Spring核心技术之JDBC支持

Spring核心技术之JDBC支持

概述

使用步骤

package com.jpzhutech.jdbc;

import java.sql.SQLException;

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

public class App {
private static ApplicationContext applicationContext = new ClassPathXmlApplicationContext("com/jpzhutech/jdbc/applicationContext.xml");

public static void main(String[] args) throws SQLException {

UserDao userDao = (UserDao)applicationContext.getBean("userDao");
//userDao.save();   //调用保存数据到数据中的方法

userDao.finById(19);
return;
}
}

package com.jpzhutech.jdbc;

public class Admin {
private int id;
private String userName;
private String pwd;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public Admin(int id, String userName, String pwd) {
this.id = id;
this.userName = userName;
this.pwd = pwd;
}
public Admin() {
super();
}
@Override
public String toString() {
return "Admin [id=" + id + ", userName=" + userName + ", pwd=" + pwd
+ "]";
}

}

package com.jpzhutech.jdbc;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

public class UserDao {

//创建连接池以及连接池对象，IOC注入方式
private DataSource dataSource ;

public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
}

public void save(){
//将数据保存到数据库中，采用c3p0连接池操作数据库
String sql = "insert into admin(id,username,pwd) values(10000,'贾敏','123456')";  //创建SQL语句
//使用Jdbc模板工具类来简化jdbc操作
JdbcTemplate jdbcTemplate = new JdbcTemplate();
jdbcTemplate.setDataSource(dataSource);   //使用set方法传递数据源

try {
jdbcTemplate.update(sql);
} catch (Exception e) {
System.out.println("插入不成功");   //只能用异常的方式处理插入不成功的情况
//当发生插入异常时，需要将此情况报告给客户端，让用户看见没有插入成功
}
}

public Admin  finById(int id ){
String sql = "select * from admin where id=? ";
JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
//Map<String, Object> queryForMap = jdbcTemplate.queryForMap(sql,id);
//List<Map<String, Object>> list = jdbcTemplate.queryForList(sql);
//System.out.println(queryForMap);
//System.out.println(list);

//下面的方法才是比较常用的方法
List<Admin> list = jdbcTemplate.query(sql, new RowMapper<Admin>(){

//如何封装一行记录
@Override
public Admin mapRow(ResultSet rs, int index) throws SQLException {
Admin admin = new Admin();
admin.setId(rs.getInt("id"));
admin.setUserName("username");
admin.setPwd("pwd");
return admin;
}

},id);
System.out.println(list.toString());
return null;
}
}

<?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:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
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">

<!-- 创建数据源对象，创建c3p0连接池 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="org.postgresql.Driver"></property>
<property name="jdbcUrl" value="jdbc:postgresql://192.168.100.120:5432/postgres"></property>
<property name="user" value="postgres"></property>
<!--   <property name="password"></property> -->
<property name="initialPoolSize" value="3"></property>
<property name="maxPoolSize" value="10"></property>
<property name="maxStatements" value="100"></property>
<property name="acquireIncrement" value="2"></property>
</bean>

<!-- 创建UserDao对象 -->
<bean id ="userDao" class="com.jpzhutech.jdbc.UserDao">
<property name="dataSource" ref="dataSource"></property>
</bean>
</beans>

参考资料