java-mysql

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

0. install mysql , and change the root password to root
1. download jdbc from mysql connector. or use this attachment.
2. tar -zxvf mysql-connector-java-5.1.23.tar.gz /usr/localcll
3. # export CLASSPATH=/usr/local/mysql-connector-java-5.1.23/mysql-connector-java-5.1.23-bin.jar:$CLASSPATH
4. vi getmySQLConnection.java   // Try a simple //

import java.sql.*;
public class getmySQLConnection
{
        public static void main(String[] args)
        {
                DB db = new DB();
                Connection conn=db.dbConnect(
                  "jdbc:mysql://localhost:3306/test", "root", "root");
        }

}

class DB
{
        public DB() {}

        public Connection dbConnect(String db_connect_string,
          String db_userid, String db_password)
        {
                try
                {
                        Class.forName("com.mysql.jdbc.Driver").newInstance();
                        Connection conn = DriverManager.getConnection(
                          db_connect_string, db_userid, db_password);
     
                        System.out.println("connected");
                        return conn;
                       
                }
                catch (Exception e)
                {
                        e.printStackTrace();
                        return null;
                }
        }
}

5. javac getmySQLConnection.java
6. java getmySQLConnection
7. A dbcmysql Engineer




dbcmysql.java
//package db;


import java.sql.*;
public class jdbcmysql {
private Connection con = null; //Database objects
private Statement stat = null;
private ResultSet rs = null;
private PreparedStatement pst = null;

private String dropdbSQL = "DROP TABLE User ";

  private String createdbSQL = "CREATE TABLE User (" +
    "    id     INTEGER " +
    "  , name    VARCHAR(20) " +
    "  , passwd  VARCHAR(20))";

  private String insertdbSQL = "insert into User(id,name,passwd) " +
      "select ifNULL(max(id),0)+1,?,? FROM User";

  private String selectSQL = "select * from User ";

  public jdbcmysql()  // java-mysql-connect
  {
    try {
      Class.forName("com.mysql.jdbc.Driver");
      con = DriverManager.getConnection(
      "jdbc:mysql://localhost/test?useUnicode=true&characterEncoding=utf-8",
      "root","root");
    }
    catch(ClassNotFoundException e)
    {
      System.out.println("DriverClassNotFound :"+e.toString());
    }
    catch(SQLException x) {
      System.out.println("Exception :"+x.toString());
    }
  }



  public void createTable()  // java-mysql-create
  {
    try
    {
      stat = con.createStatement();
      stat.executeUpdate(createdbSQL);
    }
    catch(SQLException e)
    {
      System.out.println("CreateDB Exception :" + e.toString());
    }
    finally
    {
      Close();
    }
  }
  public void insertTable( String name,String passwd)
  {
    try
    {
      pst = con.prepareStatement(insertdbSQL);
    
      pst.setString(1, name);
      pst.setString(2, passwd);
      pst.executeUpdate();
    }
    catch(SQLException e)
    {
      System.out.println("InsertDB Exception :" + e.toString());
    }
    finally
    {
      Close();
    }
  }

  public void dropTable()  // java-mysql-drop
  {
    try
    {
      stat = con.createStatement();
      stat.executeUpdate(dropdbSQL);
    }
    catch(SQLException e)
    {
      System.out.println("DropDB Exception :" + e.toString());
    }
    finally
    {
      Close();
    }
  }

  public void SelectTable() // java-mysql-select
  {
    try
    {
      stat = con.createStatement();
      rs = stat.executeQuery(selectSQL);
      System.out.println("ID\t\tName\t\tPASSWORD");
      while(rs.next())
      {
        System.out.println(rs.getInt("id")+"\t\t"+
            rs.getString("name")+"\t\t"+rs.getString("passwd"));
      }
    }
    catch(SQLException e)
    {
      System.out.println("DropDB Exception :" + e.toString());
    }
    finally
    {
      Close();
    }
  }

  private void Close() java-mysql-close
  {
    try
    {
      if(rs!=null)
      {
        rs.close();
        rs = null;
      }
      if(stat!=null)
      {
        stat.close();
        stat = null;
      }
      if(pst!=null)
      {
        pst.close();
        pst = null;
      }
    }
    catch(SQLException e)
    {
      System.out.println("Close Exception :" + e.toString());
    }
  }


  public static void main(String[] args)
  {
    jdbcmysql test = new jdbcmysql();
    test.dropTable();
    test.createTable();
    test.insertTable("yku", "12356");
    test.insertTable("yku2", "7890");
    test.SelectTable();
  }
}