不知道为啥一直报错，不能运行

package com.imooc.jdbc.demo1;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.junit.jupiter.api.Test;

import com.mysql.cj.jdbc.Driver;

//import com.mysql.jdbc.Driver;

public class JDBCDemo1 {

	@Test
	public void demo1() {
		//1.加载驱动
		try {
			//1.加载驱动
			DriverManager.registerDriver(new Driver());
			//2.获得链接
			Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/jdbctest"+"?useSSL=false&server Timezone=Hongkong&useUnicode=true&characterEncoding=utf-8","root","root");
			//3.创建执行SQL语句的对象，并执行SQL
			//3.1创建执行SQL语句的对象
			String sql = "select * from user";
			Statement stmt = conn.createStatement();
			//3.2执行sql
			ResultSet resultSet = stmt.executeQuery(sql);
			while(resultSet.next()) {
				int uid = resultSet.getInt("uid");
				String username = resultSet.getString("username");
				String password = resultSet.getString("password");
				String name = resultSet.getString("name");
				
				System.out.println(uid + "   " + name + "   " + username + "   " + password);
			}
			//4.释放资源
			resultSet.close();
			stmt.close();
			conn.close();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
}

detachment86 2019-04-28

源自：JDBC入门 2-1 JDBC的入门

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2回答

好帮手慕阿满回答被采纳获得+3积分 2019-04-28 18:42:53

同学你好，建议同学使用cmd链接一下数据库看是否能够链接上，如果不可以，可能是数据的服务没有启动，建议同学先去启动mysql服务。邮件点击我的电脑，然后选择管理，出现如下界面，

选择服务，找到mysql，然后启动服务。如上所示，我的mysql处于启动状态。

建议同学启动mysql服务后再试试。

如果我的回答解决了你的疑惑，请采纳。祝：学习愉快~

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detachment86 提问者 #1

我的mysql处于启动状态还是会报错 java.sql.SQLException: The server time zone value '???ú±ê×??±??' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.

2019-04-28 19:34:24

提问者 detachment86 2019-04-28 17:52:40

把老师的项目导入也会报同样的错误

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3515)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3447)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:911)

at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3953)

at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1276)

at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2048)

at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:723)

at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)

at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)

at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)

at java.sql.DriverManager.getConnection(Unknown Source)

at com.imooc.jdbc.demo1.JDBCDemo1.demo1(JDBCDemo1.java:89)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

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.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)

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)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)

at org.junit.runners.ParentRunner.run(ParentRunner.java:363)

at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)

at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)