commons-DBUtils使用方式简介 2

SQL Java MySQL JDBC Bean 

1.使用commons DButils组件对数据库进行查询。
首先使用数据源以及本组件进行数据库的链接，建立QueryRunner类型的对象。
使用数组，对sql语句中的占位符进行填充。
建立MapListHandler类型对象，用于装载每一条记录。
全部的记录都以List形式返回，使用代码中所示结果，对记录进行读取。

public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.print("Test AND I am so BORING!<br>");
  request.setCharacterEncoding("utf-8");
  Context context;
  try {
   context = new InitialContext();
   DataSource ds=(DataSource)context.lookup("java:/comp/env/jdbc/oracleds");
   QueryRunner qr=new QueryRunner(ds);
//   String sql="select * from users";
   String sql="select * from users where id=? and name=?";

   MapListHandler handler=new MapListHandler();
   String [] param={"2","meng"};
//   List list=(List)qr.query(sql,handler);
   List list=(List)qr.query(sql,param,handler);

   for(int i=0;i<list.size();i++){
    Map map=(Map)list.get(i);
    out.println(map.get("id"));
    out.println(map.get("name"));
    out.print("<br>");
   }

  } catch (NamingException e) {
     // TODO Auto-generated catch block
      e.printStackTrace();
  } catch (SQLException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
  }
    out.flush();
    out.close();
 }

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.print("Test AND I am so BORING!<br>");
  request.setCharacterEncoding("utf-8");
  Context context;
  try {
   context = new InitialContext();
   DataSource ds=(DataSource)context.lookup("java:/comp/env/jdbc/oracleds");
   QueryRunner qr=new QueryRunner(ds);
//   String sql="select * from users";
   String sql="select * from users where id=? and name=?";
   
   MapListHandler handler=new MapListHandler();
   String [] param={"2","meng"};
//   List list=(List)qr.query(sql,handler);
   List list=(List)qr.query(sql,param,handler);
   
   for(int i=0;i<list.size();i++){
    Map map=(Map)list.get(i);
    out.println(map.get("id"));
    out.println(map.get("name"));
    out.print("<br>");
   }
   
  } catch (NamingException e) {
     // TODO Auto-generated catch block
      e.printStackTrace();
  } catch (SQLException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
  }
    out.flush();
    out.close();
 }

}

2.使用本组件对数据库进行数据管理。包括“增删改”。
最开始同样，对数据库进行链接，而后建立QueryRunner类型的对象，因为对数据的管理不返回一个结果集，因此只返回一个int类型的变量。
同样使用数组对sql语句中的占位符进行填充。
最后根据返回的值的大小（和0比），来肯定是否成功执行本语句。

public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {

  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("Test Again!");
  String sql="insert into users values(?,?) ";
  Context context;
  try {
   context = new InitialContext();

  DataSource ds=(DataSource)context.lookup("java:/comp/env/jdbc/oracleds");
  QueryRunner qr=new QueryRunner(ds);
//  MapListHandler handler=new MapListHandler();
  String [] params={"3","Zhang"};
  int i=qr.update(sql, params);
  if(i>0)
  {
   out.println("成功！");
  }
  else
  {
   out.println("Failed!");
  }
  } catch (NamingException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {

  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  out.println("Test Again!");
  String sql="insert into users values(?,?) ";
  Context context;
  try {
   context = new InitialContext();
  
  DataSource ds=(DataSource)context.lookup("java:/comp/env/jdbc/oracleds");
  QueryRunner qr=new QueryRunner(ds);
//  MapListHandler handler=new MapListHandler();
  String [] params={"3","Zhang"};
  int i=qr.update(sql, params);
  if(i>0)
  {
   out.println("成功！");
  }
  else
  {
   out.println("Failed!");
  }
  } catch (NamingException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

别外加:

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.DriverManager;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

public class dbtest
{

    infoBean bean = new infoBean();

    BeanListHandler h = new BeanListHandler(bean.getClass());
    Connection connect = null;
    List result = new ArrayList();

    try
    {
      Class.forName("com.mysql.jdbc.Driver");
      connect = DriverManager.getConnection(
          "jdbc:mysql://localhost/normaltest", "root", "root");


      QueryRunner run = new QueryRunner();

      result = (ArrayList) run.query(connect,
          "SELECT username,age,money,usertime FROM info", h);
    } catch (Exception e)
    {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }

    return result;
  }