java死锁模拟

package cn.tk.netcore.rest;

import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.sql.*;

@SpringBootTest
@RunWith(SpringRunner.class)
@Slf4j
public class JDBCExample {
    //第二步：说明JDBC驱动的名称和数据库的地址
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://ip:port/tktop";

    //第三步：说明数据库的认证账户及密码
    static final String USER = "user";
    static final String PASS = "password";

    @Test
    public  void jsbcTest() {
        //第四步：注册JDBC驱动
        try {
            Class.forName(JDBC_DRIVER);
        } catch (ClassNotFoundException e) {
            //这里会发生类没有找到的异常！
            e.printStackTrace();
        }
        //第五步：获得数据库连接
        try {
            Connection connection =  DriverManager.getConnection(DB_URL,USER,PASS);
            //设置手动提交
            connection.setAutoCommit (false);

            Statement statement = connection.createStatement();
            //第六步：执行修改语句
            String sql = "UPDATE s_policymain s set s.scheme_id = '1' where s.policy_no = '123781628736178321'";
            statement.executeUpdate (sql);

            //第七步：执行修改语句
            String sql1 = "UPDATE s_policymain s set s.scheme_id = '2' where s.policy_no = '200323008677720117840'";
            statement.executeUpdate(sql1);


            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
            //这里会发生SQL异常，因为我们提供的的账户和密码不一定能连接成功
        }
    }
}

package cn.tk.netcore.rest;

import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.sql.*;

@SpringBootTest
@RunWith(SpringRunner.class)
@Slf4j
public class JDBCExample1{
    //第二步：说明JDBC驱动的名称和数据库的地址
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://ip:port/tktop";

    //第三步：说明数据库的认证账户及密码
    static final String USER = "user";
    static final String PASS = "password";

    @Test
    public  void jsbcTest() {
        //第四步：注册JDBC驱动
        try {
            Class.forName(JDBC_DRIVER);
        } catch (ClassNotFoundException e) {
            //这里会发生类没有找到的异常！
            e.printStackTrace();
        }
        //第五步：获得数据库连接
        try {
            Connection connection =  DriverManager.getConnection(DB_URL,USER,PASS);
            //设置手动提交
            connection.setAutoCommit (false);

            Statement statement = connection.createStatement();
            //第六步：执行修改语句
            String sql1 = "UPDATE s_policymain s set s.scheme_id = '2' where s.policy_no = '200323008677720117840'";
            statement.executeUpdate (sql1);

            //第七步：执行修改语句
            String sql = "UPDATE s_policymain s set s.scheme_id = '1' where s.policy_no = '123781628736178321'";
            statement.executeUpdate(sql);


            //第七步：关闭连接资源
            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
            //这里会发生SQL异常，因为我们提供的的账户和密码不一定能连接成功
        }
    }
}

执行步骤：

1，执行 JDBCExample的第六步，

2，执行JDBCExample1的第六步，

3，执行 JDBCExample的第七步，

4，执行 JDBCExample1的第七步，

报出死锁异常：

com.mysql.jdbc.exceptions.jdbc4.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:952)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3933)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3869)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2524)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2675)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2465)
at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1536)
at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2585)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1464)
at cn.tk.netcore.rest.JDBCExample1.jsbcTest(JDBCExample1.java:45)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:74)
at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:84)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)