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一、整合流程图

1.1 Spring整合Mybatis

1.2 Spring整合SpringMVC

二、表现层数据封装

2.1 问题引出

前端人员接收到很多不同数据格式，如下图：

不便于操作，因此，前端操作人员需要与后端人员统一数据格式

设计一个统一的数据返回结果类，如下：

2.2 统一返回结果数据格式 代码设计

Code.java自定义状态码类

package com.itheima.controller;//状态码
public class Code {public static final Integer SAVE_OK = 20011;public static final Integer DELETE_OK = 20021;public static final Integer UPDATE_OK = 20031;public static final Integer GET_OK = 20041;public static final Integer SAVE_ERR = 20010;public static final Integer DELETE_ERR = 20020;public static final Integer UPDATE_ERR = 20030;public static final Integer GET_ERR = 20040;
}

Result.java统一数据返回结果类

package com.itheima.controller;public class Result {//描述统一格式中的数据private Object data;//描述统一格式中的编码，用于区分操作，可以简化配置0或1表示成功失败private Integer code;//描述统一格式中的消息，可选属性private String msg;// 提供不同的构造方法public Result() {}public Result(Integer code,Object data) {this.data = data;this.code = code;}public Result(Integer code, Object data, String msg) {this.data = data;this.code = code;this.msg = msg;}public Object getData() {return data;}public void setData(Object data) {this.data = data;}public Integer getCode() {return code;}public void setCode(Integer code) {this.code = code;}public String getMsg() {return msg;}public void setMsg(String msg) {this.msg = msg;}
}

BookController.java修改controller类，统一返回数据格式

package com.itheima.controller;import com.itheima.domain.Book;
import com.itheima.service.BookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;import java.util.List;//统一每一个控制器方法返回值
@RestController
@RequestMapping("/books")
public class BookController {@Autowiredprivate BookService bookService;@PostMappingpublic Result save(@RequestBody Book book) {boolean flag = bookService.save(book);return new Result(flag ? Code.SAVE_OK:Code.SAVE_ERR,flag);}@PutMappingpublic Result update(@RequestBody Book book) {boolean flag = bookService.update(book);return new Result(flag ? Code.UPDATE_OK:Code.UPDATE_ERR,flag);}@DeleteMapping("/{id}")public Result delete(@PathVariable Integer id) {boolean flag = bookService.delete(id);return new Result(flag ? Code.DELETE_OK:Code.DELETE_ERR,flag);}@GetMapping("/{id}")public Result getById(@PathVariable Integer id) {Book book = bookService.getById(id);Integer code = book != null ? Code.GET_OK : Code.GET_ERR;String msg = book != null ? "" : "数据查询失败，请重试！";return new Result(code,book,msg);}@GetMappingpublic Result getAll() {List<Book> bookList = bookService.getAll();Integer code = bookList != null ? Code.GET_OK : Code.GET_ERR;String msg = bookList != null ? "" : "数据查询失败，请重试！";return new Result(code,bookList,msg);}
}

三、异常处理器

3.1 概述

3.2 异常处理方案

定义异常编码Code.class

package com.itheima.controller;//状态码
public class Code {public static final Integer SAVE_OK = 20011;public static final Integer DELETE_OK = 20021;public static final Integer UPDATE_OK = 20031;public static final Integer GET_OK = 20041;public static final Integer SAVE_ERR = 20010;public static final Integer DELETE_ERR = 20020;public static final Integer UPDATE_ERR = 20030;public static final Integer GET_ERR = 20040;public static final Integer SYSTEM_ERR = 50001;public static final Integer SYSTEM_TIMEOUT_ERR = 50002;public static final Integer SYSTEM_UNKNOW_ERR = 59999;public static final Integer BUSINESS_ERR = 60002;
}

定义业务异常BusinessException.class

package com.itheima.exception;
//自定义异常处理器，用于封装异常信息，对异常进行分类
public class BusinessException extends RuntimeException{private Integer code;public Integer getCode() {return code;}public void setCode(Integer code) {this.code = code;}public BusinessException(Integer code, String message) {super(message);this.code = code;}public BusinessException(Integer code, String message, Throwable cause) {super(message, cause);this.code = code;}}

定义系统异常SystemExceptionException.class

package com.itheima.exception;//自定义异常处理器，用于封装异常信息，对异常进行分类
public class SystemException extends RuntimeException{private Integer code;public Integer getCode() {return code;}public void setCode(Integer code) {this.code = code;}// 构造方法public SystemException(Integer code, String message) {super(message);this.code = code;}public SystemException(Integer code, String message, Throwable cause) {super(message, cause);this.code = code;}}

拦截异常并处理SystemExceptionException.class

package com.itheima.controller;import com.itheima.exception.BusinessException;
import com.itheima.exception.SystemException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;//@RestControllerAdvice用于标识当前类为REST风格对应的异常处理器
@RestControllerAdvice
public class ProjectExceptionAdvice {//@ExceptionHandler用于设置当前处理器类对应的异常类型@ExceptionHandler(SystemException.class)public Result doSystemException(SystemException ex){//记录日志//发送消息给运维//发送邮件给开发人员,ex对象发送给开发人员return new Result(ex.getCode(),null,ex.getMessage());}@ExceptionHandler(BusinessException.class)public Result doBusinessException(BusinessException ex){return new Result(ex.getCode(),null,ex.getMessage());}//除了自定义的异常处理器，保留对Exception类型的异常处理，用于处理非预期的异常@ExceptionHandler(Exception.class)public Result doOtherException(Exception ex){//记录日志//发送消息给运维//发送邮件给开发人员,ex对象发送给开发人员return new Result(Code.SYSTEM_UNKNOW_ERR,null,"系统繁忙，请稍后再试！");}
}

书写异常

package com.itheima.controller;import com.itheima.domain.Book;
import com.itheima.exception.BusinessException;
import com.itheima.exception.SystemException;
import com.itheima.service.BookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;import java.util.List;//统一每一个控制器方法返回值
@RestController
@RequestMapping("/books")
public class BookController {@Autowiredprivate BookService bookService;@GetMapping("/{id}")public Result getById(@PathVariable Integer id) {if(id == 1){throw new BusinessException(Code.BUSINESS_ERR,"写错了噢");}try {int i = 1 / 0;}catch(Exception e){throw new SystemException(Code.SYSTEM_TIMEOUT_ERR,"访问超时");}Book book = bookService.getById(id);Integer code = book != null ? Code.GET_OK : Code.GET_ERR;String msg = book != null ? "" : "数据查询失败，请重试！";return new Result(code,book,msg);}}

四、前端

编写处理前端路径的配置器SpringMvcSupport.class

package com.itheima.config;import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;@Configuration
public class SpringMvcSupport extends WebMvcConfigurationSupport {@Overrideprotected void addResourceHandlers(ResourceHandlerRegistry registry) {registry.addResourceHandler("/pages/**").addResourceLocations("/pages/");registry.addResourceHandler("/css/**").addResourceLocations("/css/");registry.addResourceHandler("/js/**").addResourceLocations("/js/");registry.addResourceHandler("/plugins/**").addResourceLocations("/plugins/");}
}

前端代码books.html

<!DOCTYPE html><html><head><!-- 页面meta --><meta charset="utf-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><title>SpringMVC案例</title><meta content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=no" name="viewport"><!-- 引入样式 --><link rel="stylesheet" href="../plugins/elementui/index.css"><link rel="stylesheet" href="../plugins/font-awesome/css/font-awesome.min.css"><link rel="stylesheet" href="../css/style.css"></head><body class="hold-transition"><div id="app"><div class="content-header"><h1>图书管理</h1></div><div class="app-container"><div class="box"><div class="filter-container"><el-input placeholder="图书名称" v-model="pagination.queryString" style="width: 200px;" class="filter-item"></el-input><el-button @click="getAll()" class="dalfBut">查询</el-button><el-button type="primary" class="butT" @click="handleCreate()">新建</el-button></div><el-table size="small" current-row-key="id" :data="dataList" stripe highlight-current-row><el-table-column type="index" align="center" label="序号"></el-table-column><el-table-column prop="type" label="图书类别" align="center"></el-table-column><el-table-column prop="name" label="图书名称" align="center"></el-table-column><el-table-column prop="description" label="描述" align="center"></el-table-column><el-table-column label="操作" align="center"><template slot-scope="scope"><el-button type="primary" size="mini" @click="handleUpdate(scope.row)">编辑</el-button><el-button type="danger" size="mini" @click="handleDelete(scope.row)">删除</el-button></template></el-table-column></el-table><!-- 新增标签弹层 --><div class="add-form"><el-dialog title="新增图书" :visible.sync="dialogFormVisible"><el-form ref="dataAddForm" :model="formData" :rules="rules" label-position="right" label-width="100px"><el-row><el-col :span="12"><el-form-item label="图书类别" prop="type"><el-input v-model="formData.type"/></el-form-item></el-col><el-col :span="12"><el-form-item label="图书名称" prop="name"><el-input v-model="formData.name"/></el-form-item></el-col></el-row><el-row><el-col :span="24"><el-form-item label="描述"><el-input v-model="formData.description" type="textarea"></el-input></el-form-item></el-col></el-row></el-form><div slot="footer" class="dialog-footer"><el-button @click="dialogFormVisible = false">取消</el-button><el-button type="primary" @click="handleAdd()">确定</el-button></div></el-dialog></div><!-- 编辑标签弹层 --><div class="add-form"><el-dialog title="编辑检查项" :visible.sync="dialogFormVisible4Edit"><el-form ref="dataEditForm" :model="formData" :rules="rules" label-position="right" label-width="100px"><el-row><el-col :span="12"><el-form-item label="图书类别" prop="type"><el-input v-model="formData.type"/></el-form-item></el-col><el-col :span="12"><el-form-item label="图书名称" prop="name"><el-input v-model="formData.name"/></el-form-item></el-col></el-row><el-row><el-col :span="24"><el-form-item label="描述"><el-input v-model="formData.description" type="textarea"></el-input></el-form-item></el-col></el-row></el-form><div slot="footer" class="dialog-footer"><el-button @click="dialogFormVisible4Edit = false">取消</el-button><el-button type="primary" @click="handleEdit()">确定</el-button></div></el-dialog></div></div></div></div></body><!-- 引入组件库 --><script src="../js/vue.js"></script><script src="../plugins/elementui/index.js"></script><script type="text/javascript" src="../js/jquery.min.js"></script><script src="../js/axios-0.18.0.js"></script><script>var vue = new Vue({el: '#app',data:{pagination: {},dataList: [],//当前页要展示的列表数据formData: {},//表单数据dialogFormVisible: false,//控制表单是否可见dialogFormVisible4Edit:false,//编辑表单是否可见rules: {//校验规则type: [{ required: true, message: '图书类别为必填项', trigger: 'blur' }],name: [{ required: true, message: '图书名称为必填项', trigger: 'blur' }]}},//钩子函数，VUE对象初始化完成后自动执行created() {this.getAll();},methods: {//列表getAll() {//发送ajax请求axios.get("/books").then((res)=>{this.dataList = res.data.data;});},//弹出添加窗口handleCreate() {this.dialogFormVisible = true;this.resetForm();},//重置表单resetForm() {this.formData = {};},//添加handleAdd () {//发送ajax请求axios.post("/books",this.formData).then((res)=>{console.log(res.data);//如果操作成功，关闭弹层，显示数据if(res.data.code == 20011){this.dialogFormVisible = false;this.$message.success("添加成功");}else if(res.data.code == 20010){this.$message.error("添加失败");}else{this.$message.error(res.data.msg);}}).finally(()=>{this.getAll();});},//弹出编辑窗口handleUpdate(row) {// console.log(row);   //row.id 查询条件//查询数据，根据id查询axios.get("/books/"+row.id).then((res)=>{// console.log(res.data.data);if(res.data.code == 20041){//展示弹层，加载数据this.formData = res.data.data;this.dialogFormVisible4Edit = true;}else{this.$message.error(res.data.msg);}});},//编辑handleEdit() {//发送ajax请求axios.put("/books",this.formData).then((res)=>{//将信息打印在控制台上console.log(res.data)//如果操作成功，关闭弹层，显示数据if(res.data.code == 20031){this.dialogFormVisible4Edit = false;this.$message.success("修改成功");}else if(res.data.code == 20030){this.$message.error("修改失败");}else{this.$message.error(res.data.msg);}}).finally(()=>{this.getAll();});},// 删除handleDelete(row) {//1.弹出提示框this.$confirm("此操作永久删除当前数据，是否继续？","提示",{type:'info'}).then(()=>{//2.做删除业务axios.delete("/books/"+row.id).then((res)=>{if(res.data.code == 20021){this.$message.success("删除成功");}else{this.$message.error("删除失败");}}).finally(()=>{this.getAll();});}).catch(()=>{//3.取消删除this.$message.info("取消删除操作");});}}})</script></html>

五、拦截器

5.1 概念

拦截器的执行流程

5.2 入门案例

第一步：声明拦截器的bean，并实现HandlerInterceptor接口，拦截器Intercepter一般放在controller（业务层）包下，需要在类前添加@Component注解。
当preHandle返回值类型可以拦截控制的执行，true放行，false终止。

@Component
//定义拦截器类，实现HandlerInterceptor接口
//注意当前类必须受Spring容器控制
public class ProjectInterceptor implements HandlerInterceptor {@Override//原始方法调用前执行的内容//返回值类型可以拦截控制的执行，true放行，false终止public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {String contentType = request.getHeader("Content-Type");HandlerMethod hm = (HandlerMethod)handler;System.out.println("preHandle..."+contentType);return true;}@Override//原始方法调用后执行的内容public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {System.out.println("postHandle...");}@Override//原始方法调用完成后执行的内容public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {System.out.println("afterCompletion...");}
}

第二步：定义配置类，继承WebMvcConfigurationSupport，实现方法addInterceptors，需要在类前添加@Configuration注解

@Configuration
public class SpringMvcSupport extends WebMvcConfigurationSupport {@Autowiredprivate ProjectInterceptor projectInterceptor;@Overrideprotected void addResourceHandlers(ResourceHandlerRegistry registry) {registry.addResourceHandler("/pages/**").addResourceLocations("/pages/");}@Overrideprotected void addInterceptors(InterceptorRegistry registry) {//配置拦截器registry.addInterceptor(projectInterceptor).addPathPatterns("/books","/books/*");}
}

第三步：在SpringMvc的配置类前添加@ComponentScan({“com.itheima.controller”,“com.itheima.config”})，以便拦截器ProjectInterceptor和配置类SpringMvcSupport被SpringMvc扫描到。

@Configuration
@ComponentScan({"com.itheima.controller"})
@EnableWebMvc
public class SpringMvcConfig{
}

最后，第二、三步可以合在一起简化开发

@Configuration
@ComponentScan({"com.itheima.controller","com.itheima.config"})
@EnableWebMvc
//实现WebMvcConfigurer接口可以简化开发，但具有一定的侵入性
public class SpringMvcConfig implements WebMvcConfigurer {@Autowiredprivate ProjectInterceptor projectInterceptor;@Autowiredprivate ProjectInterceptor2 projectInterceptor2;@Overridepublic void addInterceptors(InterceptorRegistry registry) {//配置多拦截器registry.addInterceptor(projectInterceptor).addPathPatterns("/books","/books/*");registry.addInterceptor(projectInterceptor2).addPathPatterns("/books","/books/*");}
}

5.3 拦截器参数

5.4 拦截器链