您的位置:首页 > 编程语言 > Java开发

[Spring学习笔记 6 ] Spring JDBC 详解

2013-11-28 02:17 316 查看
项目使用maven管理,pom.xml和项目组织如下:

<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>com.amos.spring</groupId>
<artifactId>Lspring_JDBC</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>Lspring_JDBC</name>
<url>http://maven.apache.org</url>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.2</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>3.2.4.RELEASE</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>3.2.4.RELEASE</version>
</dependency>
<dependency>
<groupId> org.aspectj</groupId>
<artifactId> aspectjweaver</artifactId>
<version> 1.6.11</version>
</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>5.1.24</version>
</dependency>

</dependencies>
</project>




逻辑步骤如下:

1.直接看代码:传统操作数据库方式

package com.amos.spring.dao;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.sql.DataSource;

import org.apache.commons.dbcp.BasicDataSource;

/**
* @ClassName: 传统的操作数据库的方式
* @Description: TODO
* @author: amosli
* @email:amosli@infomorrow.com
* @date Nov 28, 2013 2:03:23 AM
*/
public class DbUtil {
private static DataSource datasource;
static {
// 初始化连接池
BasicDataSource dSource = new BasicDataSource();
// 设置连接池的属性
dSource.setDriverClassName("com.mysql.jdbc.Driver");
dSource.setUrl("jdbc:mysql:///spring_learn");
dSource.setUsername("root");
dSource.setPassword("root");
datasource = dSource;
}

public static Connection getConn() throws SQLException {
return datasource.getConnection();
}

public static void close(ResultSet rs, Statement stmt, Connection conn) {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}


2.定义一个person接口

package com.amos.spring.dao;

import java.util.List;

import com.amos.spring.model.Person;

/**
* @ClassName: IpersonDao
* @Description: TODO
* @author: amosli
* @email:amosli@infomorrow.com
* @date Nov 27, 2013 12:35:48 AM
*/
public interface IpersonDao {
void save(Person p);

void update(Long id, Person p);

void delete(Long id);

List<Person> loadAll();

}


3.使用最原始的操作数据库方式

package com.amos.spring.impl;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;

import com.amos.spring.dao.DbUtil;
import com.amos.spring.dao.IpersonDao;
import com.amos.spring.model.Person;

/**
* @ClassName: PersonDaoImplJdbcOld
* @Description: 最原始的操作
* @author: amosli
* @email:amosli@infomorrow.com
* @date Nov 28, 2013 12:15:20 AM
*/
public class PersonDaoImplJdbcOld implements IpersonDao {

public void save(Person p) {
// 获得连接
// 获得一个连接Connection
Connection conn = null;
Statement stmt = null;
try {
conn = DbUtil.getConn();
// 开取事务
conn.setAutoCommit(false);
// 初始化相关的Statment对象
stmt = conn.createStatement();
String sql = "insert into person(name,age) values('" + p.getName() + "'," + p.getAge() + ")";
stmt.executeUpdate(sql);
// 提交事务
conn.commit();
} catch (Exception e) {
try {
if (conn != null)
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
} finally {
DbUtil.close(null, stmt, conn);
}
}

public void update(Long id, Person p) {
// 获得一个连接Connection
Connection conn = null;
Statement stmt = null;
try {
conn = DbUtil.getConn();
// 开取事务
conn.setAutoCommit(false);
// 初始化相关的Statment对象
stmt = conn.createStatement();
String sql = "update person set name = '" + p.getName() + "',age='" + p.getAge() + "' where id='" + p.getId() + "'";
stmt.executeUpdate(sql);
// 提交事务
conn.commit();
} catch (Exception e) {
try {
if (conn != null)
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
} finally {
DbUtil.close(null, stmt, conn);
}
}

public void delete(Long id) {
Connection conn = null;
Statement stmt = null;
try {
conn = DbUtil.getConn();
// 开取事务
conn.setAutoCommit(false);
// 初始化相关的Statment对象
stmt = conn.createStatement();
String sql = "delete person where id='"+id+"'";
stmt.executeUpdate(sql);
// 提交事务
conn.commit();
} catch (Exception e) {
try {
if (conn != null)
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
} finally {
DbUtil.close(null, stmt, conn);
}
}

public List<Person> loadAll() {
// TODO Auto-generated method stub
return null;
}

}


4.发现有很多冗余的地方,关于数据库的开启关闭都是相同的,怎么抽象出来共有的地方???

定义一个接口,使用内部类实现这个接口,然后调用这个方法。

package com.amos.spring.impl;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;

import com.amos.spring.dao.DbUtil;
import com.amos.spring.dao.IpersonDao;
import com.amos.spring.model.Person;

/**
* @ClassName: PersonDaoImplJdbc
* @Description: 把相同的操作封装成一个接口,用内部 类实现接口
* @author: amosli
* @email:amosli@infomorrow.com
* @date Nov 27, 2013 11:37:50 PM
*/
public class PersonDaoImplJdbc implements IpersonDao {

interface UpdateOperation {
/**
* 把各种各样的操作封装成一个接口
*
* @param stmt
* @throws SQLException
*/
void execute(Statement stmt) throws SQLException;
}

/**
* 执行数据库操作
*/
public void excuteUpdate(UpdateOperation operation) {
// 获得一个连接Connection
Connection conn = null;
Statement stmt = null;
try {
conn = DbUtil.getConn();
// 开取事务
conn.setAutoCommit(false);
// 初始化相关的Statment对象
stmt = conn.createStatement();
// 执行具体的操作
operation.execute(stmt);
// 提交事务
conn.commit();
} catch (Exception e) {
try {
if (conn != null)
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
} finally {
DbUtil.close(null, stmt, conn);
}
}

public void save(final Person p) {
// save中就只有核心的业务代码了
excuteUpdate(new UpdateOperation() {
public void execute(Statement stmt) throws SQLException {
String sql = "insert into person(name,age) values('" + p.getName() + "'," + p.getAge() + ")";
stmt.executeUpdate(sql);
}
});
}

public void update(final Long id, final Person p) {
excuteUpdate(new UpdateOperation() {
public void execute(Statement stmt) throws SQLException {
String sql = "update person set name = '" + p.getName() + "',age='" + p.getAge() + "' where id='" + id + "'";
stmt.executeUpdate(sql);
}
});
}

public void delete(final Long id) {
excuteUpdate(new UpdateOperation() {
public void execute(Statement stmt) throws SQLException {
String sql = "delete person where id='" + id + "'";
stmt.executeUpdate(sql);
}
});

}

public List<Person> loadAll() {
return null;
}

}


5.怎么才能进一步优化代码???那就把刚才核心代码抽象成一个类,不仅person可以使用其他类也可以使用

如下代码:

package com.amos.spring.impl;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;

import com.amos.spring.dao.DbUtil;
import com.amos.spring.dao.IpersonDao;
import com.amos.spring.model.Person;

/**
* @ClassName: PersonDaoImplJdbcTemplate
* @Description: 代码继续优化,把实现接口的方法提取出来
* @author: amosli
* @email:amosli@infomorrow.com
* @date Nov 27, 2013 11:51:06 PM
*/
public class PersonDaoImplJdbcTemplate implements IpersonDao {

interface UpdateOperation {
/**
* 把各种各样的操作封装成一个接口
*
* @param stmt
* @throws SQLException
*/
void execute(Statement stmt) throws SQLException;
}

/**
* 执行数据库操作
*/
public void excuteUpdate(UpdateOperation operation) {
// 获得一个连接Connection
Connection conn = null;
Statement stmt = null;
try {
conn = DbUtil.getConn();
// 开取事务
conn.setAutoCommit(false);
// 初始化相关的Statment对象
stmt = conn.createStatement();
// 执行具体的操作
operation.execute(stmt);
// 提交事务
conn.commit();
} catch (Exception e) {
try {
if (conn != null)
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
} finally {
DbUtil.close(null, stmt, conn);
}
}

public void excuteSql(final String sql) {
excuteUpdate(new UpdateOperation() {
public void execute(Statement stmt) throws SQLException {
stmt.executeUpdate(sql);
}
});
}

public void save(final Person p) {
// save中就只有核心的业务代码了
String sql = "insert into person(name,age) values('" + p.getName() + "'," + p.getAge() + ")";
excuteSql(sql);
}

public void update(final Long id, final Person p) {
String sql = "update person set name = '" + p.getName() + "',age='" + p.getAge() + "' where id='" + id + "'";
excuteSql(sql);
}

public void delete(final Long id) {
String sql = "delete person where id='" + id + "'";
excuteSql(sql);
}

public List<Person> loadAll() {
return null;
}

}


6.写个testcase测试下吧:

package com.amos.spring.dao;

import com.amos.spring.impl.PersonDaoImplJdbcTemplateBest;
import com.amos.spring.model.Person;

/**
* @ClassName: PersonDaoTest
* @Description: 把关于数据库操作的类封装起来进行调用
* @author: amosli
* @email:amosli@infomorrow.com
* @date Nov 28, 2013 1:59:04 AM
*/
public class PersonDaoTest {
private static IpersonDao dao;

public static void main(String args[]) {
dao = new PersonDaoImplJdbcTemplateBest();
Person person = new Person();
person.setName("运哥");
person.setAge(29);
dao.save(person);
}
}


然后去查看数据库即可。

数据库非常简单,person数据库生成代码:

DROP TABLE IF EXISTS `person`;
CREATE TABLE `person` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(1000) DEFAULT NULL,
`age` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=gbk;

-- ----------------------------
-- Records of person
-- ----------------------------
INSERT INTO `person` VALUES ('1', '运哥', '23');


7.使用spring 又该如何呢?使用JdbcTemplate模板

package com.amos.spring.impl;

import java.util.List;

import org.springframework.jdbc.core.JdbcTemplate;

import com.amos.spring.dao.IpersonDao;
import com.amos.spring.model.Person;

/**
* @ClassName: SpringJdbcTemplateBest
* @Description: 使用spring 框架进行操作数据库
* @author: amosli
* @email:amosli@infomorrow.com
* @date Nov 28, 2013 1:01:27 AM
*/
public class SpringJdbcTemplateBest implements IpersonDao {
private JdbcTemplate jdbcTemplate;
public List<Person> loadAll() {
return null;
}

public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}

public void save(Person p) {
String sql = "insert into person(name,age) values('" + p.getName() + "'," + p.getAge() + ")";
System.out.println("save:" + sql);
jdbcTemplate.update(sql);
}

public void update(Long id, Person p) {
String sql = "update person set name = '" + p.getName() + "',age='" + p.getAge() + "' where id='" + id + "'";
jdbcTemplate.update(sql);
}

public void delete(Long id) {
String sql = "delete person where id='" + id + "'";
jdbcTemplate.update(sql);
}

}


8.配置bean.xml文件

<?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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd ">
<context:property-placeholder location="db.properties" />
<!-- 配置连接池 -->
<bean id="mydataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="${db.driverClassName}"></property>
<property name="url" value="${db.url}"></property>
<property name="username" value="${db.username}"></property>
<property name="password" value="${db.password}"></property>
</bean>
<!-- 配置jdbctemplate -->
<bean id="myjdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="mydataSource"></property>
</bean>
<bean id="personDao" class="com.amos.spring.impl.SpringJdbcTemplateBest">
<property name="jdbcTemplate" ref="myjdbcTemplate"></property>
</bean>
</beans>


db.properties:

db.driverClassName=com.mysql.jdbc.Driver
db.url=jdbc:mysql:///spring_learn
db.username=root
db.password=root


9.写个testcase测试一下:

package com.amos.spring.dao;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.amos.spring.model.Person;

public class SpringPersonDaoTest {
private static IpersonDao dao;
//    @Test
public static void main(String args[]){
ApplicationContext acx = new ClassPathXmlApplicationContext("bean.xml");
dao = acx.getBean(IpersonDao.class);
Person person = new Person();
person.setName("运哥");
person.setAge(33);
dao.save(person);
}
}
内容来自用户分享和网络整理,不保证内容的准确性,如有侵权内容,可联系管理员处理 点击这里给我发消息
标签: