C3P0连接池配置

1.新建c3p0.properties文件，放到src目录下，c3p0.properties文件样例

c3p0.jdbcUrl=jdbc:oracle:thin:@127.0.0.1:1521:orcl
c3p0.driverClass=oracle.jdbc.driver.OracleDriver
c3p0.user=test
c3p0.password=test

c3p0.acquireIncrement=3	
c3p0.idleConnectionTestPeriod=60	
c3p0.initialPoolSize=10	
c3p0.maxIdleTime=60	
c3p0.maxPoolSize=20	
c3p0.maxStatements=100	
c3p0.minPoolSize=5	

2.新建C3P0获取连接公共类

public class MyC3P0Utils{
	private static DataSource ds;

	private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>();
	static {
		ds = new ComboPooledDataSource();//直接使用即可，不用显示的配置，其会自动识别配置文件
	}

	public static DataSource getDataSource() {
		return ds;
	}

	public static Connection getConnection() {
		try {
//			 得到当前线程上绑定的连接
			Connection conn = tl.get();
			if (conn == null) { // 代表线程上没有绑定连接
				conn = ds.getConnection();
				tl.set(conn);
			}
			return conn;
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	public static void startTransaction() {
		try {
			// 得到当前线程上绑定连接开启事务
			Connection conn=getConnection();
			conn.setAutoCommit(false);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	public static void commitTransaction() {
		try {
			Connection conn = tl.get();
			if (conn != null) {
				conn.commit();
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	public static void closeConnection() {
		try {
			Connection conn = tl.get();
			if (conn != null) {
				conn.close();
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		} finally {
			tl.remove(); // 千万注意，解除当前线程上绑定的链接（从threadlocal容器中移除对应当前线程的链接）
		}
	}
}

3.导入C3P0相关jar包