dbtester3.java

《java网络编程精解》的源代码

import java.sql.*;
public class DBTester3{
  private ConnectionProvider provider;
  private Connection con;
  private PreparedStatement addStmt;
  private PreparedStatement deleteStmt;
  private PreparedStatement findStmt;

  public DBTester3(ConnectionProvider provider)throws SQLException{
    this.provider=provider;
    con=provider.getConnection();
  }
  public void addCustomer(String name,int age,String address) throws SQLException{
    String sql="insert into CUSTOMERS(NAME,AGE,ADDRESS) values(?,?,?)";
    if(addStmt==null)
      addStmt=con.prepareStatement(sql);
    addStmt.setString(1,name);
    addStmt.setInt(2,age);
    addStmt.setString(3,address); 
    addStmt.execute();
 }
  
  public void deleteCustomer(String name) throws SQLException{
    String sql="delete from CUSTOMERS where NAME=?";
    if(deleteStmt==null)
      deleteStmt=con.prepareStatement(sql);
    deleteStmt.setString(1,name);
    deleteStmt.execute();
  }

  public void findCustomer(String name,int age) throws SQLException{
    String sql = " select ID,NAME,AGE,ADDRESS from CUSTOMERS where NAME=? and AGE=?";
    if(findStmt==null)
      findStmt=con.prepareStatement(sql);
    findStmt.setString(1, name); 
    findStmt.setInt(2,age); 
    //查询记录
    ResultSet rs= findStmt.executeQuery();
    try{
      //输出查询结果
      while (rs.next()){
        long id = rs.getLong(1);
        name = rs.getString(2);
        age = rs.getInt(3);
        String address = rs.getString(4);
        
        //打印所显示的数据
        System.out.println("id="+id+",name="+name+",age="+age+",address="+address);
      }
    }finally{
      rs.close();
    }
  }

  public void close(){
    try{
      con.close();
    }catch(SQLException e){e.printStackTrace();} 
  }
  public static void main(String args[])throws Exception{
    DBTester3 tester=new DBTester3(new ConnectionProvider()); 
    tester.addCustomer("小王",20,"上海");
    tester.addCustomer("小玲",30,"上海"); 
    tester.findCustomer("小王",20);
    tester.findCustomer("小玲",30);
    tester.deleteCustomer("小王");
    tester.deleteCustomer("小玲");
    
    tester.close();
  }
}


/****************************************************
 * 作者：孙卫琴                                     *
 * 来源：<<Java网络编程精解>>                       *
 * 技术支持网址：www.javathinker.org                *
 ***************************************************/