提供项目说明
This commit is contained in:
luoxiang
parent
c3428d4056
commit
51e22340af
@ -0,0 +1,372 @@
|
||||
# springmvc基础（基于注解）
|
||||
|
||||
**开发环境：IDEA**
|
||||
|
||||
**spring版本：5.1.3.RELEASE**
|
||||
|
||||
**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)**
|
||||
|
||||
## 一、搭建hello spring工程
|
||||
|
||||
### 1.1 项目搭建
|
||||
|
||||
1.新建maven web工程，并引入相应的依赖
|
||||
|
||||
```xml
|
||||
<properties>
|
||||
<spring-base-version>5.1.3.RELEASE</spring-base-version>
|
||||
</properties>
|
||||
|
||||
<dependencies>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-context</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-beans</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-core</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-web</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-webmvc</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>javax.servlet</groupId>
|
||||
<artifactId>javax.servlet-api</artifactId>
|
||||
<version>4.0.1</version>
|
||||
<scope>provided</scope>
|
||||
</dependency>
|
||||
</dependencies>
|
||||
```
|
||||
|
||||
2.得益于servlet3.0和spring的支持，我们可以在没有web.xml的情况下完成关于servlet配置。
|
||||
|
||||
新建DispatcherServletInitializer.java文件,这个类的作用相当于我们在xml方式下web.xml中配置的DispatcherServlet
|
||||
|
||||
```java
|
||||
package com.heibaiying.config;
|
||||
|
||||
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
*/
|
||||
|
||||
public class DispatcherServletInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
|
||||
|
||||
protected Class<?>[] getRootConfigClasses() {
|
||||
return new Class[0];
|
||||
}
|
||||
|
||||
protected Class<?>[] getServletConfigClasses() {
|
||||
return new Class[]{ServletConfig.class};
|
||||
}
|
||||
|
||||
protected String[] getServletMappings() {
|
||||
return new String[]{"/"};
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
3.新建ServletConfig.java，文件内容如下(这个类相当于我们在xml配置方式中的springApplication.xml)
|
||||
|
||||
```java
|
||||
package com.heibaiying.config;
|
||||
|
||||
import com.heibaiying.exception.NoAuthExceptionResolver;
|
||||
import com.heibaiying.interceptors.MyFirstInterceptor;
|
||||
import com.heibaiying.interceptors.MySecondInterceptor;
|
||||
import org.springframework.context.annotation.Bean;
|
||||
import org.springframework.context.annotation.ComponentScan;
|
||||
import org.springframework.context.annotation.Configuration;
|
||||
import org.springframework.web.servlet.HandlerExceptionResolver;
|
||||
import org.springframework.web.servlet.ViewResolver;
|
||||
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
|
||||
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
|
||||
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
|
||||
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
|
||||
import org.springframework.web.servlet.view.InternalResourceViewResolver;
|
||||
|
||||
import java.util.List;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
*/
|
||||
@Configuration
|
||||
@EnableWebMvc
|
||||
@ComponentScan(basePackages = {"com.heibaiying.controller"})
|
||||
public class ServletConfig implements WebMvcConfigurer {
|
||||
|
||||
/**
|
||||
* 配置视图解析器
|
||||
*/
|
||||
@Bean
|
||||
public ViewResolver viewResolver() {
|
||||
InternalResourceViewResolver internalResourceViewResolver = new InternalResourceViewResolver();
|
||||
internalResourceViewResolver.setPrefix("/WEB-INF/jsp/");
|
||||
internalResourceViewResolver.setSuffix(".jsp");
|
||||
internalResourceViewResolver.setExposeContextBeansAsAttributes(true);
|
||||
return internalResourceViewResolver;
|
||||
}
|
||||
|
||||
/**
|
||||
* 配置静态资源处理器
|
||||
*/
|
||||
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
|
||||
configurer.enable();
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
4.在src 下新建controller用于测试
|
||||
|
||||
```java
|
||||
package com.heibaiying.controller;
|
||||
|
||||
import com.heibaiying.exception.NoAuthException;
|
||||
import org.springframework.stereotype.Controller;
|
||||
import org.springframework.web.bind.annotation.RequestMapping;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : hello spring
|
||||
*/
|
||||
|
||||
@Controller
|
||||
@RequestMapping("mvc")
|
||||
public class HelloController {
|
||||
|
||||
@RequestMapping("hello")
|
||||
private String hello() {
|
||||
return "hello";
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
5.在WEB-INF 下新建jsp文件夹，新建hello.jsp 文件
|
||||
|
||||
```jsp
|
||||
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
|
||||
<html>
|
||||
<head>
|
||||
<title>Title</title>
|
||||
</head>
|
||||
<body>
|
||||
Hello Spring MVC!
|
||||
</body>
|
||||
</html>
|
||||
```
|
||||
|
||||
6.启动tomcat服务，访问localhost:8080/mvc/hello
|
||||
|
||||
### 1.2 相关注解说明
|
||||
|
||||
**1.@Configuration**
|
||||
|
||||
@Configuration用于定义配置类，可替换xml配置文件，被注解的类内部包含有一个或多个被@Bean注解的方法，这些方法将会被AnnotationConfigApplicationContext或AnnotationConfigWebApplicationContext类进行扫描，并用于构建bean定义，初始化Spring容器。
|
||||
|
||||
**2.@EnableWebMvc**
|
||||
|
||||
简单的说就是提供了部分springmvc的功能，例如格式转换和参数绑定。
|
||||
|
||||
|
||||
|
||||
## 二、配置自定义拦截器
|
||||
|
||||
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）
|
||||
|
||||
```java
|
||||
package com.heibaiying.interceptors;
|
||||
|
||||
import org.springframework.web.servlet.HandlerInterceptor;
|
||||
import org.springframework.web.servlet.ModelAndView;
|
||||
|
||||
import javax.servlet.http.HttpServletRequest;
|
||||
import javax.servlet.http.HttpServletResponse;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : spring5 中 preHandle，postHandle，afterCompletion 在接口中被声明为默认方法
|
||||
*/
|
||||
public class MyFirstInterceptor implements HandlerInterceptor {
|
||||
|
||||
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
|
||||
System.out.println("进入第一个拦截器preHandle");
|
||||
return true;
|
||||
}
|
||||
|
||||
// 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
|
||||
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
|
||||
System.out.println("进入第一个拦截器postHandle");
|
||||
}
|
||||
|
||||
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
|
||||
System.out.println("进入第一个拦截器afterCompletion");
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
```java
|
||||
package com.heibaiying.interceptors;
|
||||
|
||||
import org.springframework.web.servlet.HandlerInterceptor;
|
||||
import org.springframework.web.servlet.ModelAndView;
|
||||
|
||||
import javax.servlet.http.HttpServletRequest;
|
||||
import javax.servlet.http.HttpServletResponse;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : spring5 中 preHandle，postHandle，afterCompletion 在接口中被声明为默认方法
|
||||
*/
|
||||
public class MySecondInterceptor implements HandlerInterceptor {
|
||||
|
||||
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
|
||||
System.out.println("进入第二个拦截器preHandle");
|
||||
return true;
|
||||
}
|
||||
|
||||
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
|
||||
System.out.println("进入第二个拦截器postHandle");
|
||||
}
|
||||
|
||||
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
|
||||
System.out.println("进入第二个拦截器afterCompletion");
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
2.在ServletConfig.java中注册自定义拦截器
|
||||
|
||||
```java
|
||||
/**
|
||||
* 添加自定义拦截器
|
||||
*/
|
||||
public void addInterceptors(InterceptorRegistry registry) {
|
||||
registry.addInterceptor(new MyFirstInterceptor()).addPathPatterns("/mvc/**").excludePathPatterns("mvc/login");
|
||||
registry.addInterceptor(new MySecondInterceptor()).addPathPatterns("/mvc/**");
|
||||
}
|
||||
```
|
||||
|
||||
3.关于多个拦截器方法执行顺序的说明
|
||||
|
||||
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。
|
||||
|
||||
|
||||
|
||||
## 三、全局异常处理
|
||||
|
||||
1.定义自定义异常
|
||||
|
||||
```java
|
||||
package com.heibaiying.exception;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : 自定义无权限异常
|
||||
*/
|
||||
public class NoAuthException extends RuntimeException {
|
||||
|
||||
public NoAuthException() {
|
||||
super();
|
||||
}
|
||||
|
||||
public NoAuthException(String message) {
|
||||
super(message);
|
||||
}
|
||||
|
||||
public NoAuthException(String message, Throwable cause) {
|
||||
super(message, cause);
|
||||
}
|
||||
|
||||
public NoAuthException(Throwable cause) {
|
||||
super(cause);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
2.实现自定义异常处理器
|
||||
|
||||
```java
|
||||
package com.heibaiying.exception;
|
||||
|
||||
import org.springframework.web.servlet.HandlerExceptionResolver;
|
||||
import org.springframework.web.servlet.ModelAndView;
|
||||
|
||||
import javax.servlet.http.HttpServletRequest;
|
||||
import javax.servlet.http.HttpServletResponse;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : 无权限异常处理机制
|
||||
*/
|
||||
public class NoAuthExceptionResolver implements HandlerExceptionResolver {
|
||||
|
||||
public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
|
||||
if (ex instanceof NoAuthException && !isAjax(request)) {
|
||||
return new ModelAndView("NoAuthPage");
|
||||
}
|
||||
return new ModelAndView();
|
||||
}
|
||||
|
||||
// 判断是否是Ajax请求
|
||||
private boolean isAjax(HttpServletRequest request) {
|
||||
return "XMLHttpRequest".equalsIgnoreCase(request.getHeader("X-Requested-With"));
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
3.在ServletConfig.java注册自定义异常处理器
|
||||
|
||||
```java
|
||||
/**
|
||||
* 添加全局异常处理器
|
||||
*/
|
||||
public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
|
||||
resolvers.add(new NoAuthExceptionResolver());
|
||||
}
|
||||
```
|
||||
|
||||
4.定义测试controller，抛出自定义异常
|
||||
|
||||
```java
|
||||
@Controller
|
||||
@RequestMapping("mvc")
|
||||
public class HelloController {
|
||||
|
||||
@RequestMapping("hello")
|
||||
private String hello() {
|
||||
return "hello";
|
||||
}
|
||||
|
||||
|
||||
@RequestMapping("auth")
|
||||
private void auth() {
|
||||
throw new NoAuthException("没有对应的访问权限！");
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
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
|
||||
@ -1 +1,364 @@
|
||||
springmvc-base
|
||||
# springmvc基础（基于xml配置）
|
||||
|
||||
**开发环境：IDEA**
|
||||
|
||||
**spring版本：5.1.3.RELEASE**
|
||||
|
||||
**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)**
|
||||
|
||||
## 一、搭建hello spring工程
|
||||
|
||||
### 1.1 项目搭建
|
||||
|
||||
1.新建maven web工程，并引入相应的依赖
|
||||
|
||||
```xml
|
||||
<properties>
|
||||
<spring-base-version>5.1.3.RELEASE</spring-base-version>
|
||||
</properties>
|
||||
|
||||
<dependencies>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-context</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-beans</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-core</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-web</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework</groupId>
|
||||
<artifactId>spring-webmvc</artifactId>
|
||||
<version>${spring-base-version}</version>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>javax.servlet</groupId>
|
||||
<artifactId>javax.servlet-api</artifactId>
|
||||
<version>4.0.1</version>
|
||||
<scope>provided</scope>
|
||||
</dependency>
|
||||
</dependencies>
|
||||
```
|
||||
|
||||
2.配置web.xml
|
||||
|
||||
```xml
|
||||
<?xml version="1.0" encoding="UTF-8"?>
|
||||
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
|
||||
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
|
||||
http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
|
||||
version="3.1">
|
||||
|
||||
<!--配置spring前端控制器-->
|
||||
<servlet>
|
||||
<servlet-name>springMvc</servlet-name>
|
||||
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
|
||||
<init-param>
|
||||
<param-name>contextConfigLocation</param-name>
|
||||
<param-value>classpath:springApplication.xml</param-value>
|
||||
</init-param>
|
||||
<load-on-startup>1</load-on-startup>
|
||||
</servlet>
|
||||
|
||||
<servlet-mapping>
|
||||
<servlet-name>springMvc</servlet-name>
|
||||
<url-pattern>/</url-pattern>
|
||||
</servlet-mapping>
|
||||
|
||||
</web-app>
|
||||
```
|
||||
|
||||
3.在resources下新建springApplication.xml文件，文件内容如下:
|
||||
|
||||
```xml
|
||||
<?xml version="1.0" encoding="UTF-8"?>
|
||||
<beans xmlns="http://www.springframework.org/schema/beans"
|
||||
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||
xmlns:context="http://www.springframework.org/schema/context"
|
||||
xmlns:mvc="http://www.springframework.org/schema/mvc"
|
||||
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
|
||||
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
|
||||
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
|
||||
|
||||
<!-- 开启注解包扫描-->
|
||||
<context:component-scan base-package="com.heibaiying.*"/>
|
||||
|
||||
<!--使用默认的Servlet来响应静态文件 详见 1.2 -->
|
||||
<mvc:default-servlet-handler/>
|
||||
|
||||
<!-- 开启注解驱动 详见 1.2 -->
|
||||
<mvc:annotation-driven/>
|
||||
|
||||
<!-- 配置视图解析器 -->
|
||||
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
|
||||
id="internalResourceViewResolver">
|
||||
<!-- 前缀 -->
|
||||
<property name="prefix" value="/WEB-INF/jsp/"/>
|
||||
<!-- 后缀 -->
|
||||
<property name="suffix" value=".jsp"/>
|
||||
</bean>
|
||||
|
||||
</beans>
|
||||
```
|
||||
|
||||
4.在src 下新建controller用于测试
|
||||
|
||||
```java
|
||||
package com.heibaiying.controller;
|
||||
|
||||
import com.heibaiying.exception.NoAuthException;
|
||||
import org.springframework.stereotype.Controller;
|
||||
import org.springframework.web.bind.annotation.RequestMapping;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : hello spring
|
||||
*/
|
||||
|
||||
@Controller
|
||||
@RequestMapping("mvc")
|
||||
public class HelloController {
|
||||
|
||||
@RequestMapping("hello")
|
||||
private String hello() {
|
||||
return "hello";
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
5.在WEB-INF 下新建jsp文件夹，新建hello.jsp 文件
|
||||
|
||||
```jsp
|
||||
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
|
||||
<html>
|
||||
<head>
|
||||
<title>Title</title>
|
||||
</head>
|
||||
<body>
|
||||
Hello Spring MVC!
|
||||
</body>
|
||||
</html>
|
||||
```
|
||||
|
||||
6.启动tomcat服务，访问localhost:8080/mvc/hello
|
||||
|
||||
### 1.2 相关配置讲解
|
||||
|
||||
**1.\<mvc:default-servlet-handler/>**
|
||||
|
||||
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：
|
||||
|
||||
- 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。
|
||||
|
||||
- 配置\<mvc:resources /> ：指定静态资源的位置和路径映射：
|
||||
|
||||
```xml
|
||||
<mvc:resources location="/img/" mapping="/img/**"/>
|
||||
<mvc:resources location="/js/" mapping="/js/**"/>
|
||||
<mvc:resources location="/css/" mapping="/css/**"/>
|
||||
```
|
||||
|
||||
**2.\<mvc:annotation-driven/>**
|
||||
|
||||
<mvc:annotation-driven /> 会自动注册DefaultAnnotationHandlerMapping与AnnotationMethodHandlerAdapter
|
||||
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。
|
||||
|
||||
|
||||
|
||||
## 二、配置自定义拦截器
|
||||
|
||||
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）
|
||||
|
||||
```java
|
||||
package com.heibaiying.interceptors;
|
||||
|
||||
import org.springframework.web.servlet.HandlerInterceptor;
|
||||
import org.springframework.web.servlet.ModelAndView;
|
||||
|
||||
import javax.servlet.http.HttpServletRequest;
|
||||
import javax.servlet.http.HttpServletResponse;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : spring5 中 preHandle，postHandle，afterCompletion 在接口中被声明为默认方法
|
||||
*/
|
||||
public class MyFirstInterceptor implements HandlerInterceptor {
|
||||
|
||||
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
|
||||
System.out.println("进入第一个拦截器preHandle");
|
||||
return true;
|
||||
}
|
||||
|
||||
// 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
|
||||
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
|
||||
System.out.println("进入第一个拦截器postHandle");
|
||||
}
|
||||
|
||||
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
|
||||
System.out.println("进入第一个拦截器afterCompletion");
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
```java
|
||||
package com.heibaiying.interceptors;
|
||||
|
||||
import org.springframework.web.servlet.HandlerInterceptor;
|
||||
import org.springframework.web.servlet.ModelAndView;
|
||||
|
||||
import javax.servlet.http.HttpServletRequest;
|
||||
import javax.servlet.http.HttpServletResponse;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : spring5 中 preHandle，postHandle，afterCompletion 在接口中被声明为默认方法
|
||||
*/
|
||||
public class MySecondInterceptor implements HandlerInterceptor {
|
||||
|
||||
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
|
||||
System.out.println("进入第二个拦截器preHandle");
|
||||
return true;
|
||||
}
|
||||
|
||||
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
|
||||
System.out.println("进入第二个拦截器postHandle");
|
||||
}
|
||||
|
||||
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
|
||||
System.out.println("进入第二个拦截器afterCompletion");
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
2.在springApplication.xml中注册自定义拦截器
|
||||
|
||||
```xml
|
||||
<!--配置拦截器-->
|
||||
<mvc:interceptors>
|
||||
<mvc:interceptor>
|
||||
<mvc:mapping path="/mvc/**"/>
|
||||
<mvc:exclude-mapping path="/mvc/login"/>
|
||||
<bean class="com.heibaiying.interceptors.MyFirstInterceptor"/>
|
||||
</mvc:interceptor>
|
||||
<mvc:interceptor>
|
||||
<mvc:mapping path="/mvc/**"/>
|
||||
<bean class="com.heibaiying.interceptors.MySecondInterceptor"/>
|
||||
</mvc:interceptor>
|
||||
</mvc:interceptors>
|
||||
```
|
||||
|
||||
3.关于多个拦截器方法执行顺序的说明
|
||||
|
||||
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。
|
||||
|
||||
|
||||
|
||||
## 三、全局异常处理
|
||||
|
||||
1.定义自定义异常
|
||||
|
||||
```java
|
||||
package com.heibaiying.exception;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : 自定义无权限异常
|
||||
*/
|
||||
public class NoAuthException extends RuntimeException {
|
||||
|
||||
public NoAuthException() {
|
||||
super();
|
||||
}
|
||||
|
||||
public NoAuthException(String message) {
|
||||
super(message);
|
||||
}
|
||||
|
||||
public NoAuthException(String message, Throwable cause) {
|
||||
super(message, cause);
|
||||
}
|
||||
|
||||
public NoAuthException(Throwable cause) {
|
||||
super(cause);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
2.实现自定义异常处理器
|
||||
|
||||
```java
|
||||
package com.heibaiying.exception;
|
||||
|
||||
import org.springframework.web.servlet.HandlerExceptionResolver;
|
||||
import org.springframework.web.servlet.ModelAndView;
|
||||
|
||||
import javax.servlet.http.HttpServletRequest;
|
||||
import javax.servlet.http.HttpServletResponse;
|
||||
|
||||
/**
|
||||
* @author : heibaiying
|
||||
* @description : 无权限异常处理机制
|
||||
*/
|
||||
public class NoAuthExceptionResolver implements HandlerExceptionResolver {
|
||||
|
||||
public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
|
||||
if (ex instanceof NoAuthException && !isAjax(request)) {
|
||||
return new ModelAndView("NoAuthPage");
|
||||
}
|
||||
return new ModelAndView();
|
||||
}
|
||||
|
||||
// 判断是否是Ajax请求
|
||||
private boolean isAjax(HttpServletRequest request) {
|
||||
return "XMLHttpRequest".equalsIgnoreCase(request.getHeader("X-Requested-With"));
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
3.在springApplication.xml注册自定义异常处理器
|
||||
|
||||
```xml
|
||||
<!--配置全局异常处理器-->
|
||||
<bean class="com.heibaiying.exception.NoAuthExceptionResolver"/>
|
||||
```
|
||||
|
||||
4.定义测试controller，抛出自定义异常
|
||||
|
||||
```java
|
||||
@Controller
|
||||
@RequestMapping("mvc")
|
||||
public class HelloController {
|
||||
|
||||
@RequestMapping("hello")
|
||||
private String hello() {
|
||||
return "hello";
|
||||
}
|
||||
|
||||
|
||||
@RequestMapping("auth")
|
||||
private void auth() {
|
||||
throw new NoAuthException("没有对应的访问权限！");
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
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
|
||||
@ -17,6 +17,7 @@ public class MyFirstInterceptor implements HandlerInterceptor {
|
||||
return true;
|
||||
}
|
||||
|
||||
// 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
|
||||
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
|
||||
System.out.println("进入第一个拦截器postHandle");
|
||||
}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user