JavaWeb 使用DBUtils实现增删改查方式

目录

javaweb 使用dbutils实现增删改查

1、创建c3p0utils类

创建cn.itcast.jdbc.utils包

代码如下：

package cn.itcast.jdbc.utils;import javax.sql.datasource;import com.mchange.v2.c3p0.combopooleddatasource;public class c3p0utils {private static datasource ds;static {ds = new combopooleddatasource();}public static datasource getdatasource() {return ds;}}

2、创建dbutilsdao类

在src目录下，创建一个cn.itcast.jdbc.demo的包，在该包下创建一个dbutilsdao类

代码如下：

package cn.itcast.jdbc.demo;import java.sql.sqlexception;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 cn.itcast.chapter10.example.ur;import cn.itcast.jdbc.utils.c3p0utils;public class dbutilsdao {// 查询所有，返回list集合public list findall() throws sqlexception {// 创建queryrunner对象queryrunner runner = new queryrunner(c3p0utils.getdatasource());// 写sql语句string sql = "lect * from ur";// 调用方法list list = (list) runner.query(sql,                     new beanlisthandler(ur.class));return list;}// 查询单个，返回对象public ur find(int id) throws sqlexception {// 创建queryrunner对象queryrunner runner = new queryrunner(c3p0utils.getdatasource());// 写sql语句string sql = "lect * from ur where id=?";// 调用方法ur ur = (ur) runner.query(sql,                  new beanhandler(ur.class), new object[] { id });return ur;}// 添加用户的操作public boolean inrt(ur ur) throws sqlexception {// 创建queryrunner对象queryrunner runner = new queryrunner(c3p0utils.getdatasource());// 写sql语句string sql = "inrt into ur (name,password) values (?,?)";// 调用方法int笔记本没有声音 num = runner.update(sql,new object[] { ur.getname(), ur.getpassword() });if (num > 0)return true;return fal;}// 修改用户的操作public boolean update(ur ur) throws sqlexception {// 创建queryrunner对象queryrunner runner = new queryrunner(c3p0utils.getdatasource());// 写sql语句string sql = "update  ur t name=?,password=? where id=?";// 调用方法int num = runner.update(sql, new object[] { ur.getname(),                     ur.getpassword(),ur.getid() });if (num > 0)return true;return fal;}// 删除用户的操作public boolean delete(int id) throws sqlexception {// 创建queryrunner对象queryrunner runner = new queryrunner(c3p0utils.getdatasource());// 写sql语句string sql = "delete from ur where id=?";// 地球的直径是多少调用方法int num = runner.update(sql, id);if (num > 0)return true;return fal;}}

3、创建测试类

在cn.itcast.jdbc.demo包中创建测试类dbutilsdaotest类

代码如下：

package cn.itcast.jdbc.demo;import java.sql.sqlexception;import java.util.list;import cn.itcast.chapter10.example.ur;public class dbutilsdaotest1 {private static dbutilsdao dao = new dbutilsdao();public static void testinrt() throws sqlexception {ur ur = new ur();ur.tname("zhaoliu");ur.tpassword("666666");boole会呼吸的痛许嵩an b = dao.inrt(ur);system.out.println("testinrt:"+b);}public static void testupdate() throws sqlexception {ur ur = new ur();ur.tname("zhaoqi");ur.tpassword("666777");ur.tid(1);boolean b = dao.update(ur);system.out.println("testupdate:"+b);}public static void testdelete() throws sqlexception {boolean b = dao.delete(4);system.out.println("testdelete:"+b);}public static void testfindbyid() throws sqlexception {ur ur = dao.find(2);system.out.println(ur.getid() + "," + ur.getname() + ","+ ur.getpassword());}public static void testfindall() throws sqlexception {list<ur> list = dao.findall();for(ur ur : list) {system.out.println(ur.getid() + "," + ur.getname() + ","+ ur.getpa关于艺术的作文ssword());}}public static void main(string[] args) throws sqlexception {testinrt();testupdate();testdelete();testfindbyid();testfindall();}}

以上代码由多个测试函数组成，依次为：插入、修改、删除、根据id查询、查询所有

4、执行测试类

1.数据表ur原始数据如下：

执行后结果如下：

之中插入和删除都是针对第四个数据进行的操作，所以没有显现

java dbutils技术访问数据库

dbutils

dbutils是操作数据库的组件，对传统操作数据库的类进行二次封装，可以把结果集转化成list。

介绍

dbutils相对以往的连接数据库得到结果集的模式，代码更加简洁，访问更加迅速，这里我对一个我自级设计的cuisine表做一个简单的例子。

对数据库的查询语句的代码

对已有的菜系表cuisine查找对应菜系编号cuid的全部数据.

1、菜系表的实体类

// 菜系表的实体类public class cuisine {private static final long rialversionuid = 1l;private int cuid;private string cuname;public cuisine() {super();// todo auto-generated constructor stubthis.cuid = 0;this.cuname = "";}public cuisine(int cuid, string cuname) {super();this.cuid = cuid;this.cuname = cuname;}public int getcuid() {return cuid;}publ红色的书ic void tcuid(int cuid) {this.cuid = cuid;}public string getcuname() {return cuname;}public void tcuname(string cuname) {this.cuname = cuname;}@overridepublic string tostring() {return "cuisine [cuid=" + cuid + ", cuname=" + cuname + "]";}}

2、实现数据查询的方法

// 实现数据查询public cuisine getcuisine(cuisine cu) {//得到对应菜系的信息// todo auto-generated method stubqueryrunner queryrunner = new queryrunner();if(cu.getcuid() != 0){string sql = "lect * from cuisine where cuid = ?";try {return queryrunner.query(dbutilspro.getconnection(),sql,cu.getcuid(),new beanhandler(cuisine.class));} catch (sqlexception e) {// todo auto-generated catch blocke1.printstacktrace();}}return null;}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持www.887551.com。