jdbc 更新 测 并发

用到 junitperf-1.9.1.jar 这个包

用到 junit4

 

package com.bingfa;
import java.sql.Connection;

public final class JDBCUtils {
	private JDBCUtils() {
	}

	private static String url = "jdbc:mysql://localhost:3306/test";
	private static String user = "root";
	private static String password = "root";

	static {
		try {
			Class.forName("com.mysql.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			throw new ExceptionInInitializerError(e);
		}
	}

	public static Connection getConnection() throws SQLException {
		return DriverManager.getConnection(url, user, password);
	}

	public static void freePs(ResultSet rs, PreparedStatement ps, Connection conn) {
		try {
			if (rs != null)
				rs.close();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				if (ps != null)
					ps.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} finally {
				try {
					if (conn != null)
						conn.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}
	}
	
	
	public static void freeSt(ResultSet rs, Statement st, Connection conn) {
		try {
			if (rs != null)
				rs.close();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				if (st != null)
					st.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} finally {
				try {
					if (conn != null)
						conn.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}
	}
}

 

更新表，里面有用Statement和PreparedStatement两种方式

package com.bingfa;

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

public class UploadCC {
	

	public static void JDBCStatment() throws Exception {
		Connection conn = null;
		Statement st = null;
		ResultSet rs = null;
		try {
			conn = (Connection) JDBCUtils.getConnection();
			conn.setAutoCommit(false);
			
			String sql = "";
			sql = "SELECT cc FROM test WHERE id=1 ";
			st = conn.createStatement();
			rs = st.executeQuery(sql);
			int c = 0;
			while (rs.next()) {
				c = rs.getInt(1);
			}
			c = c + 1;
//用cc=cc+1，不会有并发问题，如果用c=c+1，则有问题
			sql = "UPDATE test SET cc = cc+1 WHERE id =1 ";
			st=(Statement) conn.createStatement();
			st.execute(sql);
			conn.commit();
			
		} finally {
			JDBCUtils.freeSt(rs, st, conn);
		}
	}
	
	
	
	public static void JDBCPrepare() throws Exception {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = (Connection) JDBCUtils.getConnection();
			conn.setAutoCommit(false);
			String sql = "";
			sql = "SELECT cc FROM test WHERE id=1 ";
			ps = conn.prepareStatement(sql);
			rs = ps.executeQuery();
			int c = 0;
			while (rs.next()) {
				c = rs.getInt(1);
			}
			c = c + 1;
			sql = "UPDATE test SET cc = ? WHERE id =1 ";
			ps = conn.prepareStatement(sql);
			ps.setInt(1, c);
			ps.execute();
			conn.commit();
		} finally {
			JDBCUtils.freePs(rs, ps, conn);
		}
	}

}

 

测试类，注意，测试并发并不用直接使用此类

package test;

import junit.framework.TestCase;

public class UploadCCTest extends TestCase {

	public UploadCCTest(String name) {
		super(name);
	}

	@org.junit.Test
	public void testJdbcStatment() {
		try {
			UploadCC.JDBCStatment();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	
	@org.junit.Test
	public void testJdbcPrepare() {
		try {
			UploadCC.JDBCPrepare();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}

 

 

用这个类进行并发测试

package test;

import com.clarkware.junitperf.LoadTest;
import com.clarkware.junitperf.TestMethodFactory;

import junit.framework.Test;

public class TestSuite {
	public static Test suite() {
		Test suite = new TestMethodFactory(UploadCCTest.class, "testJdbcStatment");
		Test loadTest = new LoadTest(suite, 20, 10);
//如果正常，cc的值应为200,但如果用c=c+1，值肯定小于200
		return loadTest;
	}
	
//	public static Test suite() {
//		Test suite = new TestMethodFactory(UploadCCTest.class, "testJdbcPrepare");
//		Test loadTest = new LoadTest(suite, 20, 10);
//		return loadTest;
//	}
}