JavaWeb完整案例详细步骤
废话少说，展示完整案例
主要实现功能
基本的CURD、分页查询、条件查询、批量删除
所使用的技术
- 前端：Vue+Ajax+Elememt-ui
- 后端：Web层（Servlet）+Service层+Dao层（持久层）+Mybatis
步骤：
第一步：创建项目、导入jar包、创建数据库、Element-ui、Axios框架
- pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.wfy</groupId>
<artifactId>BrandTest</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>BrandTest Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
<!-- servlet-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
</dependency>
<!-- mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.30</version>
</dependency>
<!-- ajax-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>2.0.14</version>
</dependency>
<!--mybatis-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.11</version>
<scope>compile</scope>
</dependency>
</dependencies>
<build>
<finalName>BrandTest</finalName>
</build>
</project>
- mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--起别名-->
<typeAliases>
<package name="com.wfy.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql:///test?useSSL=false&useServerPrepStmts=true"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--扫描mapper-->
<package name="com.wfy.mapper"/>
</mappers>
</configuration>
- 数据库sql文件
/*
Navicat Premium Data Transfer
Source Server : Mybatis
Source Server Type : MySQL
Source Server Version : 50528
Source Host : localhost:3306
Source Schema : test
Target Server Type : MySQL
Target Server Version : 50528
File Encoding : 65001
Date: 16/10/2022 09:32:18
*/
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for brand
-- ----------------------------
DROP TABLE IF EXISTS `brand`;
CREATE TABLE `brand` (
`id` int(11) NOT NULL AUTO_INCREMENT COMMENT '编号',
`brand_name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '品牌名',
`company_name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '公司名',
`ordered` int(11) NOT NULL COMMENT '排序字段',
`description` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '描述信息',
`status` int(11) NOT NULL COMMENT '状态',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 74 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact;
-- ----------------------------
-- Records of brand
-- ----------------------------
INSERT INTO `brand` VALUES (1, '小潮Team', '上海潮晟文化传播有限公司', 2, '带给别人快乐是一件很酷的事情', 1);
INSERT INTO `brand` VALUES (2, '宠物星球', '凌飞科技有限公司', 1, '为理想打造梦幻家园', 1);
INSERT INTO `brand` VALUES (3, '小潮Team', '上海潮晟文化传播有限公司', 3, '带给别人快乐是一件很酷的事情', 1);
INSERT INTO `brand` VALUES (4, '小潮Team', '上海潮晟文化传播有限公司', 5, '带给别人快乐是一件很酷的事情', 1);
INSERT INTO `brand` VALUES (5, '小潮Team', '上海潮晟文化传播有限公司', 10, '带给别人快乐是一件很酷的事情', 1);
INSERT INTO `brand` VALUES (6, '宠物星球', '凌飞科技有限公司', 15, '为理想打造梦幻家园', 1);
INSERT INTO `brand` VALUES (7, '宠物星球', '凌飞科技有限公司', 18, '为理想打造梦幻家园', 1);
INSERT INTO `brand` VALUES (8, '小米', '小米科技有限公司', 102, '为发烧而生', 0);
INSERT INTO `brand` VALUES (9, '华为', '华为科技有限公司', 20, '就是割韭菜', 0);
INSERT INTO `brand` VALUES (10, '三只松鼠', '三只松鼠股份有限公司', 50, '吃吃吃', 1);
INSERT INTO `brand` VALUES (11, '京东', '北京京东世纪贸易有限公司', 34, '嗖嗖嗖', 1);
INSERT INTO `brand` VALUES (12, '腾讯', '腾讯计算机系统有限公司', 45, '就是圈钱', 1);
INSERT INTO `brand` VALUES (13, '百度', '百度在线网络技术公司', 10, '搜的就是快', 1);
INSERT INTO `brand` VALUES (14, 'aa', 'aaa', 23, 'aaa', 0);
INSERT INTO `brand` VALUES (15, 'bbb', 'bbb', 24, 'bbb', 1);
INSERT INTO `brand` VALUES (16, 'ccc', 'ccc', 25, 'ccc', 0);
INSERT INTO `brand` VALUES (17, 'ddd', 'ddd', 26, 'ddd', 1);
INSERT INTO `brand` VALUES (18, 'eee', 'eee', 27, 'eee', 1);
INSERT INTO `brand` VALUES (19, 'fff', 'fff', 28, 'fff', 1);
INSERT INTO `brand` VALUES (20, 'ggg', 'ggg', 29, 'ggg', 1);
INSERT INTO `brand` VALUES (21, 'hhh', 'hhh', 30, 'hhh', 0);
INSERT INTO `brand` VALUES (22, 'iii', 'iii', 31, 'iii', 1);
INSERT INTO `brand` VALUES (23, 'jjj', 'jjj', 32, 'jjj', 0);
INSERT INTO `brand` VALUES (24, 'kkk', 'kkk', 33, 'kkk', 1);
INSERT INTO `brand` VALUES (25, 'lll', 'lll', 34, 'lll', 1);
INSERT INTO `brand` VALUES (26, 'mmm', 'mmm', 35, 'mmm', 1);
INSERT INTO `brand` VALUES (27, 'nnn', 'nnn', 36, 'nnn', 1);
INSERT INTO `brand` VALUES (28, '111', '111', 37, '111', 0);
INSERT INTO `brand` VALUES (29, '222', '222', 38, '222', 0);
INSERT INTO `brand` VALUES (30, '333', '333', 39, '333', 0);
INSERT INTO `brand` VALUES (31, '444', '444', 40, '444', 0);
INSERT INTO `brand` VALUES (32, '555', '555', 41, '555', 0);
INSERT INTO `brand` VALUES (33, '666', '666', 42, '666', 1);
INSERT INTO `brand` VALUES (34, '777', '777', 43, '777', 0);
INSERT INTO `brand` VALUES (35, '888', '888', 44, '888', 1);
SET FOREIGN_KEY_CHECKS = 1;
- Element-ui和Axios---需要自取
链接：https://pan.baidu.com/s/1vGP-cTM5H2r90xssVB1EYA?pwd=0323
提取码：0323
第二步：项目分析
首先，我们要先进行分析，要实现案例对品牌信息的操作，需要三层架构的相互调用和操作来实现。
- Web层（表现层）：表现层我们要实现通过对页面相应的操作，获取页面上的请求或者数据发送到Service层，然后通过Service层的一些方法将数据返回到Web层，进行显示
- Service层（业务逻辑层）：这里主要是进行方法的编写、数据的调度，将从前端拿到的数据或者请求传入到相应的方法体内，调用相应的方法实现相应的操作。
- Dao层（数据访问层）：主要创建pojo实体类，通过mapper映射的方式，获取数据库的数据。
第三步：废话少说开始编写
- 创建Maven项目，创建brand.html页面，导入axios.js和vue.js,以及element-ui的框架
这里用到的Element前端框架组件，可以参考：Element - 网站快速成型工具
<link rel='stylesheet' href='js/lib-master/theme-chalk/index.css'>
<script src='js/vue.js' charset='UTF-8'></script>
<script src='js/lib-master/index.js' charset='UTF-8'></script>
<script src='js/axios-0.18.0.js' charset='UTF-8'></script>
<!DOCTYPE html>
<html lang="en" >
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.el-table .warning-row {
background: oldlace;
}
.el-table .success-row {
background: #f0f9eb;
}
</style>
</head>
<body>
<div id="app">
<!-- 搜索表单 -->
<el-form :inline="true" :model="brand" class="demo-form-inline">
<el-form-item label="当前状态">
</el-form-item>
<el-select v-model="brand.status" placeholder="当前状态">
<el-option label="启用" value="1"></el-option>
<el-option label="禁用" value="0"></el-option>
</el-select>
<el-form-item label="企业名称">
<el-input v-model="brand.companyName" placeholder="企业名称"></el-input>
</el-form-item>
<el-form-item label="品牌名称">
<el-input v-model="brand.brandName" placeholder="品牌名称"></el-input>
</el-form-item>
<el-form-item>
<el-button type="primary" @click="onSubmit">查询</el-button>
</el-form-item>
</el-form>
<!-- 删除和新增按钮-->
<el-row>
<el-button type="danger" plain @click="deleteByIds">批量删除</el-button>
<el-button type="primary" @click="dialogVisible=true" plain>新增</el-button>
</el-row>
<!-- 新增数据的对话框表单-->
<el-dialog
title="编辑品牌"
:visible.sync="dialogVisible"
width="30%"
>
<el-form ref="form" :model="brand" label-width="80px">
<el-form-item label="品牌名称">
<el-input v-model="brand.brandName"></el-input>
</el-form-item>
<el-form-item label="企业名称">
<el-input v-model="brand.companyName"></el-input>
</el-form-item>
<el-form-item label="排序">
<el-input v-model="brand.ordered"></el-input>
</el-form-item>
<el-form-item label="备注">
<el-input type="textarea" v-model="brand.description"></el-input>
</el-form-item>
<el-form-item label="状态">
<el-switch v-model="brand.status" active-value="1" inactive-value="0"></el-switch>
</el-form-item>
<el-form-item>
<el-button type="primary" @click="addBrand">提交</el-button>
<el-button @click="dialogVisible = false">取消</el-button>
</el-form-item>
</el-form>
</el-dialog>
<!-- 更改数据的表单-->
<el-dialog
title="更改品牌数据信息"
:visible.sync="dialogVisible_update"
width="30%"
>
<template slot-scope="scope">
<el-form ref="form" :model="updateTable" label-width="80px">
<el-form-item label="品牌名称">
<el-input v-model="updateTable.brandName"></el-input>
</el-form-item>
<el-form-item label="企业名称">
<el-input v-model="updateTable.companyName"></el-input>
</el-form-item>
<el-form-item label="排序">
<el-input v-model="updateTable.ordered"></el-input>
</el-form-item>
<el-form-item label="备注">
<el-input type="textarea" v-model="updateTable.description"></el-input>
</el-form-item>
<el-form-item label="状态">
<el-switch v-model="updateTable.status" active-value="1" inactive-value="0"></el-switch>
</el-form-item>
<el-form-item>
<el-button type="primary" @click="updateBrand">提交</el-button>
<el-button @click="dialogVisible_update = false">取消</el-button>
</el-form-item>
</el-form>
</template>
</el-dialog>
<!-- 表格-->
<template >
<el-table
:data='tableData'
style='width: 100%'
:row-class-name='tableRowClassName'
@selection-change='handleSelectionChange'
>
<el-table-column
type='selection'
width='55'>
</el-table-column>
<el-table-column
type='index'
width='50'>
</el-table-column>
<el-table-column
prop='brandName'
label='品牌名称'
align='center'
>
</el-table-column>
<el-table-column
prop='companyName'
label='企业名称'
align='center'
>
</el-table-column>
<el-table-column
prop='ordered'
align='center'
label='排序'>
</el-table-column>
<el-table-column
prop='description'
align='center'
label='描述'>
</el-table-column>
<el-table-column
prop='statusStr'
align='center'
label='当前状态'>
</el-table-column>
<el-table-column
align='center'
label='操作'>
<template slot-scope="scope">
<el-row>
<el-button type='primary' @click="selectById(scope.row.id)" >修改</el-button>
<el-button type='danger'@click="deleteBrand(scope.row.id)">删除</el-button>
</el-row>
</template>
</el-table-column>
</el-table>
</template>
<!-- 分页工具条-->
<el-pagination
@size-change='handleSizeChange'
@current-change='handleCurrentChange'
:current-page='currentPage'
:page-sizes='[5, 10, 15, 20]'
:page-size='5'
layout='total, sizes, prev, pager, next, jumper'
:total='totalCount'>
</el-pagination>
</div>
<link rel='stylesheet' href='js/lib-master/theme-chalk/index.css'>
<script src='js/vue.js' charset='UTF-8'></script>
<script src='js/lib-master/index.js' charset='UTF-8'></script>
<script src='js/axios-0.18.0.js' charset='UTF-8'></script>
<script>
new Vue({
el:'#app',
mounted(){
this.selectByPage()
},
data() {
return {
//总记录数
totalCount:'',
//分页 --当前页码
currentPage:1 ,
//每页显示的条数
pageSize:5,
//新增表单的显示与隐藏的标记
dialogVisible: false,
dialogVisible_update:false,
//品牌模型数据
brand: {
status:'',
companyName: '',
brandName: '',
id:'',
ordered:'',
description:'',
},
updateTable:{
status:'',
companyName: '',
brandName1: '',
id:'',
ordered:'',
description:'',
},
//被选中的id数组
selectIds:[],
//复选框选择信息集合
multipleSelection: [],
//表格的数据
tableData: [{
brandName: '',
companyName: '',
ordered: '',
description:'',
status:''
}],
}
},
methods: {
//响应数据，显示所有信息
GetAll(){
console.log('提示语句')
//当页面加载完成后，发送异步请求，获取数据
axios({
method:'get',
url:'brand/selectAll',
}).then( resp=>{
this.tableData=resp.data ;
console.log('提示语句')
})
},
//查询分页的数据
selectByPage(){
axios({
method:'post',
url:'brand/selectByPageAndCondition?currentPage='+this.currentPage+'&pageSize='+this.pageSize,
data:this.brand,
}).then(response=>{
//设置表格数据
this.tableData= response.data.rows; //{rows:[],totalCount:}
//设置总记录数
this.totalCount=response.data.totalCount;
})
},
tableRowClassName({row, rowIndex}) {
if (rowIndex === 1) {
return 'warning-row';
} else if (rowIndex === 3) {
return 'success-row';
}
return '';
},
//复选框选中后执行的操作
handleSelectionChange(val) {
this.multipleSelection = val;
console.log(this.multipleSelection)
},
//查询的方法
onSubmit() {
//console.log(this.brand);
this.selectByPage();
},
//添加表单数据的方法
addBrand(){
//console.log(this.brand)
//发送ajax请求，添加数据
axios({
method:'post',
url: 'brand/add',
data: this.brand
}).then(resp=>{
if(resp.data=="success"){
//添加成功
this.selectByPage();
//关闭窗口
this.dialogVisible=false;
//添加成功的标识
this.$message({
showClose: true,
message: '成功添加数据',
type: 'success'
});
}
})
},
//删除一条指定数据操作
deleteBrand(id){
//弹窗提示是否删除
this.$confirm('此操作将永久删除该文件, 是否继续?', '提示', {
confirmButtonText: '确定',
cancelButtonText: '取消',
type: 'warning'
}).then(() => {
this.$message({
type: 'success',
message: '删除成功!'
});
}).catch(() => {
this.$message({
type: 'info',
message: '已取消删除'
});
});
axios({
method:'post',
url:'brand/deleteById',
data:id
}).then(response=>{
if(response.data=='success'){
//重新查询
this.selectByPage();
//显示成功提示
this.$message({
showClose: true,
message: '删除数据成功',
type: 'success'
});
}
})
},
//更改用户数据
//1.对用户数据进行回显操作
selectById(id){
axios({
method:'post',
url: 'brand/selectById',
data: id
}).then(response=>{
// console.log(id)
//回显数据
this.updateTable=response.data;
// console.log(_this.updateTable)
//弹出修改框
this.dialogVisible_update=true;
})
},
//2.对回显数据进行更改操作
updateBrand(){
axios({
method:'post',
url:'brand/updateBrand',
data:this.updateTable
}).then(resp=>{
if(resp.data=='success'){
//重新查询数据
this.selectByPage();
//关闭窗口
this.dialogVisible_update=false;
//更改成功提示
this.$message({
showClose: true,
message: '数据更改成功',
type: 'success'
});
}
})
},
//删除多条数据
deleteByIds(){
//弹出确认对话框
this.$confirm('此操作将永久删除该文件, 是否继续?', '提示', {
confirmButtonText: '确定',
cancelButtonText: '取消',
type: 'warning'
}).then(() => {
this.$message({
type: 'success',
message: '删除成功!'
});
}).catch(() => {
this.$message({
type: 'info',
message: '已取消删除'
});
});
//1.创建id数组[] 从this.multipleSelection里面获取id
for (let i = 0; i < this.multipleSelection.length; i++) {
let selectionElement=this.multipleSelection[i];
this.selectIds[i]=selectionElement.id;
//console.log(this.selectIds)
}
//2.发送ajax请求，并携带ids数据
axios({
method:'post',
url:'brand/deleteByIds',
data:this.selectIds
}).then(resp=>{
if(resp.data=='success'){
//删除成功
//重新查询数据
this.selectByPage();
//删除成功提示
this.$message({
showClose: true,
message: '删除成功',
type: 'success'
});
}
})
},
//分页工具条
handleSizeChange(val) {
//console.log(`每页 ${val} 条`);
//设置每页展示的条数
this.pageSize = val;
},
handleCurrentChange(val) {
// console.log(`当前页: ${val}`);
//重新设置当前页码数
this.currentPage=val;
this.selectByPage();
}
},
})
</script>
</body>
</html>
- Dao层
- 创建pojo实体类
package com.wfy.pojo;
public class Brand {
//id 主键
private Integer id;
//brandName 品牌名称
private String brandName;
//企业名称
private String companyName;
//排序字段
private Integer ordered;
//描述信息
private String description;
//状态： 0：禁用 1：启动
private Integer status;
private String statusStr;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getBrandName() {
return brandName;
}
public void setBrandName(String brandName) {
this.brandName = brandName;
}
public String getCompanyName() {
return companyName;
}
public void setCompanyName(String companyName) {
this.companyName = companyName;
}
public Integer getOrdered() {
return ordered;
}
public void setOrdered(Integer ordered) {
this.ordered = ordered;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Integer getStatus() {
return status;
}
//逻辑视图
public String getStatusStr(){
if(status==1){
return "启用";
}
return status==0 ?"禁用":"启用";
}
public void setStatus(Integer status) {
this.status = status;
}
@Override
public String toString() {
return "Brand{" +
"id=" + id +
", brandName='" + brandName + '\'' +
", companyName='" + companyName + '\'' +
", ordered=" + ordered +
", description='" + description + '\'' +
", status=" + status +
'}';
}
}
- PageBean实体类--分页查询
package com.wfy.pojo;
import java.util.List;
//分页查询的JavaBean
public class PageBean<T> {
//总记录数
private int totalCount;
//当前业数据
private List<T> rows;
public int getTotalCount() {
return totalCount;
}
public void setTotalCount(int totalCount) {
this.totalCount = totalCount;
}
public List<T> getRows() {
return rows;
}
public void setRows(List<T> rows) {
this.rows = rows;
}
}
- BrandMapper的接口和映射文件
package com.wfy.mapper;
import com.wfy.pojo.Brand;
import org.apache.ibatis.annotations.*;
import java.util.List;
public interface BrandMapper {
//查询所有
@Select("select * from brand")
@ResultMap("brandResultMap")
List<Brand> SelectAll();
//新增品牌
@Insert("insert into brand values (null,#{brandName},#{companyName},#{ordered},#{description},#{status})")
void AddBrand(Brand brand);
//根据id来获取指定品牌信息,实现数据的回显操作
@Select("select * from brand where id = #{id}")
@ResultMap("brandResultMap")
Brand SelectById(int id);
//更改品牌信息
@Update("update brand set brand_name=#{brandName},company_name=#{companyName},ordered=#{ordered},description=#{description} where id=#{id} ")
void UpdateBrand(Brand brand);
//删除指定品牌数据
@Delete("delete from brand where id =#{id}")
void deleteById(int id);
//删除多条数据
void DeleteByIds( @Param("ids") int[] ids);
//分页查询 begin--开始的索引 size--获取信息的条目数
@Select("select * from brand limit #{begin},#{size} ")
@ResultMap("brandResultMap")
List<Brand> SelectByPage(@Param("begin") int begin,@Param("size") int size);
//查询总信息条数
@Select("select count(*) from brand")
int SelectTotalCount();
//分页条件查询 begin--开始的索引 size--获取信息的条目数
List<Brand> SelectByPageAndCondition(@Param("begin") int begin,@Param("size") int size,@Param("brand")Brand brand);
//条件查询总信息条数
int SelectTotalCountByCondition(Brand brand);
}
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--
namespace:名称空间
数据库的字段名称 和 实体类的属性名称 不一样 则不能自动封装数据
* 方法： 1.起别名 ： 用as ,对不一样的列明起别名，让别名和列明相同
2.resultMap:完成不一样的属性名和列名的映射
1.定义<resultMap>标签
2.在<select>标签中，使用resultMap属性替换resultType属性
-->
<mapper namespace="com.wfy.mapper.BrandMapper">
<resultMap id="brandResultMap" type="brand">
<result property="brandName" column="brand_name"/>
<result property="companyName" column="company_name"/>
</resultMap>
<delete id="DeleteByIds">
delete from brand where id in
<foreach collection="ids" item="id" open="(" separator="," close=")">
#{id}
</foreach>
</delete>
<!-- where brand_name=#{brand.brandName}-->
<select id="SelectByPageAndCondition" resultMap="brandResultMap">
select *
from brand
<where>
<if test="brand.brandName !=null and brand.brandName!=''">
and brand_name like #{brand.brandName}
</if>
<if test="brand.companyName !=null and brand.companyName!=''">
and company_name like #{brand.companyName}
</if>
<if test="brand.status !=null">
and status=#{brand.status}
</if>
</where>
limit #{begin} ,#{size}
</select>
<select id="SelectTotalCountByCondition" resultType="java.lang.Integer">
select count(*)
from brand
<where>
<if test="brandName !=null and brandName!=''">
and brand_name like #{brandName}
</if>
<if test="companyName !=null and companyName!=''">
and company_name like #{companyName}
</if>
<if test="status !=null">
and status=#{status}
</if>
</where>
</select>
</mapper>
注意这里的映射文件需要在resource目录下创建分层目录，通过‘\’进行分割
及文件的目录名为：“ com\wfy\mapper”
- Service层(业务逻辑层)
因为我们需要不断的调用SqlSession的方法，通过mapper映像的方式，为了降低程序的耦合度，同时为了简化代码，通过接口的方式来实现对方法的调用
- 创建BrandService接口
package com.wfy.service;
import com.wfy.pojo.Brand;
import com.wfy.pojo.PageBean;
import java.util.List;
public interface BrandService {
//查询所有数据
public List<Brand> SelectAll();
//新增数据
void AddBrand(Brand brand);
//更改数据信息
//获取查询到的数据进行表格显现
Brand SelectById(int id);
void UpdateBrand(Brand brand);
//删除指定数据
void DeleteById(int id);
//删除多条数据
void DeleteByIds(int[] ids);
//分页查询 currentPage--当前页码 pageSize--每页展示条数
PageBean<Brand> SelectByPage(int currentPage,int pageSize);
//分页条件查询
PageBean<Brand> SelectByPageAndCondition(int currentPage,int pageSize,Brand brand);
}
- 创建BrandServiceImpl接口的实现方法
因为需要不断的调用SqlSessionFactoy工厂，为了简化代码，创建Util包，编写一个SqlSessionFactoryUtils来简化代码逻辑
package com.wfy.util;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.InputStream;
public class SqlSessionFactoryUtils {
private static SqlSessionFactory sqlSessionFactory;
static {
//静态代码块会随着类的加载而自动执行，且只执行一次
try {
String resource = "mybatis-config.xml";
InputStream inputStream = null;
inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public static SqlSessionFactory getSqlSessionFactory(){
return sqlSessionFactory;
}
}
package com.wfy.service.impl;
import com.wfy.mapper.BrandMapper;
import com.wfy.pojo.Brand;
import com.wfy.pojo.PageBean;
import com.wfy.service.BrandService;
import com.wfy.util.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import java.util.List;
public class BrandServiceImpl implements BrandService {
//1.创建sqlSessionFactory 工厂对象
SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
public List<Brand> SelectAll() {
//2.获取SqlSession对象
SqlSession sqlSession = factory.openSession();
//3.获取BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//4.调用方法
List<Brand> brands = mapper.SelectAll();
//5.释放资源
sqlSession.close();
return brands;
}
public void AddBrand(Brand brand) {
SqlSession sqlSession = factory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
mapper.AddBrand(brand);
sqlSession.commit();
sqlSession.close();
}
public Brand SelectById(int id) {
//2.获取SqlSession对象
SqlSession sqlSession = factory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
Brand brand = mapper.SelectById(id);
//关闭资源
sqlSession.close();
return brand;
}
public void UpdateBrand(Brand brand) {
SqlSession sqlSession = factory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
mapper.UpdateBrand(brand);
//提交事务、关闭资源
sqlSession.commit();
sqlSession.close();
}
public void DeleteById(int id) {
SqlSession sqlSession = factory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
mapper.deleteById(id);
sqlSession.commit();
sqlSession.close();
}
public void DeleteByIds(int[] ids) {
//2.获取SqlSession对象
SqlSession sqlSession = factory.openSession();
//3.获取BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//4.调用方法
mapper.DeleteByIds(ids);
sqlSession.commit();
sqlSession.close();
}
public PageBean<Brand> SelectByPage(int currentPage, int pageSize) {
//2.获取SqlSession对象
SqlSession sqlSession = factory.openSession();
//3.获取BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//4.计算开始索引=（当前页码数-1）*展示的信息条数
int begin=(currentPage-1) * pageSize;
//计算条目数
int size=pageSize;
//5.查询当前页数据
List<Brand> rows = mapper.SelectByPage(begin, size);
//6.查询总记录数
int totalCount = mapper.SelectTotalCount();
//7.封装PageBean对象
PageBean<Brand> pageBean=new PageBean<Brand>();
pageBean.setRows(rows);
pageBean.setTotalCount(totalCount);
//8.释放资源
sqlSession.close();
return pageBean;
}
public PageBean<Brand> SelectByPageAndCondition(int currentPage, int pageSize, Brand brand) {
//2.获取SqlSession对象
SqlSession sqlSession = factory.openSession();
//3.获取BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//4.计算开始索引=（当前页码数-1）*展示的信息条数
int begin=(currentPage-1) * pageSize;
//计算条目数
int size=pageSize;
//处理brand条件，设置模糊表达式
String brandName = brand.getBrandName();
if (brandName !=null&&brandName.length()>0){
brand.setBrandName("%"+brandName+"%");
}
String companyName = brand.getCompanyName();
if (companyName !=null&&companyName.length()>0){
brand.setCompanyName("%"+companyName+"%");
}
//5.查询当前页数据
List<Brand> rows = mapper.SelectByPageAndCondition(begin,size,brand);
//6.查询总记录数
int totalCount = mapper.SelectTotalCountByCondition(brand);
//7.封装PageBean对象
PageBean<Brand> pageBean=new PageBean<Brand>();
pageBean.setRows(rows);
pageBean.setTotalCount(totalCount);
//8.释放资源
sqlSession.close();
return pageBean;
}
}
- Servlet的编写
如果为了实现不同的方法，我们需要不断地调用HttpServlet,因此通过编写一个BaseServlet来代替HttpServlet
package com.wfy.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
//替换HttpServlet ,根据请求的最后一段路径来进行方法分发
public class BaseServlet extends HttpServlet {
//根据请求的最后一段路径来进行方法的分发
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.获取请求路径
String uri = req.getRequestURI(); //BrandTest/brand/SelectAllServlet
// System.out.println(uri);
//2.获取最后一段路径----方法名
int index=uri.lastIndexOf('/');
String methodName = uri.substring(index+1);
//System.out.println(methodName);
//3.执行方法
//3-1获取BrandServlet的字节码对象 class
// this:指代关系 谁调用我（this 所在的方法），我（this）代表谁
// System.out.println(this);//com.wfy.servlet.BrandServlet@61f761f5
Class<? extends BaseServlet> cls = this.getClass();
//3-2.获取方法的Method对象
try {
Method method = cls.getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
//3-3执行方法
method.invoke(this,req,resp);
} catch (NoSuchMethodException e) {
throw new RuntimeException(e);
} catch (InvocationTargetException e) {
throw new RuntimeException(e);
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
}
}
package com.wfy.servlet;
import com.alibaba.fastjson.JSON;
import com.wfy.pojo.Brand;
import com.wfy.pojo.PageBean;
import com.wfy.service.BrandService;
import com.wfy.service.impl.BrandServiceImpl;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.List;
@WebServlet("/brand/*")
public class BrandServlet extends BaseServlet{
private BrandService service = new BrandServiceImpl();
//获取全部信息
public void selectAll(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.调用service查询
List<Brand> brands = service.SelectAll();
//2.将数据转换为JSON
String toJSONString = JSON.toJSONString(brands);
//3.写数据
response.setContentType("text/json;charset=utf-8");
response.getWriter().write(toJSONString);
}
//新增信息
public void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
//1.接收品牌的数据
BufferedReader reader = request.getReader();
String params = reader.readLine();//json字符串
Brand brand = JSON.parseObject(params, Brand.class);
//2.调用service
service.AddBrand(brand);
//3.响应成功标识
response.getWriter().write("success");
}
//更改指定数据信息
//1-根据id查找指定数据，进行数据的回显操作
public void selectById(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.接收从web层传输过来的id
BufferedReader reader = request.getReader();
String params = reader.readLine();
Integer id = JSON.parseObject(params, int.class);
Brand brand = service.SelectById(new Integer(id).intValue());
//2.将数据转化为JSON
String toJSONString = JSON.toJSONString(brand);
//3.写入数据
response.setContentType("text/json;charset=utf-8");
response.getWriter().write(toJSONString);
}
//2-更改品牌的信息
public void updateBrand(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.接收web层传输过来的数据
BufferedReader reader = request.getReader();
String params = reader.readLine();
Brand brand = JSON.parseObject(params, Brand.class);
//将数据进行回显操作
// System.out.println(brand);
service.UpdateBrand(brand);
//3.响应成功标识
response.getWriter().write("success");
}
//删除指定数据
public void deleteById(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
//1.接收用户传递的id
BufferedReader reader = request.getReader();
String params = reader.readLine();
//将JSON数据转换为java数据
Integer id = JSON.parseObject(params, int.class);
service.DeleteById(new Integer(id).intValue());
//响应成功标识
response.getWriter().write("success");
}
//删除多条数据
public void deleteByIds(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
//1.接收需要删除品牌数据的ids
BufferedReader reader = request.getReader();
String params = reader.readLine();
// System.out.println(params);
//1-2将接收到的信息转换为int[]
int[] ids = JSON.parseObject(params, int[].class);
// for(int id:ids){
// System.out.println(id);
// }
//2.调用service
service.DeleteByIds(ids);
//3.响应成功标识
response.getWriter().write("success");
}
//分页查询
public void selectByPage(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.接收参数 当前页码 和 每页展示的条数 在url后进行拼接 url?currentPage=1&pageSize=5
String _currentPage = request.getParameter("currentPage");
String _pageSize = request.getParameter("pageSize");
int currentPage = Integer.parseInt(_currentPage);
int pageSize = Integer.parseInt(_pageSize);
//2.调用service进行查询
PageBean<Brand> pageBean = service.SelectByPage(currentPage, pageSize);
//3.转换成JSON对象
String jsonString = JSON.toJSONString(pageBean);
//4.将数据写入
response.setContentType("text/json;charset=utf-8");
response.getWriter().write(jsonString);
}
//分页条件查询
public void selectByPageAndCondition(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.接收参数 当前页码 和 每页展示的条数 在url后进行拼接 url?currentPage=1&pageSize=5
String _currentPage = request.getParameter("currentPage");
String _pageSize = request.getParameter("pageSize");
int currentPage = Integer.parseInt(_currentPage);
int pageSize = Integer.parseInt(_pageSize);
//获取条件查询的对象
BufferedReader reader = request.getReader();
String params = reader.readLine();
Brand brand = JSON.parseObject(params, Brand.class);
//2.调用service进行查询
PageBean<Brand> pageBean = service.SelectByPageAndCondition(currentPage,pageSize,brand);
//3.转换成JSON对象
String jsonString = JSON.toJSONString(pageBean);
//4.将数据写入
response.setContentType("text/json;charset=utf-8");
response.getWriter().write(jsonString);
}
}