请教JAVA如何连接MYSQL的问题

Question

网上差了点资料，按照说明照着做了，JSP运行没问题，但是运行JAVA程序的话就问题来了

Answer 1

package pag;
import java.sql.*;
public class conn{
String driverName="com.mysql.jdbc.Driver";
String connect="jdbc:mysql://localhost/fdb_product?user=root";
String userName="root";
String password="";
Connection con=null;
ResultSet rs=null;
public void con(){
try{
Class.forName(driverName);
}catch(java.lang.ClassNotFoundException e){
System.err.println(e.getMessage());
}
}

public ResultSet executeQuery(String sql){
try{
con=DriverManager.getConnection(connect);
Statement stmt=con.createStatement();
rs=stmt.executeQuery(sql);
}catch(SQLException ex){
System.err.println(ex.getMessage());
}
return rs;
}
}

Answer 2

String connect="jdbc:mysql://localhost/fdb_product?user=root";
????
------------------------------------------------------------------
String userName="root";
String password="";
------------------------------------------------------------------
看出来了吧

Answer 3

com.mysql.jdbc.Driver是不合法的驱动
 PoemCode(诗意代码之魔数)所说的是正确的，我在JSP里面已经可以完成。但是在JAVA程序里面就会报没有找到合适的驱动。这是为什么？我在CLASSPATH里面已经将mysql-connector-java-3.1.12加进去了。

Answer 4

/*
 * SQLController.java
 *
 * Created on 2006年1月16日, 下午1:33
 */package sqlmvc;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Vector;/**
 *
 * @author poco
 */
public class SQLController {
    
    /** Creates a new instance of SQLController */
    public SQLController() {
    }
    
    public Connection con;
    
    public DriverManager driver;
    
    public Statement state;
    
    public Connection getCon() {
        if(con == null){
            try {
                Class.forName("com.mysql.jdbc.Driver");
                System.out.println("load the driver");
                con = DriverManager.getConnection("jdbc:mysql://localhost/MVC?user=poemcode&password=aaaa&useUnicode=true&characterEncoding=UTF-8");
                System.out.println("try to get Connetion");
                if(con == null)
                    System.out.println("failed to get Connection.");
                else
                    System.out.println("get Conection");
            } catch (ClassNotFoundException ex) {
                System.err.println("Can't find the driver of MySql");
                ex.printStackTrace();
            } catch (SQLException ex) {
                System.out.println("SQLState: " + ex.getSQLState() + " ErrorCode: " + ex.getErrorCode());
                ex.printStackTrace();
            }
        }
        return con;
    }
    
    public Vector cache;
    
    public int colCount;
    
    public String[] headers;
    
    public void doQuery(String info) {
        cache = new Vector();
        try {
            state = getCon().createStatement();
            System.out.println("create Statement");
            result = state.executeQuery(info);
            System.out.println("get ResultSet");
            if(state.execute(info)){
                result = state.getResultSet();
                rsmd = result.getMetaData();
                colCount = rsmd.getColumnCount();
                headers = new String[colCount];
                for(int t = 1; t <= colCount; t++)
                    headers[t-1] = rsmd.getColumnName(t);
                while(result.next()){
                    String record[] = new String[colCount];
                    for(int i = 0; i < colCount; i++)
                        record[i] = result.getString(i+1);
                    cache.addElement(record);
                }
                //fireTableChanged(null);
            }
        } catch (SQLException ex) {
            System.out.println("Can't create Statement.");
            System.err.println("SQLState: " + ex.getSQLState() + " ErrorCode: " + ex.getErrorCode());
            ex.printStackTrace();
        }finally {
            if (result != null) {
                try {
                    result.close();
                    System.out.println("ResultSet close.");
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                }
                
                result = null;
            }
            
            if (state != null) {
                try {
                    state.close();
                    System.out.println("Statement close.");
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                }
                
                state = null;
            }
        }
    }
    
    public ResultSet result;
    
    public ResultSetMetaData rsmd;    public void doDelete(String info) {
        try {
            state = getCon().createStatement();
            System.out.println("create Statement.");
            state.execute(info);
            System.out.println("delete the info.");        } catch (SQLException ex) {
            System.out.println("Can't create Statement.");
            System.err.println("SQLState: " + ex.getSQLState() + " ErrorCode: " + ex.getErrorCode());
            ex.printStackTrace();
        }finally {
            if (result != null) {
                try {
                    result.close();
                    System.out.println("ResultSet close.");
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                }
                
                result = null;
            }
            
            if (state != null) {
                try {
                    state.close();
                    System.out.println("Statement close.");
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                }
                
                state = null;
            }
        }
    }    public void doInsert(String info) {
         try {
            state = getCon().createStatement();
            System.out.println("create Statement.");
            state.execute(info);
            System.out.println("insert the info.");        } catch (SQLException ex) {
            System.out.println("Can't create Statement.");
            System.err.println("SQLState: " + ex.getSQLState() + " ErrorCode: " + ex.getErrorCode());
            ex.printStackTrace();
        }finally {
            if (result != null) {
                try {
                    result.close();
                    System.out.println("ResultSet close.");
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                }
                
                result = null;
            }
            
            if (state != null) {
                try {
                    state.close();
                    System.out.println("Statement close.");
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                }
                
                state = null;
            }
        }
    }    public void doUpdate(String info) {
        try {
            state = getCon().createStatement();
            System.out.println("create Statement.");
            state.execute(info);
            System.out.println("insert the info.");        } catch (SQLException ex) {
            System.out.println("Can't create Statement.");
            System.err.println("SQLState: " + ex.getSQLState() + " ErrorCode: " + ex.getErrorCode());
            ex.printStackTrace();
        }finally {
            if (result != null) {
                try {
                    result.close();
                    System.out.println("ResultSet close.");
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                }
                
                result = null;
            }
            
            if (state != null) {
                try {
                    state.close();
                    System.out.println("Statement close.");
                } catch (SQLException sqlEx) {
                    sqlEx.printStackTrace();
                }
                
                state = null;
            }
        }
    }
    
}

Answer 5

String connect="jdbc:mysql://localhost/fdb_product?user=root";
String userName="root";
String password="";
------------------------------------------------------------------
String connect="jdbc:mysql://localhost/fdb_product";
String userName="root";
String password="";我第一次回贴的时候发现你重复了user，因此我问你看明白没有（误会了你的意思）
Connection con = Drivermanager.getConnection(connect,userName,password);
或者形如我的例子中所采用形式：
con=DriverManager.getConnection("jdbc:mysql://localhost/MVC?user=poemcode&password=aaaa");
注：这里MVC是数据库名称，用户名为poemcode，密码为aaaa。此例为我在上学期课程设计中的代码，测试通过。
在你的回贴中“我在CLASSPATH里面已经将mysql-connector-java-3.1.12加进去了。”，真正的应该是把mysql-connector-java-3.1.12-bin.jar加入进去。