如何启动JDBC Debug模式，打印JDBC诊断日志

1.下载Debug版本jar包

     首先要下载一个Debug版本的JDBC jar包，Debug版本的jar包命名形式为jdbcX_g.jar（如下图所示），如Oracle11g的Debug版本的jar包为jdbc6_g.jar。点击这里下载：http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-112010-090769.html 

2.启动Logging模式

     第一种方式：设置运行环境变量java -Doracle.jdbc.Trace=true ...（elipse中run->run configurations->arguments一栏）

     第二种方式：在程序中控制（建议采用这种方式）

MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
			String loader = Thread.currentThread().getContextClassLoader().toString().replaceAll("[,=:\"]+", "");
			ObjectName pattern = new ObjectName("com.oracle.jdbc:type=diagnosability,name=" + loader);
			ObjectName diag = ((ObjectName[]) (mbs.queryNames(pattern, null).toArray(new ObjectName[0])))[0];
			mbs.setAttribute(diag, new Attribute("LoggingEnabled", true));
			System.out.println("LoggingEnabled = " + mbs.getAttribute(diag, "LoggingEnabled"));
			

     如果用的是Oracle 10g,直接执行：

/**oracle 10g 启动方法*/
			oracle.jdbc.driver.OracleLog.setTrace(true); // enable logging
			oracle.jdbc.driver.OracleLog.setTrace(false); // disable logging

3.配置log文件

jdbc使用的是java.util.logging包中的Logger对象打印log。

	/**配置log文件*/
			Handler fh = new FileHandler("./oracle_jdbc_log.log");
			fh.setLevel(Level.ALL);
			fh.setFormatter(new SimpleFormatter());
			Logger.getLogger("").addHandler(fh);
			Logger.getLogger("").setLevel(Level.ALL);

4.下面给大家一个完成的Demo

import javax.management.Attribute;
import javax.management.AttributeNotFoundException;
import javax.management.InstanceNotFoundException;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanException;
import javax.management.MBeanServer;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.ReflectionException;

public void run() throws SQLException {
		DriverManager.registerDriver(new OracleDriver());
		//需在加载OracleDriver之后开启log
		enableOracleLogging();
		Connection conn = null;
		Statement stmt = null;
		ResultSet rset = null;
		try {
			conn = getConnection();
			System.out.println("Connection retrieved..");
			stmt = conn.createStatement();
			rset = stmt.executeQuery("select empno from emp");
			while (rset.next()) {
				System.out.println(rset.getInt(1));
			}
		} catch (SQLException sqle) {
			sqle.printStackTrace();
		} finally {
			if (rset != null) {
				rset.close();
			}
			if (stmt != null) {
				stmt.close();
			}
			if (conn != null) {
				conn.close();
			}
		}
	}
public static void enableOracleLogging() {
		try {
			/** 配置log文件 */
			Handler fh = new FileHandler("./oracle_jdbc_log.log");
			fh.setLevel(Level.ALL);
			fh.setFormatter(new SimpleFormatter());
			Logger.getLogger("").addHandler(fh);
			Logger.getLogger("").setLevel(Level.ALL);
			/** oracle 11g 启动方法 */
			MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
			String loader = Thread.currentThread().getContextClassLoader().toString().replaceAll("[,=:\"]+", "");
			ObjectName pattern = new ObjectName("com.oracle.jdbc:type=diagnosability,name=" + loader);
			ObjectName diag = ((ObjectName[]) (mbs.queryNames(pattern, null).toArray(new ObjectName[0])))[0];
			mbs.setAttribute(diag, new Attribute("LoggingEnabled", true));
			System.out.println("LoggingEnabled = " + mbs.getAttribute(diag, "LoggingEnabled"));
			/** oracle 10g 启动方法 */
			// oracle.jdbc.driver.OracleLog.setTrace(true); // enable logging
			// oracle.jdbc.driver.OracleLog.setTrace(false); // disable logging

		} catch (Exception e) {
			e.printStackTrace();
		}
	}