日期:2014-05-20  浏览次数:20891 次

java连接MYSQL的问题,各位大牛们看看吧,小弟我疯了、、、

先说一说的,我的系统还有MYSQL的JDBC都已经配置好了、、、


系统变量:
CLSSPATH=D:\progarm two\mysql-connector-java-5.0.5\mysql-connector-java-5.0.5-bin.jar;C:\Program Files\Java\jdk1.6.0_12\bin;

用户变量为:
classpath=.;.;d:\PROGAR~2\JMF\lib\sound.jar;d:\PROGAR~2\JMF\lib\jmf.jar;d:\PROGAR~2\JMF\lib;%JAVA_HOME%\lib\tools.jar;%JAVA_HOME%\lib\dt.jar;.;%JAVA_HOME%\lib;%JAVA_HOME%\lib\tools.jar;D:\progarm two\mysql-connector-java-5.0.5\mysql-connector-java-5.0.5-bin.jar;

驱动的位置:
D:\progarm two\mysql-connector-java-5.0.5\mysql-connector-java-5.0.5.jar;

配置的ODBC:

Date Source Name :Mysql_Test
Databese:test


代码为:
PHP code

public class Main {
    public static void main(String[] args) {
         //驱动程序名
          String driver = "com.mysql.jdbc.Driver";

         //URL指向要访问的数据库名字:
          String url = "jdbc:mysql://localhost/Mysql_test";

          //Mysql配置用户名:
          String user = "root";
             
         //Mysql配置密码:
          String password = "LJZKID";

            try {
            //加载驱动程序
             Class.forName(driver);
            } catch (ClassNotFoundException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }
            
        try {

            //连接数据库
            Connection con = DriverManager.getConnection(url, user, password);

            if(!con.isClosed())
                 System.out.println("Succeeded connecting to the Database!");

            //statement用来执行SQL语言
            Statement st = con.createStatement();

            //要执行的SQL语言
            String sql = "select * from tablename";

            //结果集
            ResultSet rs =  (ResultSet)(Statement) st.executeQuery(sql);

            while( rs.next() ) {
                //选择col这列数据
                String name = rs.getString("col1");
                System.out.println("name=" +name );
            }
            rs.close();
            con.close();
        } catch (SQLException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }

    }

}









------解决方案--------------------
不清楚你现在是报什么错误,你把异常贴出来看看
从你代码import的东西也不太清楚,里面ResultSet rs = (ResultSet)(Statement) st.executeQuery(sql)是完全没有必要强制类型转换
直接ResultSet rs = st.executeQuery(sql)就OK的

你先把异常贴出来,然后import内容也贴出来再讨论吧
------解决方案--------------------
探讨
贴出log来
还有你的端口号怎么没有?例如String url="jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=gbk";

------解决方案--------------------
如以下odbc连接mysql的代码:

1.public static void main(String[] args)
2.{
3.Connection connection = null;
4.Statement statement;
5.ResultSet resultSet;
6.// 加载驱动程序以连接数据库
7.try
8.{
9.Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");//这个驱动不能是其他的..
10.connection = DriverManager.getConnection("jdbc:odbc:user","root","123"); //user是data Source ,root是用
11.
12.//户名,123是进入mysql的密码
13.System.out.println("open easy");
14.String query = "Select * from userrole";
15.statement = connection.createStatement();
16.resultSet = statement.executeQuery( query );
17.connection.close();
18.System.out.println("close easy");
19.
20.}
21.// 捕获加载驱动程序异常
22.catch ( ClassNotFoundException cnfex )
23.{
24.System.err.println(
25."装载 JDBC/ODBC 驱动程序失败。" );
26.cnfex.printStackTrace();