Question

我安装了 MYSQLSERVER 5.1 。然后我安装了mysql-connector-java-3.0.8-stable-bin.jar并将驱动器c放入文件夹核心C：\ core.Then在计算机属性中，我创建了变量名为CLASSPATH和变量值的用户变量：C：\ core \ mysql-connector-java-3.0.8-stable-bin.jar。

现在我创建了数据库EMPLOYEE4 MY JAVA代码IS：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;
class MySQLTest{


    public static void main(String[] args) {  
        try {  
            Class.forName("com.mysql.jdbc.Driver");  
            Connection dbCon = DriverManager.getConnection(  
                    "jdbc:mysql://localhost:3306/EMPLOYEE4", "root", "root");  

        String query ="select count(*) from EMPLOYEE4 ";

        Statement stmt = null;
        ResultSet rs = null;

            //getting PreparedStatment to execute query
            stmt = dbCon.prepareStatement(query);

            //Resultset returned by query
            rs = stmt.executeQuery(query);

            while(rs.next()){
             int count = rs.getInt(1);
             System.out.println("count of stock : " + count);
            }

        } catch (Exception ex) {
             ex.printStackTrace();
            //Logger.getLogger(CollectionTest.class.getName()).log(Level.SEVERE, null, ex);
        } finally{
           //close connection ,stmt and resultset here
        }

    }  
   }

我收到错误

SQL Connection exceptionjava.sql.SQLException: Communication link failure: java.
io.IOException, underlying cause: Unexpected end of input stream

** BEGIN NESTED EXCEPTION **

java.io.IOException
MESSAGE: Unexpected end of input stream

STACKTRACE:

java.io.IOException: Unexpected end of input stream
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:339 )
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:78 2)
at com.mysql.jdbc.Connection.createNewIO(Connection.j ava:1585)
at com.mysql.jdbc.Connection.<init>(Connection.java:5 24)
at com.mysql.jdbc.Driver.connect(Driver.java:359)
at java.sql.DriverManager.getConnection(DriverManager .java:512)
at java.sql.DriverManager.getConnection(DriverManager .java:193)
at DbHelper.getConnection(DbHelper.java:34)
at DbHelper.main(DbHelper.java:466)


** END NESTED EXCEPTION **

Answer 1

此：

java.io.IOException: Unexpected end of input stream
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:339 )
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:78 2)

表示您正在通过classpath ok获取JDBC驱动程序（请参阅完全限定的包名称）。您无法连接到您的数据库，我怀疑您的MySQL数据库没有运行，或者没有配置为接受该端口上的连接。

你能连接到那个端口吗？（通过简单的telnet）或使用netstat确认某些内容正在侦听该端口？

如何连接MYSQL和java

1 个答案: