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  • DBUtils使用(对jdbc的封装)

    package com.mysql.demo;
    
    import java.sql.SQLException;
    import java.util.Iterator;
    import java.util.List;
    
    import org.apache.commons.dbutils.QueryRunner;
    import org.apache.commons.dbutils.handlers.BeanHandler;
    import org.apache.commons.dbutils.handlers.BeanListHandler;
    import org.junit.Test;
    
    import com.mysql.bean.user;
    
    //增删改查
    //用QueryRunner接口和ResultSetHandler
    //增删改:1:queryRunner()方法获取数据流连接池的连接,2:在执行queryRunner提供的update()方法
    //查询方法:1:queryRunner()获取连接。2:调用queryRunner的query()方法。在对结果集Handler,把数据封装为一个list集合
    public class dbutil {
    
    //使用dbutil完成数据库的crud
    @Test
    public void insert() throws SQLException
    {
    //获取数据库连接池操作数据库
    QueryRunner run=new QueryRunner(sqlpooling.getDataSource());
    String sql="insert into login values(?,?)";
    Object params[]={"keke","keke"};
    run.update(sql, params);
    }
    @Test
    public void update() throws SQLException
    {
    //获取数据库连接池操作数据库
    QueryRunner run=new QueryRunner(sqlpooling.getDataSource());
    String sql="update login set password=? where username=?";
    Object params[]={"789","keke"};
    run.update(sql, params);
    }
    
    @Test
    public void delete() throws SQLException
    {
    //获取数据库连接池操作数据库
    QueryRunner run=new QueryRunner(sqlpooling.getDataSource());
    String sql="delete from login where username=?";
    //只有一个参数没必要准备参数数组了
    run.update(sql, "simant");
    }
    @Test
    public void find() throws SQLException
    {
    //获取数据库连接池操作数据库
    QueryRunner run=new QueryRunner(sqlpooling.getDataSource());
    String sql="select username,password from login where username=?";
    user u=(user) run.query(sql,"keke",new BeanHandler(user.class));//把结果集处理到那个bean中去,创建userbean,这边省略
    System.out.println(u.getPassword());
    
    }
    @Test
    public void findAll() throws SQLException
    {
    //获取数据库连接池操作数据库
    QueryRunner run=new QueryRunner(sqlpooling.getDataSource());
    String sql="select * from login";
    List uu=(List) run.query(sql,new BeanListHandler(user.class));
    //多条记录的话用beanlistHandler处理到一个集合中去
    Iterator<user> it=uu.iterator();
    while(it.hasNext())
    {
    user u=it.next();
    System.out.println(u.getUsername());
    System.out.println(u.getPassword());
    }
    
    }
    @Test
    public void batch() throws SQLException//批量处理的话要插入多条记录,用二维数组
    {
    //获取数据库连接池操作数据库
    QueryRunner run=new QueryRunner(sqlpooling.getDataSource());
    String sql="insert into login values(?,?)";
    Object param[][]=new Object[3][2];//大小为3的数组,大小为3的数组里面又是大小为2的数组
    for(int i=0;i<param.length;i++)
    {
    param[i]=new Object[]{"name"+i,"password"+i};
    }
    run.batch(sql, param);
    
    }
    }
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  • 原文地址:https://www.cnblogs.com/linhong/p/4392887.html
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