933 lines
27 KiB
Markdown
933 lines
27 KiB
Markdown
# springmvc基础（基于xml配置）
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**开发环境：IDEA**
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**spring版本：5.1.3.RELEASE**
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**本部分内容官方文档链接：[Web Servlet](https://docs.spring.io/spring/docs/5.1.3.RELEASE/spring-framework-reference/web.html#spring-web)**
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## 一、搭建hello spring工程
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### 1.1 项目搭建
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1.新建maven web工程，并引入相应的依赖
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```xml
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<properties>
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<spring-base-version>5.1.3.RELEASE</spring-base-version>
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</properties>
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<dependencies>
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<dependency>
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<groupId>org.springframework</groupId>
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<artifactId>spring-context</artifactId>
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<version>${spring-base-version}</version>
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</dependency>
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<dependency>
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<groupId>org.springframework</groupId>
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<artifactId>spring-beans</artifactId>
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<version>${spring-base-version}</version>
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</dependency>
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<dependency>
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<groupId>org.springframework</groupId>
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<artifactId>spring-core</artifactId>
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<version>${spring-base-version}</version>
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</dependency>
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<dependency>
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<groupId>org.springframework</groupId>
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<artifactId>spring-web</artifactId>
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<version>${spring-base-version}</version>
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</dependency>
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<dependency>
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<groupId>org.springframework</groupId>
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<artifactId>spring-webmvc</artifactId>
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<version>${spring-base-version}</version>
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</dependency>
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<dependency>
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<groupId>javax.servlet</groupId>
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<artifactId>javax.servlet-api</artifactId>
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<version>4.0.1</version>
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<scope>provided</scope>
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</dependency>
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</dependencies>
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```
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2.配置web.xml
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```xml
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<?xml version="1.0" encoding="UTF-8"?>
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<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
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http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
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version="3.1">
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<!--配置spring前端控制器-->
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<servlet>
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<servlet-name>springMvc</servlet-name>
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<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
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<init-param>
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<param-name>contextConfigLocation</param-name>
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<param-value>classpath:springApplication.xml</param-value>
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</init-param>
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<load-on-startup>1</load-on-startup>
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</servlet>
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<servlet-mapping>
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<servlet-name>springMvc</servlet-name>
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<url-pattern>/</url-pattern>
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</servlet-mapping>
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</web-app>
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```
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3.在resources下新建springApplication.xml文件，文件内容如下:
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```xml
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<?xml version="1.0" encoding="UTF-8"?>
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<beans xmlns="http://www.springframework.org/schema/beans"
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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xmlns:context="http://www.springframework.org/schema/context"
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xmlns:mvc="http://www.springframework.org/schema/mvc"
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xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
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http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
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http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
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<!-- 开启注解包扫描-->
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<context:component-scan base-package="com.heibaiying.*"/>
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<!--使用默认的Servlet来响应静态文件 详见 1.2 -->
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<mvc:default-servlet-handler/>
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<!-- 开启注解驱动 详见 1.2 -->
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<mvc:annotation-driven/>
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<!-- 配置视图解析器 -->
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<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
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id="internalResourceViewResolver">
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<!-- 前缀 -->
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<property name="prefix" value="/WEB-INF/jsp/"/>
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<!-- 后缀 -->
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<property name="suffix" value=".jsp"/>
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</bean>
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</beans>
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```
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4.在src 下新建controller用于测试
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```java
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package com.heibaiying.controller;
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import com.heibaiying.exception.NoAuthException;
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import org.springframework.stereotype.Controller;
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import org.springframework.web.bind.annotation.RequestMapping;
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/**
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* @author : heibaiying
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* @description : hello spring
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*/
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@Controller
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@RequestMapping("mvc")
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public class HelloController {
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@RequestMapping("hello")
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private String hello() {
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return "hello";
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}
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}
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```
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5.在WEB-INF 下新建jsp文件夹，新建hello.jsp 文件
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```jsp
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<%@ page contentType="text/html;charset=UTF-8" language="java" %>
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<html>
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<head>
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<title>Title</title>
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</head>
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<body>
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Hello Spring MVC!
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</body>
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</html>
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```
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6.启动tomcat服务，访问localhost:8080/mvc/hello
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### 1.2 相关配置讲解
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**1.\<mvc:default-servlet-handler/>**
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在web.xml配置中，我们将DispatcherServlet的拦截路径设置为“\”，则spring会捕获所有web请求，包括对静态资源的请求，为了正确处理对静态资源的请求，spring提供了两种解决方案：
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- 配置\<mvc:default-servlet-handler/> ： 配置<mvc:default-servlet-handler />后，会在Spring MVC上下文中定义一个org.springframework.web.servlet.resource.DefaultServletHttpRequestHandler，它会对进入DispatcherServlet的URL进行筛查，如果发现是静态资源的请求，就将该请求转由Web应用服务器默认的Servlet处理，如果不是静态资源的请求，才由DispatcherServlet继续处理。
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- 配置\<mvc:resources /> ：指定静态资源的位置和路径映射：
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```xml
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<mvc:resources location="/img/" mapping="/img/**"/>
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<mvc:resources location="/js/" mapping="/js/**"/>
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<mvc:resources location="/css/" mapping="/css/**"/>
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```
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**2.\<mvc:annotation-driven/>**
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<mvc:annotation-driven /> 会自动注册DefaultAnnotationHandlerMapping与AnnotationMethodHandlerAdapter
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两个bean,用以支持@Controllers分发请求。并提供了数据绑定、参数转换、json转换等功能，所以必须加上这个配置。
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## 二、配置自定义拦截器
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1.创建自定义拦截器，实现接口HandlerInterceptor（这里我们创建两个拦截器，用于测试拦截器方法的执行顺序）
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```java
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package com.heibaiying.interceptors;
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import org.springframework.web.servlet.HandlerInterceptor;
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import org.springframework.web.servlet.ModelAndView;
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import javax.servlet.http.HttpServletRequest;
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import javax.servlet.http.HttpServletResponse;
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/**
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* @author : heibaiying
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* @description : spring5 中 preHandle，postHandle，afterCompletion 在接口中被声明为默认方法
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*/
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public class MyFirstInterceptor implements HandlerInterceptor {
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public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
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System.out.println("进入第一个拦截器preHandle");
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return true;
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}
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// 需要注意的是，如果对应的程序报错，不一定会进入这个方法 但一定会进入afterCompletion这个方法
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public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
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System.out.println("进入第一个拦截器postHandle");
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}
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public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
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System.out.println("进入第一个拦截器afterCompletion");
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}
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}
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```
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```java
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package com.heibaiying.interceptors;
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import org.springframework.web.servlet.HandlerInterceptor;
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import org.springframework.web.servlet.ModelAndView;
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import javax.servlet.http.HttpServletRequest;
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import javax.servlet.http.HttpServletResponse;
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/**
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* @author : heibaiying
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* @description : spring5 中 preHandle，postHandle，afterCompletion 在接口中被声明为默认方法
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*/
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public class MySecondInterceptor implements HandlerInterceptor {
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public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
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System.out.println("进入第二个拦截器preHandle");
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return true;
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}
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public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
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System.out.println("进入第二个拦截器postHandle");
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}
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public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
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System.out.println("进入第二个拦截器afterCompletion");
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}
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}
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```
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2.在springApplication.xml中注册自定义拦截器
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```xml
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<!--配置拦截器-->
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<mvc:interceptors>
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<mvc:interceptor>
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<mvc:mapping path="/mvc/**"/>
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<mvc:exclude-mapping path="/mvc/login"/>
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<bean class="com.heibaiying.interceptors.MyFirstInterceptor"/>
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</mvc:interceptor>
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<mvc:interceptor>
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<mvc:mapping path="/mvc/**"/>
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<bean class="com.heibaiying.interceptors.MySecondInterceptor"/>
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</mvc:interceptor>
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</mvc:interceptors>
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```
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3.关于多个拦截器方法执行顺序的说明
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拦截器的执行顺序是按声明的先后顺序执行的，先声明的拦截器中的preHandle方法会先执行，然而它的postHandle方法和afterCompletion方法却会后执行。
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## 三、全局异常处理
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1.定义自定义异常
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```java
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package com.heibaiying.exception;
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/**
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* @author : heibaiying
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* @description : 自定义无权限异常
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*/
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public class NoAuthException extends RuntimeException {
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public NoAuthException() {
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super();
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}
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public NoAuthException(String message) {
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super(message);
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}
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public NoAuthException(String message, Throwable cause) {
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super(message, cause);
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}
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public NoAuthException(Throwable cause) {
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super(cause);
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}
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}
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```
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2.实现自定义异常处理器
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```java
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package com.heibaiying.exception;
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import org.springframework.web.servlet.HandlerExceptionResolver;
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import org.springframework.web.servlet.ModelAndView;
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import javax.servlet.http.HttpServletRequest;
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import javax.servlet.http.HttpServletResponse;
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/**
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* @author : heibaiying
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* @description : 无权限异常处理机制
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*/
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public class NoAuthExceptionResolver implements HandlerExceptionResolver {
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public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
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if (ex instanceof NoAuthException && !isAjax(request)) {
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return new ModelAndView("NoAuthPage");
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}
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return new ModelAndView();
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}
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// 判断是否是Ajax请求
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private boolean isAjax(HttpServletRequest request) {
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return "XMLHttpRequest".equalsIgnoreCase(request.getHeader("X-Requested-With"));
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}
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}
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```
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3.在springApplication.xml注册自定义异常处理器
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```xml
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<!--配置全局异常处理器-->
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<bean class="com.heibaiying.exception.NoAuthExceptionResolver"/>
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```
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4.定义测试controller，抛出自定义异常
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```java
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@Controller
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@RequestMapping("mvc")
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public class HelloController {
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@RequestMapping("hello")
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private String hello() {
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return "hello";
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}
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@RequestMapping("auth")
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private void auth() {
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throw new NoAuthException("没有对应的访问权限！");
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}
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}
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```
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注：调用这个controller时，同时也可以验证在拦截器部分提到的：如果对应的程序报错，拦截器不一定会进入postHandle这个方法 但一定会进入afterCompletion这个方法
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## 四、参数绑定
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### 4.1 参数绑定
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1.新建Programmer.java
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```java
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package com.heibaiying.bean;
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import lombok.Data;
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/**
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* @author : heibaiying
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* @description :
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*/
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@Data
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public class Programmer {
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private String name;
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private int age;
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private float salary;
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private String birthday;
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}
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```
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注：@Data 是lombok包下的注解，用来生成相应的set、get方法，使得类的书写更为简洁。
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2.新建ParamBindController.java 文件
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```java
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package com.heibaiying.controller;
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import com.heibaiying.bean.Programmer;
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import org.springframework.format.annotation.DateTimeFormat;
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import org.springframework.format.datetime.DateFormatter;
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import org.springframework.stereotype.Controller;
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import org.springframework.ui.Model;
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import org.springframework.web.bind.WebDataBinder;
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import org.springframework.web.bind.annotation.InitBinder;
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import org.springframework.web.bind.annotation.PostMapping;
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import org.springframework.web.bind.annotation.RequestMapping;
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import java.util.Date;
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/**
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* @author : heibaiying
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* @description :参数绑定
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*/
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@Controller
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public class ParamBindController {
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@InitBinder
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protected void initBinder(WebDataBinder binder) {
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binder.addCustomFormatter(new DateFormatter("yyyy-MM-dd HH:mm:ss"));
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}
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// 参数绑定与日期格式转换
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@RequestMapping("param")
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public String param(String name, int age, double salary, @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss") Date birthday, Model model) {
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model.addAttribute("name", name);
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model.addAttribute("age", age);
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model.addAttribute("salary", salary);
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model.addAttribute("birthday", birthday);
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return "param";
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}
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@RequestMapping("param2")
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public String param2(String name, int age, double salary, Date birthday, Model model) {
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model.addAttribute("name", name);
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model.addAttribute("age", age);
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model.addAttribute("salary", salary);
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model.addAttribute("birthday", birthday);
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return "param";
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}
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@PostMapping("param3")
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public String param3(Programmer programmer, String extendParam, Model model) {
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System.out.println("extendParam" + extendParam);
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model.addAttribute("p", programmer);
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return "param";
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}
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}
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```
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3.新建param.jsp 文件
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```jsp
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<%@ page contentType="text/html;charset=UTF-8" language="java" %>
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<html>
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<head>
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<title>Restful</title>
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</head>
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<body>
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<ul>
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<li>姓名：${empty name ? p.name : name}</li>
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<li>年龄：${empty age ? p.age : age}</li>
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<li>薪酬：${empty salary ? p.salary : salary}</li>
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<li>生日：${empty birthday ? p.birthday : birthday}</li>
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</ul>
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</body>
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</html>
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```
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4.启动tomcat，用[postman](https://www.getpostman.com/)软件发送请求进行测试
|
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### 4.2 关于日期格式转换的三种方法
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1.如上实例代码所示，在对应的controller中初始化绑定
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|
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```java
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@InitBinder
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protected void initBinder(WebDataBinder binder) {
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binder.addCustomFormatter(new DateFormatter("yyyy-MM-dd HH:mm:ss"));
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}
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```
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2.利用@DateTimeFormat注解，如果是用实体类去接收参数，则在对应的属性上声明
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```java
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public String param(@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss") Date birthday)
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```
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3.使用全局的日期格式绑定，新建自定义日期格式转化类，之后在springApplication.xml中进行注册
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|
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```java
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package com.heibaiying.convert;
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|
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import org.springframework.core.convert.converter.Converter;
|
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|
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import java.text.SimpleDateFormat;
|
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import java.util.Date;
|
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|
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/**
|
||
* @author : heibaiying
|
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* @description :
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*/
|
||
public class CustomDateConverter implements Converter<String, Date> {
|
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|
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public Date convert(String s) {
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try {
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SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
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return simpleDateFormat.parse(s);
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} catch (Exception e) {
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e.printStackTrace();
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}
|
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return null;
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}
|
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}
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```
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|
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springApplication.xml
|
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|
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```xml
|
||
<!-- 全局日期格式转换 -->
|
||
<bean id="formattingConversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
|
||
<property name="converters">
|
||
<list>
|
||
<bean class="com.heibaiying.convert.CustomDateConverter"/>
|
||
</list>
|
||
</property>
|
||
</bean>
|
||
```
|
||
|
||
|
||
|
||
## 五、数据校验
|
||
|
||
1.spring支持的数据校验是JSR303的标准，需要引入依赖的jar包
|
||
|
||
```java
|
||
<!-- 数据校验依赖包 -->
|
||
<dependency>
|
||
<groupId>org.hibernate.validator</groupId>
|
||
<artifactId>hibernate-validator</artifactId>
|
||
<version>6.0.13.Final</version>
|
||
</dependency>
|
||
<dependency>
|
||
<groupId>javax.validation</groupId>
|
||
<artifactId>validation-api</artifactId>
|
||
<version>2.0.1.Final</version>
|
||
</dependency>
|
||
```
|
||
|
||
2.新建测试ParamValidController.java，主要是在需要校验的参数前加上@Validated，声明参数需要被校验，同时加上bindingResult参数，这个参数中包含了校验的结果
|
||
|
||
```java
|
||
package com.heibaiying.controller;
|
||
|
||
import com.heibaiying.bean.Programmer;
|
||
import org.hibernate.validator.constraints.Length;
|
||
import org.springframework.format.annotation.DateTimeFormat;
|
||
import org.springframework.format.datetime.DateFormatter;
|
||
import org.springframework.stereotype.Controller;
|
||
import org.springframework.ui.Model;
|
||
import org.springframework.validation.BindingResult;
|
||
import org.springframework.validation.ObjectError;
|
||
import org.springframework.validation.annotation.Validated;
|
||
import org.springframework.web.bind.WebDataBinder;
|
||
import org.springframework.web.bind.annotation.InitBinder;
|
||
import org.springframework.web.bind.annotation.PostMapping;
|
||
import org.springframework.web.bind.annotation.RequestMapping;
|
||
import org.springframework.web.bind.annotation.RestController;
|
||
|
||
import javax.validation.constraints.Min;
|
||
import javax.validation.constraints.NotNull;
|
||
import java.util.Date;
|
||
import java.util.List;
|
||
|
||
/**
|
||
* @author : heibaiying
|
||
* @description :数据校验
|
||
*/
|
||
@RestController
|
||
public class ParamValidController {
|
||
|
||
|
||
@PostMapping("validate")
|
||
public void valid(@Validated Programmer programmer,
|
||
BindingResult bindingResult) {
|
||
List<ObjectError> allErrors = bindingResult.getAllErrors();
|
||
for (ObjectError error : allErrors) {
|
||
System.out.println(error.getDefaultMessage());
|
||
}
|
||
}
|
||
|
||
}
|
||
|
||
```
|
||
|
||
3.在Programmer.java的对应属性上加上注解约束(支持的注解可以在javax.validation.constraints包中查看)
|
||
|
||
```java
|
||
package com.heibaiying.bean;
|
||
|
||
import lombok.Data;
|
||
|
||
import javax.validation.constraints.Min;
|
||
import javax.validation.constraints.NotNull;
|
||
|
||
/**
|
||
* @author : heibaiying
|
||
* @description :
|
||
*/
|
||
@Data
|
||
public class Programmer {
|
||
|
||
@NotNull
|
||
private String name;
|
||
|
||
@Min(value = 0,message = "年龄不能为负数！" )
|
||
private int age;
|
||
|
||
@Min(value = 0,message = "薪酬不能为负数！" )
|
||
private float salary;
|
||
|
||
private String birthday;
|
||
}
|
||
|
||
```
|
||
|
||
## 六、文件上传与下载
|
||
|
||
#### 6.1 文件上传
|
||
|
||
1.在springApplication.xml中进行配置，使之支持文件上传
|
||
|
||
```xml
|
||
<!--配置文件上传-->
|
||
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
|
||
<!--文件最大限制-->
|
||
<property name="maxUploadSize" value="102400000"/>
|
||
<!--单个文件最大限制-->
|
||
<property name="maxUploadSizePerFile" value="10240000"/>
|
||
<property name="defaultEncoding" value="utf-8"/>
|
||
</bean>
|
||
```
|
||
|
||
2.新建测试上传的FileController.java
|
||
|
||
```java
|
||
package com.heibaiying.controller;
|
||
|
||
import com.heibaiying.utils.FileUtil;
|
||
import org.apache.commons.io.FileUtils;
|
||
import org.springframework.http.HttpHeaders;
|
||
import org.springframework.http.HttpStatus;
|
||
import org.springframework.http.MediaType;
|
||
import org.springframework.http.ResponseEntity;
|
||
import org.springframework.stereotype.Controller;
|
||
import org.springframework.ui.Model;
|
||
import org.springframework.web.bind.annotation.GetMapping;
|
||
import org.springframework.web.bind.annotation.PostMapping;
|
||
import org.springframework.web.bind.annotation.RequestParam;
|
||
import org.springframework.web.multipart.MultipartFile;
|
||
|
||
import javax.servlet.http.HttpSession;
|
||
import java.io.File;
|
||
import java.io.IOException;
|
||
import java.io.UnsupportedEncodingException;
|
||
import java.net.URLEncoder;
|
||
|
||
/**
|
||
* @author : heibaiying
|
||
* @description : 文件上传
|
||
*/
|
||
|
||
@Controller
|
||
public class FileController {
|
||
|
||
@GetMapping("file")
|
||
public String filePage() {
|
||
return "file";
|
||
}
|
||
|
||
|
||
/***
|
||
* 单文件上传
|
||
*/
|
||
@PostMapping("upFile")
|
||
public String upFile(MultipartFile file, HttpSession session) {
|
||
//保存在项目根目录下image文件夹下，如果文件夹不存在则创建
|
||
FileUtil.saveFile(file, session.getServletContext().getRealPath("/image"));
|
||
// success.jsp 就是一个简单的成功页面
|
||
return "success";
|
||
}
|
||
|
||
/***
|
||
* 多文件上传 多个文件用同一个名字
|
||
*/
|
||
@PostMapping("upFiles")
|
||
public String upFiles(@RequestParam(name = "file") MultipartFile[] files, HttpSession session) {
|
||
for (MultipartFile file : files) {
|
||
FileUtil.saveFile(file, session.getServletContext().getRealPath("images"));
|
||
}
|
||
return "success";
|
||
}
|
||
|
||
/***
|
||
* 多文件上传方式2 分别为不同文件指定不同名字
|
||
*/
|
||
@PostMapping("upFiles2")
|
||
public String upFile(String extendParam,
|
||
@RequestParam(name = "file1") MultipartFile file1,
|
||
@RequestParam(name = "file2") MultipartFile file2, HttpSession session) {
|
||
String realPath = session.getServletContext().getRealPath("images2");
|
||
FileUtil.saveFile(file1, realPath);
|
||
FileUtil.saveFile(file2, realPath);
|
||
System.out.println("extendParam:" + extendParam);
|
||
return "success";
|
||
}
|
||
}
|
||
|
||
```
|
||
|
||
3.其中工具类FileUtil.java代码如下
|
||
|
||
```java
|
||
package com.heibaiying.utils;
|
||
|
||
import org.springframework.web.multipart.MultipartFile;
|
||
import java.io.*;
|
||
|
||
/**
|
||
* @author : heibaiying
|
||
* @description : 文件上传工具类
|
||
*/
|
||
|
||
public class FileUtil {
|
||
|
||
public static String saveFile(MultipartFile file, String path) {
|
||
InputStream inputStream = null;
|
||
FileOutputStream outputStream = null;
|
||
String fullPath = path + File.separator + file.getOriginalFilename();
|
||
try {
|
||
File saveDir = new File(path);
|
||
if (!saveDir.exists()) {
|
||
saveDir.mkdirs();
|
||
}
|
||
outputStream = new FileOutputStream(new File(fullPath));
|
||
inputStream = file.getInputStream();
|
||
byte[] bytes = new byte[1024 * 1024];
|
||
int read;
|
||
while ((read = inputStream.read(bytes)) != -1) {
|
||
outputStream.write(bytes, 0, read);
|
||
}
|
||
} catch (IOException e) {
|
||
e.printStackTrace();
|
||
} finally {
|
||
if (inputStream != null) {
|
||
try {
|
||
inputStream.close();
|
||
} catch (IOException e) {
|
||
e.printStackTrace();
|
||
}
|
||
}
|
||
if (outputStream != null) {
|
||
try {
|
||
outputStream.close();
|
||
} catch (IOException e) {
|
||
e.printStackTrace();
|
||
}
|
||
}
|
||
}
|
||
return fullPath;
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
4.新建用于上传的jsp页面，上传文件时表单必须声明 enctype="multipart/form-data"
|
||
|
||
```jsp
|
||
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
|
||
<html>
|
||
<head>
|
||
<title>文件上传</title>
|
||
<link rel="stylesheet" href="${pageContext.request.contextPath}/css/file.css">
|
||
</head>
|
||
<body>
|
||
|
||
<form action="${pageContext.request.contextPath }/upFile" method="post" enctype="multipart/form-data">
|
||
请选择上传文件：<input name="file" type="file"><br>
|
||
<input type="submit" value="点击上传文件">
|
||
</form>
|
||
|
||
<form action="${pageContext.request.contextPath }/upFiles" method="post" enctype="multipart/form-data">
|
||
请选择上传文件(多选)：<input name="file" type="file" multiple><br>
|
||
<input type="submit" value="点击上传文件">
|
||
</form>
|
||
|
||
<form action="${pageContext.request.contextPath }/upFiles2" method="post" enctype="multipart/form-data">
|
||
请选择上传文件1：<input name="file1" type="file"><br>
|
||
请选择上传文件2：<input name="file2" type="file"><br>
|
||
文件内容额外备注: <input name="extendParam" type="text"><br>
|
||
<input type="submit" value="点击上传文件">
|
||
</form>
|
||
|
||
</body>
|
||
</html>
|
||
|
||
```
|
||
|
||
#### 6.2 文件下载
|
||
|
||
1.在fileController.java中加上方法：
|
||
|
||
```java
|
||
/***
|
||
* 上传用于下载的文件
|
||
*/
|
||
@PostMapping("upFileForDownload")
|
||
public String upFileForDownload(MultipartFile file, HttpSession session, Model model) throws UnsupportedEncodingException {
|
||
String path = FileUtil.saveFile(file, session.getServletContext().getRealPath("/image"));
|
||
model.addAttribute("filePath", URLEncoder.encode(path,"utf-8"));
|
||
model.addAttribute("fileName", file.getOriginalFilename());
|
||
return "fileDownload";
|
||
}
|
||
|
||
/***
|
||
* 下载文件
|
||
*/
|
||
@GetMapping("download")
|
||
public ResponseEntity<byte[]> downloadFile(String filePath) throws IOException {
|
||
HttpHeaders headers = new HttpHeaders();
|
||
File file = new File(filePath);
|
||
// 解决文件名中文乱码
|
||
String fileName=new String(file.getName().getBytes("UTF-8"),"iso-8859-1");
|
||
headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
|
||
headers.setContentDispositionFormData("attachment", fileName);
|
||
|
||
return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),
|
||
headers, HttpStatus.CREATED);
|
||
}
|
||
```
|
||
|
||
2.其中fileDownload.jsp 如下：
|
||
|
||
```jsp
|
||
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
|
||
<html>
|
||
<head>
|
||
<title>文件下载</title>
|
||
</head>
|
||
<body>
|
||
<a href="${pageContext.request.contextPath}/download?filePath=${filePath}">${fileName}</a>
|
||
</body>
|
||
</html>
|
||
```
|
||
|
||
|
||
|
||
## 七、Restful风格的请求
|
||
|
||
1.新建Pet.java实体类
|
||
|
||
```java
|
||
package com.heibaiying.bean;
|
||
|
||
import lombok.Data;
|
||
|
||
/**
|
||
* @author : heibaiying
|
||
* @description :测试restful风格的实体类
|
||
*/
|
||
|
||
@Data
|
||
public class Pet {
|
||
|
||
private String ownerId;
|
||
|
||
private String petId;
|
||
}
|
||
|
||
```
|
||
|
||
2.新建RestfulController.java，用@PathVariable和@ModelAttribute注解进行参数绑定。
|
||
|
||
注： 在REST中，资源通过URL进行识别和定位。REST中的行为是通过HTTP方法定义的。在进行不同行为时对应HTTP方法和Spring注解分别如下：
|
||
|
||
- 创建资源时：POST（PostMapping）
|
||
- 读取资源时：GET（ @GetMapping）
|
||
- 更新资源时：PUT或PATCH（PutMapping、PatchMapping）
|
||
- 删除资源时：DELETE（DeleteMapping）
|
||
|
||
```java
|
||
package com.heibaiying.controller;
|
||
|
||
import com.heibaiying.bean.Pet;
|
||
import org.springframework.validation.annotation.Validated;
|
||
import org.springframework.web.bind.annotation.*;
|
||
|
||
/**
|
||
* @author : heibaiying
|
||
* @description : Restful 风格的请求
|
||
*/
|
||
|
||
@RestController
|
||
public class RestfulController {
|
||
|
||
@GetMapping("restful/owners/{ownerId}/pets/{petId}")
|
||
public void get(@PathVariable String ownerId, @PathVariable String petId) {
|
||
System.out.println("ownerId:" + ownerId);
|
||
System.out.println("petId:" + petId);
|
||
}
|
||
|
||
@GetMapping("restful2/owners/{ownerId}/pets/{petId}")
|
||
public void get(@ModelAttribute Pet pet) {
|
||
System.out.println("ownerId:" + pet.getOwnerId());
|
||
System.out.println("petId:" + pet.getPetId());
|
||
}
|
||
|
||
}
|
||
|
||
```
|
||
|