文章目录

• 1. 创建项目的基础配置
• 1.1 引入项目中所需要的所有包(pom.xml)
• 1.2 配置applicationContext.xml文件
• 1.3 准备Domain
• 1.4 完成Repository的功能
• 1.5 测试集成是否成功

• 2.1 单个条件的查询
• 2.2 多个条件查询
• 2.3 查询+分页+排序

• 3.1 功能介绍

• 3.3 功能测试
• 3.3.1 单个条件查询
• 3.3.2 多个条件查询
• 3.3.3 条件+排序分页功能

• 4.1 BaseQuery:公共的分页条件
• 4.2 EmployeeQuery:Employee特有的一些条件
• 4.3 功能测试

1. 创建项目的基础配置

1.1 引入项目中所需要的所有包(pom.xml)

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>cn.itsource</groupId>
<artifactId>yxb</artifactId>
<version>1.0-SNAPSHOT</version>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<org.springframework.version>4.2.5.RELEASE</org.springframework.version>
<org.hibernate.version>4.3.8.Final</org.hibernate.version>
<spring-data-jpa.version>1.9.0.RELEASE</spring-data-jpa.version>
<com.fasterxml.jackson.version>2.5.0</com.fasterxml.jackson.version>
<org.slf4j.version>1.6.1</org.slf4j.version>
</properties>
<dependencies>
<!-- Spring的支持包 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${org.springframework.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${org.springframework.version}</version>
<scope>test</scope>
</dependency>
<!-- 引入web前端的支持 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<!-- SpringMCV上传需要用到io包-->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-io</artifactId>
<version>1.3.2</version>
</dependency>
<!-- 文件上传用到的包 -->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2.2</version>
</dependency>
<!-- SpringMVC的json支持包 -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${com.fasterxml.jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${com.fasterxml.jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${com.fasterxml.jackson.version}</version>
</dependency>
<!-- hibernate的支持包 -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>${org.hibernate.version}</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>${org.hibernate.version}</version>
</dependency>
<!-- SpringData的支持包 -->
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>${spring-data-jpa.version}</version>
</dependency>
<!-- SpringData的擴展包 -->
<dependency>
<groupId>com.github.wenhao</groupId>
<artifactId>jpa-spec</artifactId>
<version>3.1.1</version>
<!-- 把所有的依賴都去掉 -->
<exclusions>
<exclusion>
<groupId>*</groupId>
<artifactId>*</artifactId>
</exclusion>
</exclusions>
</dependency>

<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.2.2</version>
</dependency>

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.6</version>
</dependency>

<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.5</version>
</dependency>
<!-- 測試包 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<!-- 这个scope 只能作用在编译和测试时，同时没有传递性。表示在运行的时候不添加此jar文件 -->
<scope>provided</scope>
</dependency>
<!-- 日志文件 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${org.slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${org.slf4j.version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.14</version>
</dependency>
<!-- 代码生成器模版技术 -->
<dependency>
<groupId>org.apache.velocity</groupId>
<artifactId>velocity</artifactId>
<version>1.6</version>
</dependency>
<!-- shiro的支持包 -->
<dependency>
<groupId>org.apache.shiro</groupId>
<artifactId>shiro-all</artifactId>
<version>1.4.0</version>
<type>pom</type>
</dependency>
<!-- shiro与Spring的集成包 -->
<dependency>
<groupId>org.apache.shiro</groupId>
<artifactId>shiro-spring</artifactId>
<version>1.4.0</version>
</dependency>
<!-- poi支持的jar包 -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.11</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.11</version>
</dependency>
<!-- 图片压缩功能 -->
<!-- 缩略图 -->
<dependency>
<groupId>net.coobird</groupId>
<artifactId>thumbnailator</artifactId>
<version>0.4.6</version>
</dependency>
<!-- 定时调度 -->
<dependency>
<groupId>quartz</groupId>
<artifactId>quartz</artifactId>
<version>1.5.2</version>
</dependency>
<!-- 邮件支持 -->
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4.1</version>
</dependency>
</dependencies>

<build>
<finalName>yxb</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>8.1.15.v20140411</version>
<configuration>
<stopPort>9966</stopPort>
<stopKey>foo</stopKey>
<webAppConfig>
<contextPath>/</contextPath>
</webAppConfig>
</configuration>
</plugin>
</plugins>
</build>
</project>

1.2 配置applicationContext.xml文件

注意:修改相应的包扫描(每个系统都会有不一样的地方)
里面的路径需要注意不要配错，建表策略为false

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/data/jpa
http://www.springframework.org/schema/data/jpa/spring-jpa.xsd">

<!-- 扫描service部分的包 -->
<context:component-scan base-package="com.zpx.domain" />
<context:property-placeholder location="classpath:jdbc.properties" />

<!-- 配置连接池 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<!--连接数据4个属性 -->
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<!--maxActive: 最大连接数量 -->
<property name="maxActive" value="150" />
<!--minIdle: 最小空闲连接 -->
<property name="minIdle" value="5" />
<!--maxIdle: 最大空闲连接 -->
<property name="maxIdle" value="20" />
<!--initialSize: 初始化连接 -->
<property name="initialSize" value="30" />
<!-- 用来配置数据库断开后自动连接的 -->
<!-- 连接被泄露时是否打印 -->
<property name="logAbandoned" value="true" />
<!--removeAbandoned: 是否自动回收超时连接 -->
<property name="removeAbandoned" value="true" />
<!--removeAbandonedTimeout: 超时时间(以秒数为单位) -->
<property name="removeAbandonedTimeout" value="10" />
<!--maxWait: 超时等待时间以毫秒为单位 1000等于60秒 -->
<property name="maxWait" value="1000" />
<!-- 在空闲连接回收器线程运行期间休眠的时间值,以毫秒为单位. -->
<property name="timeBetweenEvictionRunsMillis" value="10000" />
<!-- 在每次空闲连接回收器线程(如果有)运行时检查的连接数量 -->
<property name="numTestsPerEvictionRun" value="10" />
<!-- 1000 * 60 * 30 连接在池中保持空闲而不被空闲连接回收器线程 -->
<property name="minEvictableIdleTimeMillis" value="10000" />
<property name="validationQuery" value="SELECT NOW() FROM DUAL" />
</bean>

<!-- 集成hibernate的jpa功能 -->
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<!--待扫描的实体类包，不再需要persistence.xml了 -->
<property name="packagesToScan" value="com.zpx.domain" />
<!-- 3.配置JPA的实现 -->
<!-- private JpaVendorAdapter jpaVendorAdapter; -->
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<!-- org.springframework.orm.jpa.vendor.AbstractJpaVendorAdapter -->
<!-- private boolean showSql = false;是否显示sql语句 -->
<property name="showSql" value="true" />
<!-- private boolean generateDdl = false;是否建表 -->
<property name="generateDdl" value="false" />
<!-- private String databasePlatform;原来方言 -->
<property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" />
</bean>
</property>
</bean>

<!-- Jpa 事务配置 -->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<!-- 注解声明式事务管理 -->
<tx:annotation-driven />

<!-- Spring Data Jpa配置 ********************************************-->
<!-- base-package:扫描的包 -->
<jpa:repositories base-package="com.zpx.repository" transaction-manager-ref="transactionManager"
entity-manager-factory-ref="entityManagerFactory" />
</beans>

1.3 准备Domain

父类:BaseDomain

package com.zpx.domain;

import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;
//MappedSuperclass：表示当前类是父类
@MappedSuperclass
// 在JPA里面就表示是父类，不持久化到表
public class BaseDomain {
@Id
@GeneratedValue
protected Long id;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}

子类Employee

@Entity
@Table(name="employee")
public class Employee extends  BaseDomain {

private String username;
private String password;
private String email;
private Integer age;
//省略getter,setter与toString(注意:Alt+Insert可以自动生成)
}

1.4 完成Repository的功能

package com.zpx.repository;

import com.zpx.domain.Employee;
import org.springframework.data.jpa.repository.JpaRepository;

/**
* 必需继续JpaRepository<1v,2v>
*     1v:代表你要操作的是哪一个domain对象
*     2v:这个domain对象的主键的类型
*/
public interface EmployeeRepository extends JpaRepository<Employee, Long> {
}

1.5 测试集成是否成功

package com.zpx.repository;

import com.zpx.domain.Employee;
...
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class EmployeeRepositoryTest  {
@Autowired
private EmployeeRepository employeeRepository;
@Test
public void testFind() throws Exception{
List<Employee> emps = employeeRepository.findAll();
for (Employee emp :emps){
System.out.println(emp);
}
}
}

2. JpaSpecificationExecutor认识

• JpaSpecificationExecutor(JPA规则执行者)是JPA2.0提供的Criteria API的使用封装，可以用于动态生成Query来满足我们业务中的各种复杂场景。
• Spring Data JPA为我们提供了JpaSpecificationExecutor接口，只要简单实现toPredicate方法就可以实现复杂的查询。

public interface JpaSpecificationExecutor<T> {
T findOne(Specification<T> spec);
List<T> findAll(Specification<T> spec);
Page<T> findAll(Specification<T> spec, Pageable pageable);
List<T> findAll(Specification<T> spec, Sort sort);
long count(Specification<T> spec);
}

我们要使用这个接口中的方法,首先让我们的接口也去继承这个接口:

public interface EmployeeRepository extends JpaRepository<Employee,Long>,JpaSpecificationExecutor<Employee> { }

2.1 单个条件的查询

@Test
public void testJpaSpecificationExecutor()throws Exception{
/*
根据相应的规则（Specification），查询对应的数据
Predicate:where xxx=? and yyy=?
root：根，可以获取到类中的属性（xxx，yyy...）
CriteriaQuery：查询哪些字段，排序是什么(主要是把多个查询的条件连系起来)
CriteriaBuilder：字段之间是什么关系，如何生成一个查询条件，每一个查询条件都是什么方式
主要判断关系（和这个字段是相等，大于，小于like等）

*/
List<Employee> list = employeeRepository.findAll(new Specification<Employee>() {
@Override
public Predicate toPredicate(Root<Employee> root, CriteriaQuery<?> cq, CriteriaBuilder cb) {
//使用root拿到相应的username属性
Path usernamePath = root.get("username");
//为属性添加查询规则
Predicate predicate = cb.like(usernamePath, "%1%");
return predicate;
}
});
list.forEach(e-> System.out.println(e));
}

2.2 多个条件查询

@Test
public void testJpaSpecificationExecutor02()throws Exception{

List<Employee> list = employeeRepository.findAll(new Specification<Employee>() {
@Override
public Predicate toPredicate(Root<Employee> root, CriteriaQuery<?> cq, CriteriaBuilder cb) {
//使用root拿到相应的username属性
Path usernamePath = root.get("username");
//为属性添加查询规则
Predicate p1 = cb.like(usernamePath, "%1%");
Path emailPath = root.get("email");
Predicate p2 = cb.like(emailPath, "%2%");
//gt大于的意思
Path agePath = root.get("age");
Predicate p3 = cb.gt(agePath, 20);
//多个条件连接起来
Predicate predicate = cb.and(p1, p2, p3);
return predicate;
}
});
list.forEach(e-> System.out.println(e));
}

2.3 查询+分页+排序

@Test
public void testJpaSpecificationExecutor03()throws Exception{
Pageable pageable = new PageRequest(0,10);
Sort sort = new Sort(Sort.Direction.DESC,"age");

Page<Employee> page = employeeRepository.findAll(new Specification<Employee>() {
@Override
public Predicate toPredicate(Root<Employee> root, CriteriaQuery<?> cq, CriteriaBuilder cb) {
//使用root拿到相应的username属性
Path usernamePath = root.get("username");
//为属性添加查询规则
Predicate predicate = cb.like(usernamePath, "%1%");

return predicate;
}
}, pageable);
page.forEach(e-> System.out.println(e));
}

3. spec插件

这是一个对于咱们刚才的动态生成Query功能的一个封装版，如果我们使用这个插件，在完成查询与分页的时候功能会简单不少。
基于Spring Data Jpa的动态查询库 https://github.com/wenhao/jpa-spec

3.1 功能介绍

1. 兼容Spring Data Jpa 和JPA2.1接口。
2. Equal/NotEqual/Like/NotLike/In/NotIn支持可变参数, Equal/NotEqual 支持空(Null)值。
3. 每个条件支持关联查询。
4. 支持自定义条件查询。
5. 条件构建器。
6. 支持分页和排序。

3.2 在Maven中引入相应的包

pom.xml(咱们项目中已经引入):

<!--  jpa的SpecificationSpecification功能封装 -->
<dependency>
<groupId>com.github.wenhao</groupId>
<artifactId>jpa-spec</artifactId>
<version>3.1.1</version>
<!-- 把所有依赖都过滤 -->
<exclusions>
<exclusion>
<groupId>*</groupId>
<artifactId>*</artifactId>
</exclusion>
</exclusions>
</dependency>

3.3 功能测试

3.3.1 单个条件查询

@Test
public void testJpaSpac01()throws Exception{
//导包注意导入wenhao的包
//获取到查询的规则
Specification<Employee> spec = Specifications.<Employee>and()
.like("username","%1%")
.build();
//根据规则完成查询
List<Employee> list = employeeRepository.findAll(spec);
list.forEach(e-> System.out.println(e));
}

3.3.2 多个条件查询

@Test
public void testJpaSpec02()throws Exception{
//获取到查询的规则
Specification<Employee> spec = Specifications.<Employee>and()
.like("username", "%1%")
.like("email","%2%")
.gt("age",20)
.build();
//根据规则完成查询
List<Employee> list = employeeRepository.findAll(spec);
list.forEach(e-> System.out.println(e));
}

3.3.3 条件+排序分页功能

@Test
public void testJpaSpac03()throws Exception{
//先获取分页和排序对象
Sort sort = new Sort(Sort.Direction.valueOf("DESC"),"age");
Pageable pageable = new PageRequest(0,10,sort);
//导包注意导入wenhao的包
//获取到查询的规则
Specification<Employee> spec = Specifications.<Employee>and()
.like("username","%1%")
//              .like("email","%2%")
//             .gt("age",20)
.build();
//根据规则完成查询
Page<Employee> page = employeeRepository.findAll(spec, pageable);

page.forEach(e-> System.out.println(e));
}

Jpa-spec的功能还是比较简单实用的。其它一些功能，我们在项目用到再说相应的讲解。大家也可以去参照网络上相就的中文文档：
https://github.com/wenhao/jpa-spec/blob/master/docs/3.1.0_cn.md
https://www.w3cschool.cn/jpaspec/

4. Query查询条件

咱们每一个项目是做过高级查询与分页的，大家应该都清楚，查询的数据是从前端由客户输入(或者选择)传到后台的。那么，我们需要注意的情况有哪些呢？

1. 用户传的数据有0-n个(我们需要去判断)
2. 咱们必需要准备一个对象接收用户传过来的数据(使用Query对象)
3. 分页的条件对我们来说也是封装到Query对象中的
   接下来，我们要准备我们的Query对象：

4.1 BaseQuery:公共的分页条件

public abstract class BaseQuery {
//当前页
private int currentPage = 1;
//每条条数
private int pageSize = 10;
//排序字段名(如果前台没有传字段名，代表不需要做排序)
private String orderName;
//排序的规则
private String orderType = "ASC";
//写个抽象方法去规范子类获取Specification对象的名称必需叫:createSpec
public abstract Specification createSpec();
//创建排序对象
public Sort createSort(){
if(StringUtils.isNotBlank(orderName)){
//toUpperCase() 方法用于把字符串转换为大写。
return new Sort(Sort.Direction.valueOf(orderType.toUpperCase()),orderName);
}
return null;
}
public int getCurrentPage() {
return currentPage;
}
//第一页从0开始计算
public int getJpaCurrentPage() {
return currentPage-1;
}
public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public String getOrderName() {
return orderName;
}
public void setOrderName(String orderName) {
this.orderName = orderName;
}
public String getOrderType() {
return orderType;
}
public void setOrderType(String orderType) {
this.orderType = orderType;
}
}

4.2 EmployeeQuery:Employee特有的一些条件

public class EmployeeQuery extends BaseQuery {
private String username;
private String email;
private Integer age;
//返回咱们的查询条件 where username = ?
@Override
public Specification createSpec(){
/**
* like方法两个参数
*  1.查询的字段
*  2.这个字段条件对应的值
* like方法三个参数
*  1.boolean false，这个查询不执行
*  2.查询的字段
*  3.这个字段条件对应的值
*/
//抽取spac
Specification<Employee> spec = Specifications.<Employee>and()
.like(StringUtils.isNotBlank(username),"username", "%"+username+"%")
.like(StringUtils.isNotBlank(email),"email", "%"+email+"%")
.gt(age!=null,"age", age)
.build();
return spec;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
}

4.3 功能测试

//wendao抽取的查询并分页功能
@Test
public void testJpaSpecPageQuery()throws Exception{
EmployeeQuery query = new EmployeeQuery();
query.setUsername("1");
query.setOrderName("age");
query.setOrderType("DESC");
//调用被抽取的查询方法，拿到对象
Specification spec = query.createSpec();
//调用被抽取的分页方法，拿到对象
Sort sort = query.createSort();
//用sort创建page对象,并封装
Pageable pageable = new PageRequest(query.getJpaCurrentPage(), query.getPageSize(), sort);
//查询全部，传入对象
Page<Employee> page = employeeRepository.findAll(spec, pageable);
page.forEach(e-> System.out.println(e));
}