数据库连接不上,写了个简单的测试方法,结果报错
package com.bdrj.util;import java.sql.*;public class a123 { public static void main(String[] args){
Connection con = null;
try{
//1、加载驱动
String driverName =
"com.mysql.jdbc.Driver";
Class.forName(driverName);
//2、建立数据库连接
String url =
"jdbc:mysql//localhost:3306/wmdw";
String username = "root";
String pwd = "lly";
con = DriverManager.getConnection(
url,username,pwd);
System.out.println("con->"+con); }catch(Exception e){
e.printStackTrace();
}finally{
try{
con.close();
}catch(Exception e1){
e1.printStackTrace();
}
}
}
}
异常
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.bdrj.util.a123.main(a123.java:19)
java.lang.NullPointerException
at com.bdrj.util.a123.main(a123.java:27)申明我已经把mysql的jar包导入了,以前这个包还用得好好的,真是郁闷到了极点
package com.bdrj.util;import java.sql.*;public class a123 { public static void main(String[] args){
Connection con = null;
try{
//1、加载驱动
String driverName =
"com.mysql.jdbc.Driver";
Class.forName(driverName);
//2、建立数据库连接
String url =
"jdbc:mysql//localhost:3306/wmdw";
String username = "root";
String pwd = "lly";
con = DriverManager.getConnection(
url,username,pwd);
System.out.println("con->"+con); }catch(Exception e){
e.printStackTrace();
}finally{
try{
con.close();
}catch(Exception e1){
e1.printStackTrace();
}
}
}
}
异常
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.bdrj.util.a123.main(a123.java:19)
java.lang.NullPointerException
at com.bdrj.util.a123.main(a123.java:27)申明我已经把mysql的jar包导入了,以前这个包还用得好好的,真是郁闷到了极点
java -cp .;c:\mysql.jar com.bdrj.util.a1231 你在命令行里指定所有需要的jar
2 把jar加入到环境变量里面 CLASSPATH
"jdbc:mysql//localhost:3306/wmdw"; 改为String url =
"jdbc:mysql://localhost:3306/wmdw"; 你的结贴率好低啊,难怪没人回答!