**
* 采用@Autowired按类型注入SessionFactory, 当有多个SesionFactory的时候在子类重载本函数.
*/
public void setSessionFactory(final SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
public void setDynamicStatementBuilder(DynamicHibernateStatementBuilder dynamicStatementBuilder) {
this.dynamicStatementBuilder = dynamicStatementBuilder;
}
/**
* 取得当前Session.
*/
public Session getSession() {
return sessionFactory.getCurrentSession();
}
/**
* 保存新增或修改的对象.
*/
@Override
public void save(final T entity) {
Validate.notNull(entity, "entity不能为空");
getSession().save(entity);
LOGER.debug("save entity: {}", entity);
}
/**
* 删除对象.
*
* @param entity 对象必须是session中的对象或含id属性的transient对象.
*/
@Override
public void delete(final T entity) {
if(entity == null){
return;
}
getSession().delete(entity);
LOGER.debug("delete entity: {}", entity);
}
/**
* 按id删除对象.
*/
@Override
public void delete(final ID id) {
Validate.notNull(id, "id不能为空");
delete(get(id));
LOGER.debug("delete entity {},id is {}", entityClass.getSimpleName(), id);
}
/**
* 按id获取对象.
*/
@SuppressWarnings("unchecked")
@Override
public T get(final ID id) {
Validate.notNull(id, "id不能为空");
return (T) getSession().get(entityClass, id);
}
/**
* 按id列表获取对象列表.
*/
public List<T> get(final Collection<ID> ids) {
return find(Restrictions.in(getIdName(), ids));
}
/**
* 获取全部对象.
*/
@Override
public List<T> getAll() {
return find();
}
/**
* 获取全部对象, 支持按属性行序.
*/
@SuppressWarnings("unchecked")
public List<T> getAll(String orderByProperty, boolean isAsc) {
Criteria c = createCriteria();
if (isAsc) {
c.addOrder(Order.asc(orderByProperty));
} else {
c.addOrder(Order.desc(orderByProperty));
}
return c.list();
}
/**
* 按属性查找对象列表, 匹配方式为相等.
*/
public List<T> findBy(final String propertyName, final Object value) {
Criterion criterion = Restrictions.eq(propertyName, value);
return find(criterion);
}
/**
* 按属性查找唯一对象, 匹配方式为相等.
*/
@SuppressWarnings("unchecked")
@Override
public T findUniqueBy(final String propertyName, final Object value) {
Criterion criterion = Restrictions.eq(propertyName, value);
return ((T) createCriteria(criterion).uniqueResult());
}
/**
* 按HQL查询对象列表.
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findByHQL(final String hql, final Object... values) {
return createHQLQuery(hql, values).list();
}
/**
* 按HQL查询对象列表，并将对象封装成指定的对象
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findByHQLRowMapper(RowMapper<X> rowMapper,final String hql, final Object... values) {
Validate.notNull(rowMapper, "rowMapper不能为空！");
List<Object[]> result = createHQLQuery(hql, values).list();
return buildListResultFromRowMapper(rowMapper, result);
}
protected <X> List<X> buildListResultFromRowMapper(RowMapper<X> rowMapper, List<Object[]> result) {
List<X> rs = new ArrayList<X>(result.size());
for(Object[] obj : result){
rs.add(rowMapper.fromColumn(obj));
}
return rs;
}
/**
* 按SQL查询对象列表.
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findBySQLRowMapper(RowMapper<X> rowMapper,final String sql, final Object... values) {
Validate.notNull(rowMapper, "rowMapper不能为空！");
List<Object[]> result = createSQLQuery(sql, values).list();
return buildListResultFromRowMapper(rowMapper, result);
}
/**
* 按SQL查询对象列表,并将结果集转换成指定的对象列表
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findBySQL(final String sql, final Object... values) {
return createSQLQuery(sql, values).list();
}
/**
* 按HQL查询对象列表.
*
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findByHQL(final String hql, final Map<String, ?> values) {
return createHQLQuery(hql, values).list();
}
/**
* 按HQL查询对象列表,并将结果集封装成对象列表
*
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findByHQLRowMapper(RowMapper<X> rowMapper,final String hql, final Map<String, ?> values) {
Validate.notNull(rowMapper, "rowMapper不能为空！");
List<Object[]> result = createHQLQuery(hql, values).list();
return buildListResultFromRowMapper(rowMapper, result);
}
/**
* 按SQL查询对象列表.
* @param sql SQL查询语句
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findBySQL(final String sql, final Map<String, ?> values) {
return createSQLQuery(sql, values).list();
}
/**
* 查询在xxx.hbm.xml中配置的查询语句
* @param queryName 查询的名称
* @param parameters 参数
* @return
*/
public <X> List<X> findByNamedQuery(final String queryName, final Map<String, ?> parameters) {
StatementTemplate statementTemplate = templateCache.get(queryName);
String statement = processTemplate(statementTemplate,parameters);
if(statementTemplate.getType() == StatementTemplate.TYPE.HQL){
return this.findByHQL(statement);
}else{
return this.findBySQL(statement);
}
}
/**
* 查询在xxx.hbm.xml中配置的查询语句
* @param rowMapper
* @param queryName 查询的名称
* @param parameters 参数
* @return
*/
public <X> List<X> findByNamedQuery(RowMapper<X> rowMapper,final String queryName, final Map<String, ?> parameters) {
StatementTemplate statementTemplate = templateCache.get(queryName);
String statement = processTemplate(statementTemplate,parameters);
if(statementTemplate.getType() == StatementTemplate.TYPE.HQL){
return this.findByHQLRowMapper(rowMapper,statement);
}else{
return this.findBySQLRowMapper(rowMapper,statement);
}
}
/**
* 按SQL查询对象列表,并将结果集封装成对象列表
* @param sql SQL查询语句
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findBySQLRowMapper(RowMapper<X> rowMapper,final String sql, final Map<String, ?> values) {
Validate.notNull(rowMapper, "rowMapper不能为空！");
List<Object[]> result = createSQLQuery(sql, values).list();
return buildListResultFromRowMapper(rowMapper, result);
}
/**
* 按HQL查询唯一对象.
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> X findUniqueByHQL(final String hql, final Object... values) {
return (X) createHQLQuery(hql, values).uniqueResult();
}
/**
* 按SQL查询唯一对象.
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> X findUniqueBySQL(final String sql, final Object... values) {
return (X) createSQLQuery(sql, values).uniqueResult();
}
/**
* 按HQL查询唯一对象.
*
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> X findUniqueByHQL(final String hql, final Map<String, ?> values) {
return (X) createHQLQuery(hql, values).uniqueResult();
}
/**
* 按HQL查询唯一对象.
* @param sql sql语句
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> X findUniqueBySQL(final String sql, final Map<String, ?> values) {
return (X) createSQLQuery(sql, values).uniqueResult();
}
/**
* 执行HQL进行批量修改/删除操作.
*
* @param values 数量可变的参数,按顺序绑定.
* @return 更新记录数.
*/
public int batchExecuteHQL(final String hql, final Object... values) {
return createHQLQuery(hql, values).executeUpdate();
}
/**
* 执行SQL进行批量修改/删除操作.
*
* @param sql sql语句
* @param values 数量可变的参数,按顺序绑定.
* @return 更新记录数.
*/
public int batchExecuteSQL(final String sql, final Object... values) {
return createSQLQuery(sql, values).executeUpdate();
}
/**
* 执行HQL进行批量修改/删除操作.
*
* @param values 命名参数,按名称绑定.
* @return 更新记录数.
*/
public int batchExecuteHQL(final String hql, final Map<String, ?> values) {
return createHQLQuery(hql, values).executeUpdate();
}
/**
* 执行SQL进行批量修改/删除操作.
*
* @param values 命名参数,按名称绑定.
* @return 更新记录数.
*/
public int batchExecuteSQL(final String sql, final Map<String, ?> values) {
return createSQLQuery(sql, values).executeUpdate();
}
/**
* 根据查询HQL与参数列表创建Query对象.
* 与find()函数可进行更加灵活的操作.
*
* @param values 数量可变的参数,按顺序绑定.
*/
public Query createHQLQuery(final String queryString, final Object... values) {
Query query = getSession().createQuery(queryString);
if (values != null) {
for (int i = 0; i < values.length; i++) {
query.setParameter(i, values[i]);
}
}
return query;
}
/**
* 根据查询SQL与参数列表创建Query对象.
* 与find()函数可进行更加灵活的操作.
* @param sqlQueryString sql语句
*
* @param values 数量可变的参数,按顺序绑定.
*/
public Query createSQLQuery(final String sqlQueryString, final Object... values) {
Query query = getSession().createSQLQuery(sqlQueryString);
if (values != null) {
for (int i = 0; i < values.length; i++) {
query.setParameter(i, values[i]);
}
}
return query;
}
/**
* 根据查询HQL与参数列表创建Query对象.
* 与find()函数可进行更加灵活的操作.
*
* @param values 命名参数,按名称绑定.
*/
public Query createHQLQuery(final String queryString, final Map<String, ?> values) {
Query query = getSession().createQuery(queryString);
if (values != null) {
query.setProperties(values);
}
return query;
}
/**
* 根据查询SQL与参数列表创建Query对象.
* 与find()函数可进行更加灵活的操作.
* @param queryString SQL语句
* @param values 命名参数,按名称绑定.
*/
public Query createSQLQuery(final String queryString, final Map<String, ?> values) {
Query query = getSession().createSQLQuery(queryString);
if (values != null) {
query.setProperties(values);
}
return query;
}
/**
* 按Criteria查询对象列表.
*
* @param criterions 数量可变的Criterion.
*/
@SuppressWarnings("unchecked")
public List<T> find(final Criterion... criterions) {
return createCriteria(criterions).list();
}
/**
* 按Criteria查询唯一对象.
*
* @param criterions 数量可变的Criterion.
*/
@SuppressWarnings("unchecked")
public T findUnique(final Criterion... criterions) {
return (T) createCriteria(criterions).uniqueResult();
}
/**
* 根据Criterion条件创建Criteria.
* 与find()函数可进行更加灵活的操作.
*
* @param criterions 数量可变的Criterion.
*/
public Criteria createCriteria(final Criterion... criterions) {
Criteria criteria = getSession().createCriteria(entityClass);
for (Criterion c : criterions) {
criteria.add(c);
}
return criteria;
}
/**
* 初始化对象.
* 使用load()方法得到的仅是对象Proxy, 在传到View层前需要进行初始化.
* 如果传入entity, 则只初始化entity的直接属性,但不会初始化延迟加载的关联集合和属性.
* 如需初始化关联属性,需执行:
* Hibernate.initialize(user.getRoles())，初始化User的直接属性和关联集合.
* Hibernate.initialize(user.getDescription())，初始化User的直接属性和延迟加载的Description属性.
*/
public void initProxyObject(Object proxy) {
Hibernate.initialize(proxy);
}
/**
* Flush当前Session.
*/
public void flush() {
getSession().flush();
}
/**
* 为Query添加distinct transformer.
* 预加载关联对象的HQL会引起主对象重复, 需要进行distinct处理.
*/
public Query distinct(Query query) {
query.setResultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY);
return query;
}
/**
* 为Criteria添加distinct transformer.
* 预加载关联对象的HQL会引起主对象重复, 需要进行distinct处理.
*/
public Criteria distinct(Criteria criteria) {
criteria.setResultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY);
return criteria;
}
/**
* 取得对象的主键名.
*/
public String getIdName() {
ClassMetadata meta = getSessionFactory().getClassMetadata(entityClass);
return meta.getIdentifierPropertyName();
}
/**
* 判断对象的属性值在数据库内是否唯一.
*
* 在修改对象的情景下,如果属性新修改的值(value)等于属性原来的值(orgValue)则不作比较.
*/
public boolean isPropertyUnique(final String propertyName, final Object newValue, final Object oldValue) {
if (newValue == null || newValue.equals(oldValue)) {
return true;
}
Object object = findUniqueBy(propertyName, newValue);
return (object == null);
}
@Override
public void update(T object) {
getSession().update(object);
}
@SuppressWarnings("unchecked")
@Override
public T load(ID id) {
return (T) getSession().load(this.entityClass, id);
}
/**
* 将list转化为数组
* @param list
* @return
*/
protected Criterion[] list2Array(List<Criterion> list){
if(list == null){
return new Criterion[0];
}
Criterion[] result = new Criterion[list.size()];
for(int i = 0; i < list.size(); i++){
result[i] = list.get(i);
}
return result;
}
@Override
public void afterPropertiesSet() throws Exception {
templateCache = new HashMap<String, StatementTemplate>();
if(this.dynamicStatementBuilder == null){
this.dynamicStatementBuilder = new NoneDynamicHibernateStatementBuilder();
}
dynamicStatementBuilder.init();
Map<String,String> namedHQLQueries = dynamicStatementBuilder.getNamedHQLQueries();
Map<String,String> namedSQLQueries = dynamicStatementBuilder.getNamedSQLQueries();
Configuration configuration = new Configuration();
configuration.setNumberFormat("#");
StringTemplateLoader stringLoader = new StringTemplateLoader();
for(Entry<String, String> entry : namedHQLQueries.entrySet()){
stringLoader.putTemplate(entry.getKey(), entry.getValue());
templateCache.put(entry.getKey(), new StatementTemplate(StatementTemplate.TYPE.HQL,new Template(entry.getKey(),new StringReader(entry.getValue()),configuration)));
}
for(Entry<String, String> entry : namedSQLQueries.entrySet()){
stringLoader.putTemplate(entry.getKey(), entry.getValue());
templateCache.put(entry.getKey(), new StatementTemplate(StatementTemplate.TYPE.SQL,new Template(entry.getKey(),new StringReader(entry.getValue()),configuration)));
}
configuration.setTemplateLoader(stringLoader);
}
protected String processTemplate(StatementTemplate statementTemplate,Map<String, ?> parameters){
StringWriter stringWriter = new StringWriter();
try {
statementTemplate.getTemplate().process(parameters, stringWriter);
} catch (Exception e) {
LOGER.error("处理DAO查询参数模板时发生错误：{}",e.toString());
throw new SysException(e);
}
return stringWriter.toString();
}
}
我们的SimpleHibernateDAO实现了InitializingBean,在其afterProperties方法中我们将调用DynamicHibernateStatementBuilder把语句缓存起来
上层方法调用示例-这个已经非常类似ibatis了
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public List<Resource> getDescendants(Long userId,String code) {
Map<String, Object> values = new HashMap<String, Object>();
values.put("userId", String.valueOf(userId));
values.put("code", code);
values.put("type", String.valueOf(ResourceTypeEnum.URL_RESOURCE.getType()));
values.put("status", String.valueOf(ResourceStatusEnum.ACTIVE.getStatus()));
return this.findByNamedQuery(new ResourceRowMapper(),"resource.getDescendants", values);
}
项目中使用hibernate作为数据持久层框架，主要考虑hibernate在进行一些简单的crud操作时非常便利，不需要和ibatis似的为每个sql操作都写一堆文件，但是同时也带来了一些局限性，如类似ibatis强大的动态查询功能用不了了，但是这个功能在项目中的应用场景又很大，hibernate自身也支持将sql/hql语句写在.hbm.xml映射文件中<sql-query>和<query>元素，但是这个功能只能对那些查询限制条件固定的sql有用，对于需要动态拼接的sql语句，hibernate就显得力不从心了，如何给hibernate插上ibatis动态查询的翅膀，既保留crud的简洁性，又能收获ibatis的特性呢？接下来的文章将会重点介绍
2.设计思路
先看一下ibatis的动态查询时怎么做的
<select id="getUserList" resultMap="user">
select * from user
<isGreaterThan prepend="and" property="id" compareValue="0">
where user_id = #userId#
</isGreaterThan>
order by createTime desc
</select>
ibatis在程序实现内部回去解析sql语句中的标签，然后去解析计算，我们在ibatis在实现的时候也参考了这个解决思路，但是否是需要把ibatis里的解析sql的语法都抄到我们的dao框架中呢-显然这样太复杂了，而且ibatis自己的sql元素是和那些resultMap等是绑定在一起用的，而在hibernate是没用这些东西的，要改造这些东西是一项非常浩大的工程，因此这个方案被放弃了
我们在实现的时候采取了一种非常简洁又功能强大的方式-模板技术!对，就是利用freemarker把sql/hql中的动态拼接条件判断语法都交给freemarker语法去处理，这样既能复用freemarker框架，又保持了我们框架设计的简洁性-不需要自己写过多的处理逻辑,以下是我们需要进行动态处理的sql/hql语句的样例
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<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE dynamic-hibernate-statement PUBLIC "-//Haier/HOP Hibernate Dynamic Statement DTD 1.0//EN"
"http://www.haier.com/dtd/dynamic-hibernate-statement-1.0.dtd">
<dynamic-hibernate-statement>
<!-- 查询某个资源下的直接子节点 -->
<hql-query name="resource.getChildren">
<![CDATA[
from Resource where parent.id=${parentId} and parent.id != id
]]>
</hql-query>
<!-- 查询系统中所有的root资源 -->
<hql-query name="resource.getRoots">
<![CDATA[
from Resource where parent.id = id order by orderIndex
]]>
</hql-query>
<!-- 获取某个用户可访问的某个资源下的所有子资源 -->
<sql-query name="resource.getDescendants">
<![CDATA[
select distinct t.id,
t.name,
t.description,
t.url,
t.type,
t.status,
t.code,
t.configuration,
t.module_name,
t.gmt_create,
t.gmt_modified,
t.create_by,
t.last_modified_by,
t.order_index,
t.parent_id
from resource_info t
inner join role_resource rr
on t.id = rr.resource_id
inner join user_role ur
on rr.role_id = ur.role_id
where ur.user_id = ${userId}
<#if type == '1'>
and t.type=1
<#else>
and t.type=0
</#if>
and t.type = ${type}
and t.status = ${status}
start with t.code = '${code}'
connect by nocycle prior t.id = t.parent_id
]]>
</sql-query>
</dynamic-hibernate-statement>
这个文件看起来非常类似ibatis的语句了，只是没用ibatis的哪些标签-改成了freemarker语法，没错，我们就是复用freemarker来帮我们解决这些烦杂的判断操作的
这样我们的动态sql程序就可以总结成以下流程
a.系统加载阶段
这个阶段程序负责将指定路径下的动态sql文件加载到内存中，一次性缓存起来，没错，这些东西只需要加载一次，以后直接读取就行了，没必要每次去查找，缓存也非常简单，一个Map<String,String>就搞定，key是sql-query或hql-query元素的name属性，value就是与其对应的sql/hql语句
b.程序调用查询阶段
调用程序通过sql/hql语句的name属性和传入查询参数来得到最终解析出来的语句
我们期望的方法可能是这样的：
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public <X> List<X> findByNamedQuery(final String queryName, final Map<String, ?> parameters)
通过queryName从缓存中查找出其对应的sql/hql语句(最原始的，里面带有freemarker语法)
然后通过freemarker模板和传递进去的parameters参数对模板进行解析，得到最终的语句(纯sql/hql)
最后将解析后的sql/hql传递给底层api，返回查询结果
3.实现
上面介绍了大致的思路，这里介绍具体的代码实现
3.1DTD定义
我们是把动态的sql/hql语句放在单独的xml配置文件里的，为了规范xml文档，我们给文档定义了dtd文件，这里我们只定义了两个元素<sql-query>和<hql-query>分别表示sql查询语句和hql查询语句，这两个元素目前自有一个name属性用来唯一标示该语句，如下
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<!-- HOP Hibernate Dynamic Statement Mapping DTD.
<!DOCTYPE dynamic-hibernate-statement PUBLIC
"-//Haier/HOP Hibernate Dynamic Statement DTD 1.0//EN"
"http://www.haier.com/dtd/dynamic-hibernate-statement-1.0.dtd">
这个文件时用来定义动态参数语句，类似itabis
-->
<!--
The document root.
-->
<!ELEMENT dynamic-hibernate-statement (
(hql-query|sql-query)*
)>
<!-- default: none -->
<!-- The query element declares a named Hibernate query string -->
<!ELEMENT hql-query (#PCDATA)>
<!ATTLIST hql-query name CDATA #REQUIRED>
<!-- The sql-query element declares a named SQL query string -->
<!ELEMENT sql-query (#PCDATA)>
<!ATTLIST sql-query name CDATA #REQUIRED>
然后将其保存为dynamic-hibernate-statement-1.0.dtd，放在classpath下
编写DTD校验器
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/**
* hibernate动态sql dtd解析器
* @author WangXuzheng
*
*/
public class DynamicStatementDTDEntityResolver implements EntityResolver, Serializable{
private static final long serialVersionUID = 8123799007554762965L;
private static final Logger LOGGER = LoggerFactory.getLogger( DynamicStatementDTDEntityResolver.class );
private static final String HOP_DYNAMIC_STATEMENT = "http://www.haier.com/dtd/";
public InputSource resolveEntity(String publicId, String systemId) {
InputSource source = null; // returning null triggers default behavior
if ( systemId != null ) {
LOGGER.debug( "trying to resolve system-id [" + systemId + "]" );
if ( systemId.startsWith( HOP_DYNAMIC_STATEMENT ) ) {
LOGGER.debug( "recognized hop dyanmic statement namespace; attempting to resolve on classpath under com/haier/openplatform/dao/hibernate/" );
source = resolveOnClassPath( publicId, systemId, HOP_DYNAMIC_STATEMENT );
}
}
return source;
}
private InputSource resolveOnClassPath(String publicId, String systemId, String namespace) {
InputSource source = null;
String path = "com/haier/openplatform/dao/hibernate/" + systemId.substring( namespace.length() );
InputStream dtdStream = resolveInHibernateNamespace( path );
if ( dtdStream == null ) {
LOGGER.debug( "unable to locate [" + systemId + "] on classpath" );
if ( systemId.substring( namespace.length() ).indexOf( "2.0" ) > -1 ) {
LOGGER.error( "Don't use old DTDs, read the Hibernate 3.x Migration Guide!" );
}
}
else {
LOGGER.debug( "located [" + systemId + "] in classpath" );
source = new InputSource( dtdStream );
source.setPublicId( publicId );
source.setSystemId( systemId );
}
return source;
}
protected InputStream resolveInHibernateNamespace(String path) {
return this.getClass().getClassLoader().getResourceAsStream( path );
}
protected InputStream resolveInLocalNamespace(String path) {
try {
return ConfigHelper.getUserResourceAsStream( path );
}
catch ( Throwable t ) {
return null;
}
}
}
3.2编写sql文件
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<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE dynamic-hibernate-statement PUBLIC "-//Haier/HOP Hibernate Dynamic Statement DTD 1.0//EN"
"http://www.haier.com/dtd/dynamic-hibernate-statement-1.0.dtd">
<dynamic-hibernate-statement>
<!-- 查询某个资源下的直接子节点 -->
<hql-query name="resource.getChildren">
<![CDATA[
from Resource where parent.id=${parentId} and parent.id != id
]]>
</hql-query>
<!-- 查询系统中所有的root资源 -->
<hql-query name="resource.getRoots">
<![CDATA[
from Resource where parent.id = id order by orderIndex
]]>
</hql-query>
<!-- 获取某个用户可访问的某个资源下的所有子资源 -->
<sql-query name="resource.getDescendants">
<![CDATA[
select distinct t.id,
t.name,
t.description,
t.url,
t.type,
t.status,
t.code,
t.configuration,
t.module_name,
t.gmt_create,
t.gmt_modified,
t.create_by,
t.last_modified_by,
t.order_index,
t.parent_id
from resource_info t
inner join role_resource rr
on t.id = rr.resource_id
inner join user_role ur
on rr.role_id = ur.role_id
where ur.user_id = ${userId}
<#if type == '1'>
and t.type=1
<#else>
and t.type=0
</#if>
and t.type = ${type}
and t.status = ${status}
start with t.code = '${code}'
connect by nocycle prior t.id = t.parent_id
]]>
</sql-query>
</dynamic-hibernate-statement>
3.3加载动态sql文件
这里我们将加载sql/hql语句的程序独立到一个单独的类中，以便独立扩展
这里一共3个方法，分表标示获取系统中sql/hql语句的map(key:语句名称,value:具体的)
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/**
* 动态sql/hql语句组装器
* @author WangXuzheng
*
*/
public interface DynamicHibernateStatementBuilder {
/**
* hql语句map
* @return
*/
public Map<String,String> getNamedHQLQueries();
/**
* sql语句map
* @return
*/
public Map<String,String> getNamedSQLQueries();
/**
* 初始化
* @throws IOException
*/
public void init() throws IOException;
}
默认的加载器-将指定配置文件中的sql/hql语句加载到内存中
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/**
* @author WangXuzheng
*
*/
public class DefaultDynamicHibernateStatementBuilder implements DynamicHibernateStatementBuilder, ResourceLoaderAware {
private static final Logger LOGGER = LoggerFactory.getLogger(DefaultDynamicHibernateStatementBuilder.class);
private Map<String, String> namedHQLQueries;
private Map<String, String> namedSQLQueries;
private String[] fileNames = new String[0];
private ResourceLoader resourceLoader;
private EntityResolver entityResolver = new DynamicStatementDTDEntityResolver();
/**
* 查询语句名称缓存，不允许重复
*/
private Set<String> nameCache = new HashSet<String>();
public void setFileNames(String[] fileNames) {
this.fileNames = fileNames;
}
@Override
public Map<String, String> getNamedHQLQueries() {
return namedHQLQueries;
}
@Override
public Map<String, String> getNamedSQLQueries() {
return namedSQLQueries;
}
@Override
public void init() throws IOException {
namedHQLQueries = new HashMap<String, String>();
namedSQLQueries = new HashMap<String, String>();
boolean flag = this.resourceLoader instanceof ResourcePatternResolver;
for (String file : fileNames) {
if (flag) {
Resource[] resources = ((ResourcePatternResolver) this.resourceLoader).getResources(file);
buildMap(resources);
} else {
Resource resource = resourceLoader.getResource(file);
buildMap(resource);
}
}
//clear name cache
nameCache.clear();
}
@Override
public void setResourceLoader(ResourceLoader resourceLoader) {
this.resourceLoader = resourceLoader;
}
private void buildMap(Resource[] resources) throws IOException {
if (resources == null) {
return;
}
for (Resource resource : resources) {
buildMap(resource);
}
}
@SuppressWarnings({ "rawtypes" })
private void buildMap(Resource resource) {
InputSource inputSource = null;
try {
inputSource = new InputSource(resource.getInputStream());
XmlDocument metadataXml = MappingReader.INSTANCE.readMappingDocument(entityResolver, inputSource,
new OriginImpl("file", resource.getFilename()));
if (isDynamicStatementXml(metadataXml)) {
final Document doc = metadataXml.getDocumentTree();
final Element dynamicHibernateStatement = doc.getRootElement();
Iterator rootChildren = dynamicHibernateStatement.elementIterator();
while (rootChildren.hasNext()) {
final Element element = (Element) rootChildren.next();
final String elementName = element.getName();
if ("sql-query".equals(elementName)) {
putStatementToCacheMap(resource, element, namedSQLQueries);
} else if ("hql-query".equals(elementName)) {
putStatementToCacheMap(resource, element, namedHQLQueries);
}
}
}
} catch (Exception e) {
LOGGER.error(e.toString());
throw new SysException(e);
} finally {
if (inputSource != null && inputSource.getByteStream() != null) {
try {
inputSource.getByteStream().close();
} catch (IOException e) {
LOGGER.error(e.toString());
throw new SysException(e);
}
}
}
}
private void putStatementToCacheMap(Resource resource, final Element element, Map<String, String> statementMap)
throws IOException {
String sqlQueryName = element.attribute("name").getText();
Validate.notEmpty(sqlQueryName);
if (nameCache.contains(sqlQueryName)) {
throw new SysException("重复的sql-query/hql-query语句定义在文件:" + resource.getURI() + "中，必须保证name的唯一.");
}
nameCache.add(sqlQueryName);
String queryText = element.getText();
statementMap.put(sqlQueryName, queryText);
}
private static boolean isDynamicStatementXml(XmlDocument xmlDocument) {
return "dynamic-hibernate-statement".equals(xmlDocument.getDocumentTree().getRootElement().getName());
}
}
配置一下
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<bean id="dynamicStatementBuilder" class="com.haier.openplatform.dao.hibernate.support.DefaultDynamicHibernateStatementBuilder">
<property name="fileNames">
<list>
<value>classpath*:/**/*-dynamic.xml</value><!--这里我们指定要加载某个文件夹下所有以-dynamic.xml结尾的文件 -->
</list>
</property>
</bean>
<bean id="baseHibernateDAO" class="com.haier.openplatform.dao.hibernate.BaseDAOHibernateImpl" abstract="true">
<property name="sessionFactory">
<ref bean="sessionFactory"/>
</property>
<property name="dynamicStatementBuilder" ref="dynamicStatementBuilder"/>
</bean>
dao层代码
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/**
* Hibernate实现的DAO层
* @param <T> DAO操作的对象类型
* @param <ID> 主键类型
* @author WangXuzheng
*
*/
public class SimpleHibernateDAO<T,ID extends Serializable> implements BaseDAO<T, ID>,InitializingBean{
private static final Logger LOGER = LoggerFactory.getLogger(SimpleHibernateDAO.class);
protected SessionFactory sessionFactory;
protected Class<T> entityClass;
/**
* 模板缓存
*/
protected Map<String, StatementTemplate> templateCache;
protected DynamicHibernateStatementBuilder dynamicStatementBuilder;
/**
* 通过子类的泛型定义取得对象类型Class.
* eg.
* public class UserDao extends SimpleHibernateDao<User, Long>
*/
public SimpleHibernateDAO() {
this.entityClass = Reflections.getSuperClassGenricType(getClass());
}
/**
* 取得sessionFactory.
*/
public SessionFactory getSessionFactory() {
return sessionFactory;
}
/**
* 采用@Autowired按类型注入SessionFactory, 当有多个SesionFactory的时候在子类重载本函数.
*/
public void setSessionFactory(final SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
public void setDynamicStatementBuilder(DynamicHibernateStatementBuilder dynamicStatementBuilder) {
this.dynamicStatementBuilder = dynamicStatementBuilder;
}
/**
* 取得当前Session.
*/
public Session getSession() {
return sessionFactory.getCurrentSession();
}
/**
* 保存新增或修改的对象.
*/
@Override
public void save(final T entity) {
Validate.notNull(entity, "entity不能为空");
getSession().save(entity);
LOGER.debug("save entity: {}", entity);
}
/**
* 删除对象.
*
* @param entity 对象必须是session中的对象或含id属性的transient对象.
*/
@Override
public void delete(final T entity) {
if(entity == null){
return;
}
getSession().delete(entity);
LOGER.debug("delete entity: {}", entity);
}
/**
* 按id删除对象.
*/
@Override
public void delete(final ID id) {
Validate.notNull(id, "id不能为空");
delete(get(id));
LOGER.debug("delete entity {},id is {}", entityClass.getSimpleName(), id);
}
/**
* 按id获取对象.
*/
@SuppressWarnings("unchecked")
@Override
public T get(final ID id) {
Validate.notNull(id, "id不能为空");
return (T) getSession().get(entityClass, id);
}
/**
* 按id列表获取对象列表.
*/
public List<T> get(final Collection<ID> ids) {
return find(Restrictions.in(getIdName(), ids));
}
/**
* 获取全部对象.
*/
@Override
public List<T> getAll() {
return find();
}
/**
* 获取全部对象, 支持按属性行序.
*/
@SuppressWarnings("unchecked")
public List<T> getAll(String orderByProperty, boolean isAsc) {
Criteria c = createCriteria();
if (isAsc) {
c.addOrder(Order.asc(orderByProperty));
} else {
c.addOrder(Order.desc(orderByProperty));
}
return c.list();
}
/**
* 按属性查找对象列表, 匹配方式为相等.
*/
public List<T> findBy(final String propertyName, final Object value) {
Criterion criterion = Restrictions.eq(propertyName, value);
return find(criterion);
}
/**
* 按属性查找唯一对象, 匹配方式为相等.
*/
@SuppressWarnings("unchecked")
@Override
public T findUniqueBy(final String propertyName, final Object value) {
Criterion criterion = Restrictions.eq(propertyName, value);
return ((T) createCriteria(criterion).uniqueResult());
}
/**
* 按HQL查询对象列表.
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findByHQL(final String hql, final Object... values) {
return createHQLQuery(hql, values).list();
}
/**
* 按HQL查询对象列表，并将对象封装成指定的对象
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findByHQLRowMapper(RowMapper<X> rowMapper,final String hql, final Object... values) {
Validate.notNull(rowMapper, "rowMapper不能为空！");
List<Object[]> result = createHQLQuery(hql, values).list();
return buildListResultFromRowMapper(rowMapper, result);
}
protected <X> List<X> buildListResultFromRowMapper(RowMapper<X> rowMapper, List<Object[]> result) {
List<X> rs = new ArrayList<X>(result.size());
for(Object[] obj : result){
rs.add(rowMapper.fromColumn(obj));
}
return rs;
}
/**
* 按SQL查询对象列表.
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findBySQLRowMapper(RowMapper<X> rowMapper,final String sql, final Object... values) {
Validate.notNull(rowMapper, "rowMapper不能为空！");
List<Object[]> result = createSQLQuery(sql, values).list();
return buildListResultFromRowMapper(rowMapper, result);
}
/**
* 按SQL查询对象列表,并将结果集转换成指定的对象列表
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findBySQL(final String sql, final Object... values) {
return createSQLQuery(sql, values).list();
}
/**
* 按HQL查询对象列表.
*
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findByHQL(final String hql, final Map<String, ?> values) {
return createHQLQuery(hql, values).list();
}
/**
* 按HQL查询对象列表,并将结果集封装成对象列表
*
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findByHQLRowMapper(RowMapper<X> rowMapper,final String hql, final Map<String, ?> values) {
Validate.notNull(rowMapper, "rowMapper不能为空！");
List<Object[]> result = createHQLQuery(hql, values).list();
return buildListResultFromRowMapper(rowMapper, result);
}
/**
* 按SQL查询对象列表.
* @param sql SQL查询语句
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findBySQL(final String sql, final Map<String, ?> values) {
return createSQLQuery(sql, values).list();
}
/**
* 查询在xxx.hbm.xml中配置的查询语句
* @param queryName 查询的名称
* @param parameters 参数
* @return
*/
public <X> List<X> findByNamedQuery(final String queryName, final Map<String, ?> parameters) {
StatementTemplate statementTemplate = templateCache.get(queryName);
String statement = processTemplate(statementTemplate,parameters);
if(statementTemplate.getType() == StatementTemplate.TYPE.HQL){
return this.findByHQL(statement);
}else{
return this.findBySQL(statement);
}
}
/**
* 查询在xxx.hbm.xml中配置的查询语句
* @param rowMapper
* @param queryName 查询的名称
* @param parameters 参数
* @return
*/
public <X> List<X> findByNamedQuery(RowMapper<X> rowMapper,final String queryName, final Map<String, ?> parameters) {
StatementTemplate statementTemplate = templateCache.get(queryName);
String statement = processTemplate(statementTemplate,parameters);
if(statementTemplate.getType() == StatementTemplate.TYPE.HQL){
return this.findByHQLRowMapper(rowMapper,statement);
}else{
return this.findBySQLRowMapper(rowMapper,statement);
}
}
/**
* 按SQL查询对象列表,并将结果集封装成对象列表
* @param sql SQL查询语句
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> List<X> findBySQLRowMapper(RowMapper<X> rowMapper,final String sql, final Map<String, ?> values) {
Validate.notNull(rowMapper, "rowMapper不能为空！");
List<Object[]> result = createSQLQuery(sql, values).list();
return buildListResultFromRowMapper(rowMapper, result);
}
/**
* 按HQL查询唯一对象.
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> X findUniqueByHQL(final String hql, final Object... values) {
return (X) createHQLQuery(hql, values).uniqueResult();
}
/**
* 按SQL查询唯一对象.
*
* @param values 数量可变的参数,按顺序绑定.
*/
@SuppressWarnings("unchecked")
public <X> X findUniqueBySQL(final String sql, final Object... values) {
return (X) createSQLQuery(sql, values).uniqueResult();
}
/**
* 按HQL查询唯一对象.
*
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> X findUniqueByHQL(final String hql, final Map<String, ?> values) {
return (X) createHQLQuery(hql, values).uniqueResult();
}
/**
* 按HQL查询唯一对象.
* @param sql sql语句
* @param values 命名参数,按名称绑定.
*/
@SuppressWarnings("unchecked")
public <X> X findUniqueBySQL(final String sql, final Map<String, ?> values) {
return (X) createSQLQuery(sql, values).uniqueResult();
}
/**
* 执行HQL进行批量修改/删除操作.
*
* @param values 数量可变的参数,按顺序绑定.
* @return 更新记录数.
*/
public int batchExecuteHQL(final String hql, final Object... values) {
return createHQLQuery(hql, values).executeUpdate();
}
/**
* 执行SQL进行批量修改/删除操作.
*
* @param sql sql语句
* @param values 数量可变的参数,按顺序绑定.
* @return 更新记录数.
*/
public int batchExecuteSQL(final String sql, final Object... values) {
return createSQLQuery(sql, values).executeUpdate();
}
/**
* 执行HQL进行批量修改/删除操作.
*
* @param values 命名参数,按名称绑定.
* @return 更新记录数.
*/
public int batchExecuteHQL(final String hql, final Map<String, ?> values) {
return createHQLQuery(hql, values).executeUpdate();
}
/**
* 执行SQL进行批量修改/删除操作.
*
* @param values 命名参数,按名称绑定.
* @return 更新记录数.
*/
public int batchExecuteSQL(final String sql, final Map<String, ?> values) {
return createSQLQuery(sql, values).executeUpdate();
}
/**
* 根据查询HQL与参数列表创建Query对象.
* 与find()函数可进行更加灵活的操作.
*
* @param values 数量可变的参数,按顺序绑定.
*/
public Query createHQLQuery(final String queryString, final Object... values) {
Query query = getSession().createQuery(queryString);
if (values != null) {
for (int i = 0; i < values.length; i++) {
query.setParameter(i, values[i]);
}
}
return query;
}
/**
* 根据查询SQL与参数列表创建Query对象.
* 与find()函数可进行更加灵活的操作.
* @param sqlQueryString sql语句
*
* @param values 数量可变的参数,按顺序绑定.
*/
public Query createSQLQuery(final String sqlQueryString, final Object... values) {
Query query = getSession().createSQLQuery(sqlQueryString);
if (values != null) {
for (int i = 0; i < values.length; i++) {
query.setParameter(i, values[i]);
}
}
return query;
}
/**
* 根据查询HQL与参数列表创建Query对象.
* 与find()函数可进行更加灵活的操作.
*
* @param values 命名参数,按名称绑定.
*/
public Query createHQLQuery(final String queryString, final Map<String, ?> values) {
Query query = getSession().createQuery(queryString);
if (values != null) {
query.setProperties(values);
}
return query;
}
/**
* 根据查询SQL与参数列表创建Query对象.
* 与find()函数可进行更加灵活的操作.
* @param queryString SQL语句
* @param values 命名参数,按名称绑定.
*/
public Query createSQLQuery(final String queryString, final Map<String, ?> values) {
Query query = getSession().createSQLQuery(queryString);
if (values != null) {
query.setProperties(values);
}
return query;
}
/**
* 按Criteria查询对象列表.
*
* @param criterions 数量可变的Criterion.
*/
@SuppressWarnings("unchecked")
public List<T> find(final Criterion... criterions) {
return createCriteria(criterions).list();
}
/**
* 按Criteria查询唯一对象.
*
* @param criterions 数量可变的Criterion.
*/
@SuppressWarnings("unchecked")
public T findUnique(final Criterion... criterions) {
return (T) createCriteria(criterions).uniqueResult();
}
/**
* 根据Criterion条件创建Criteria.
* 与find()函数可进行更加灵活的操作.
*
* @param criterions 数量可变的Criterion.
*/
public Criteria createCriteria(final Criterion... criterions) {
Criteria criteria = getSession().createCriteria(entityClass);
for (Criterion c : criterions) {
criteria.add(c);
}
return criteria;
}
/**
* 初始化对象.
* 使用load()方法得到的仅是对象Proxy, 在传到View层前需要进行初始化.
* 如果传入entity, 则只初始化entity的直接属性,但不会初始化延迟加载的关联集合和属性.
* 如需初始化关联属性,需执行:
* Hibernate.initialize(user.getRoles())，初始化User的直接属性和关联集合.
* Hibernate.initialize(user.getDescription())，初始化User的直接属性和延迟加载的Description属性.
*/
public void initProxyObject(Object proxy) {
Hibernate.initialize(proxy);
}
/**
* Flush当前Session.
*/
public void flush() {
getSession().flush();
}
/**
* 为Query添加distinct transformer.
* 预加载关联对象的HQL会引起主对象重复, 需要进行distinct处理.
*/
public Query distinct(Query query) {
query.setResultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY);
return query;
}
/**
* 为Criteria添加distinct transformer.
* 预加载关联对象的HQL会引起主对象重复, 需要进行distinct处理.
*/
public Criteria distinct(Criteria criteria) {
criteria.setResultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY);
return criteria;
}
/**
* 取得对象的主键名.
*/
public String getIdName() {
ClassMetadata meta = getSessionFactory().getClassMetadata(entityClass);
return meta.getIdentifierPropertyName();
}
/**
* 判断对象的属性值在数据库内是否唯一.
*
* 在修改对象的情景下,如果属性新修改的值(value)等于属性原来的值(orgValue)则不作比较.
*/
public boolean isPropertyUnique(final String propertyName, final Object newValue, final Object oldValue) {
if (newValue == null || newValue.equals(oldValue)) {
return true;
}
Object object = findUniqueBy(propertyName, newValue);
return (object == null);
}
@Override
public void update(T object) {
getSession().update(object);
}
@SuppressWarnings("unchecked")
@Override
public T load(ID id) {
return (T) getSession().load(this.entityClass, id);
}
/**
* 将list转化为数组
* @param list
* @return
*/
protected Criterion[] list2Array(List<Criterion> list){
if(list == null){
return new Criterion[0];
}
Criterion[] result = new Criterion[list.size()];
for(int i = 0; i < list.size(); i++){
result[i] = list.get(i);
}
return result;
}
@Override
public void afterPropertiesSet() throws Exception {
templateCache = new HashMap<String, StatementTemplate>();
if(this.dynamicStatementBuilder == null){
this.dynamicStatementBuilder = new NoneDynamicHibernateStatementBuilder();
}
dynamicStatementBuilder.init();
Map<String,String> namedHQLQueries = dynamicStatementBuilder.getNamedHQLQueries();
Map<String,String> namedSQLQueries = dynamicStatementBuilder.getNamedSQLQueries();
Configuration configuration = new Configuration();
configuration.setNumberFormat("#");
StringTemplateLoader stringLoader = new StringTemplateLoader();
for(Entry<String, String> entry : namedHQLQueries.entrySet()){
stringLoader.putTemplate(entry.getKey(), entry.getValue());
templateCache.put(entry.getKey(), new StatementTemplate(StatementTemplate.TYPE.HQL,new Template(entry.getKey(),new StringReader(entry.getValue()),configuration)));
}
for(Entry<String, String> entry : namedSQLQueries.entrySet()){
stringLoader.putTemplate(entry.getKey(), entry.getValue());
templateCache.put(entry.getKey(), new StatementTemplate(StatementTemplate.TYPE.SQL,new Template(entry.getKey(),new StringReader(entry.getValue()),configuration)));
}
configuration.setTemplateLoader(stringLoader);
}
protected String processTemplate(StatementTemplate statementTemplate,Map<String, ?> parameters){
StringWriter stringWriter = new StringWriter();
try {
statementTemplate.getTemplate().process(parameters, stringWriter);
} catch (Exception e) {
LOGER.error("处理DAO查询参数模板时发生错误：{}",e.toString());
throw new SysException(e);
}
return stringWriter.toString();
}
}
我们的SimpleHibernateDAO实现了InitializingBean,在其afterProperties方法中我们将调用DynamicHibernateStatementBuilder把语句缓存起来
上层方法调用示例-这个已经非常类似ibatis了
[java] view
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public List<Resource> getDescendants(Long userId,String code) {
Map<String, Object> values = new HashMap<String, Object>();
values.put("userId", String.valueOf(userId));
values.put("code", code);
values.put("type", String.valueOf(ResourceTypeEnum.URL_RESOURCE.getType()));
values.put("status", String.valueOf(ResourceStatusEnum.ACTIVE.getStatus()));
return this.findByNamedQuery(new ResourceRowMapper(),"resource.getDescendants", values);
}
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