Question

我在eclipse中写了个简单的java连接mysql数据库的程序，总连不上，求指导！

import java.sql.*;

public class JdbcSql {
public static void main(String args[]) throws Exception{
String Driver="com.mysql.jdbc.Driver" ; //驱动程序
String URL="jdbc:mysql://localhost:3306/forjava" ; //连接的URL,db_name为数据库名
String Username="***" ; //用户名
String Password="***" ; //密码
Class.forName(Driver);
Connection con=DriverManager.getConnection(URL,Username,Password);
}
}

我有导入mysql-connector-java-5.1.18-bin.jar

报错为：

Exception in thread "main" java.sql.SQLException: Access denied for user 'MySQL'@'localhost' (using password: YES)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1073)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3609)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3541)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:943)
at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:4113)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1308)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2336)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
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:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at JdbcSql.main(JdbcSql.java:10)

Answer 1

这个问题，我有经验。程序没有错的情况下。
先停止mysql服务，然后打开命令行。输入mysqld_safe --skip-grant-tables
然后输入 mysql -u root
然后修改密码update user set Password = PASSWORD('新密码') where User ='root';
当然，密码也可以不改
然后flus privileges接着quit退出
然后重启mysql。
搞定

追问

貌似我在命令行里输哪些东西都没反应，
我进了mysql界面 输了密码后再输其他的东西都没用了 连quit都没反应
还有就是 程序里的user 和 password 是不是装mysql是设置的啊？我记得都没错啊
不知怎么就是连不上。。。

Answer 2

我对这个也不是很熟悉，我从网上找的一个，我用了连接成功！你可以参考下。
import java.sql.*;

public class DB {
public static Connection getConn() {
Connection conn = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/zhaoshu?useUnicode=true&characterEncoding=UTF-8&user=root&password=");

} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}

return conn;
}

public static PreparedStatement prepare(Connection conn, String sql) {
PreparedStatement pstmt = null;
try {
if(conn != null) {
pstmt = conn.prepareStatement(sql);
}
} catch (SQLException e) {
e.printStackTrace();
}
return pstmt;
}

public static PreparedStatement prepare(Connection conn, String sql, int autoGenereatedKeys) {
PreparedStatement pstmt = null;
try {
if(conn != null) {
pstmt = conn.prepareStatement(sql, autoGenereatedKeys);
}
} catch (SQLException e) {
e.printStackTrace();
}
return pstmt;
}

public static Statement getStatement(Connection conn) {
Statement stmt = null;
try {
if(conn != null) {
stmt = conn.createStatement();
}
} catch (SQLException e) {
e.printStackTrace();
}
return stmt;
}

Answer 3

package com.geo.common;

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

public class MobileBankDao {
private Connection conn = null;

private Statement st = null;

private String url="localhost";

private String port="3306";

private String user = "root";

private String password = "root";

private String sDBDriver = "org.gjt.mm.mysql.Driver";

private String db="mobilebank";

public MobileBankDao() {

try {
Class.forName(sDBDriver);
getConnection();
} catch (java.lang.ClassNotFoundException e) {
System.err.println("lib下驱动包未安装");
}
}

// 创建连接
private void getConnection() {
// 采用gb2312字符集
String sConnStr = "jdbc:mysql://"+url+":"+port+"/"+db+"?useServerPrepStmts=false&useUnicode=true&characterEncoding=gb2312";
System.out.println(sConnStr);

try {
conn = DriverManager.getConnection(sConnStr, user, password);
} catch (SQLException ex) {
System.err.println("connect对象建立错误!");
}
}

Answer 4

你这是什么意思啊，
链接数据库其实很简单具体代码如下：
package db;
import java.sql.*;

public class DB {
private Connection con=null;
private Statement stmt=null;
private ResultSet rs=null;
public DB(){}
public Connection getConnection(){
String url="jdbc:mysql://127.0.0.1:3306/test?useUnicode=true

Answer 5

你的密码是不是输错了，它说用现在的密码访问被拒