Java工具类之一DataSourse工具类（含有事务的工具类）

这个工具类比较实用，用于读写MySQL数据库，获得连接的一个工具类，同样最好是有一个配置文件c3p0-config.xml，文件名是固定的，最好不要更改，这样更换地址等信息的时候，不用修改源码。这里需要五个工具包（只使用了当时的版本）：

c3p0-0.9.1.2.jar      

commons-beanutils-1.8.3.jar

commons-dbutils-1.4.jar

commons-logging-1.1.1.jar

mysql-connector-java-5.1.39-bin.jar

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
	<default-config>
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">jdbc:mysql:///day38</property>
		<property name="user">root</property>
		<property name="password">root</property>
	</default-config>
</c3p0-config>

含有事务的DataSourse工具类代码

import java.sql.Connection;
import java.sql.SQLException;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class DataSourceUtils {
	private static DataSource ds=new ComboPooledDataSource();
	private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>();
	
	
	public static DataSource getDataSource(){
		return ds;
	}
	
	public static Connection getConnection() throws SQLException{
		Connection conn = tl.get();
		if(conn	== null){
			conn=ds.getConnection();
			
			tl.set(conn);
		}
		
		return conn;
	}
	
	public static void beginTransaction() throws SQLException{
		Connection conn = getConnection();
		
		conn.setAutoCommit(false);
	}
	
	public static void commitAndClose(){
		try {
			Connection conn = getConnection();
			
			if(conn != null){
				conn.commit();
			}
			
			closeConn(conn);
		} catch(Exception e){
			
		}
		
	}
	
	public static void rollbackAndClose(){
		try {
			Connection conn = getConnection();
			
			if(conn != null){
				conn.rollback();
			}
			
			closeConn(conn);
			
		} catch (SQLException e) {
			//
		}
	}
	private static void  closeConn(Connection conn){
		try {
			if(conn != null){
				conn.close();
			}
			tl.remove();
		} catch (Exception e) {
		}
		
		conn = null;
	}
}