SpringBoot 拦截器 Interceptor

古城微笑少年丶 2023-06-20 06:21 3阅读 0赞

### SpringBoot 拦截器 Interceptor ###

*  项目目录结构
 *  拦截器
 *  拦截器注册
 *  控制器（便于测试）
 *  控制器（便于测试）
 *  参考资料

# 项目目录结构 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2p4NTIw_size_16_color_FFFFFF_t_70]

# 拦截器 #

拦截器三个方法的详细介绍请看[Spring MVC 学习笔记 7《拦截器（Interceptor）》][Spring MVC _ 7_Interceptor]  
`/demo/src/main/java/com/jerry/demo/interceptor/AuthInterceptor.java`  
定义一个拦截器要实现`HandlerInterceptor`接口

package com.jerry.demo.interceptor;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.springframework.stereotype.Component;
    import org.springframework.web.method.HandlerMethod;
    import org.springframework.web.servlet.HandlerInterceptor;
    
    @Component
    public class AuthInterceptor implements HandlerInterceptor { 
    
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { 
        	// 从 http 请求头中取 token
        	String token = request.getHeader("token");
        	// 如果不是映射到方法直接通过
            if (!(handler instanceof HandlerMethod)) { 
                return true;
            }
            if(token==null||token.equals("")){ 
                // 正式的情况下，此处应当抛出合适的自定义异常;
            	throw new RuntimeException("错误信息JSON字符串");
            }
            
            // 用 token 从 redis 去取相关信息。做后续处理。
            
            return true;
            
        }
    }

# 拦截器注册 #

`/demo/src/main/java/com/jerry/demo/config/WebMvcConfig.java`  
实现 [WebMvcConfigurer][] 接口创建一个配置类。在其中注册我们自己的拦截器 （Since: 3.1）  
继承 [WebMvcConfigurerAdapter][] 的方案，在 spring 5.0 已经不再推荐

package com.jerry.demo.config;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
    import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
    
    import com.jerry.demo.interceptor.AuthInterceptor;
    
    @Configuration
    public class WebMvcConfig implements WebMvcConfigurer { 
    	@Autowired
    	private AuthInterceptor authInterceptor;
    
    	/** * 配置静态资源位置： "项目根目录\src\main\resources\static\" 下的所有文件 */
    	@Override
    	public void addResourceHandlers(ResourceHandlerRegistry registry) { 
    		registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
    	}
    	  
    	/** * 注册拦截器：写好的拦截器需要在这里添加注册才能生效 */
    	@Override
    	public void addInterceptors(InterceptorRegistry registry) { 
    		registry.addInterceptor(authInterceptor)
    		.excludePathPatterns("/", "/static/**") // 排除根路径 和 静态资源 
    		.addPathPatterns("/**"); //拦截所有URL 
    	}
    }

`之前我在控制器用 @Controller注解。 静态资源访问会被拦截，换成 @RestController 就不会了。`  
**http://127.0.0.1/static/html/index.html**

// 有人说 /static/** 排除不了。只能按扩展名来配出静态资源。但我试了都可以。
    .excludePathPatterns("/", "/**/*.html", "/**/*.css", "/**/*.js", "/**/*.png", "/**/*.jpg", "/**/*.jpeg", "/**/*.woff", "/**/*.svg");
    .addPathPatterns("/register", "/login"); // 拦截 "/register", "/login" 两个URL

`对于静态资源默认是否拦截和 SpringBoot版本有关 ，我这里用的是 v2.2.0.M1`

<table> 
 <thead> 
  <tr> 
   <th>版本</th> 
   <th>拦截</th> 
   <th>放行</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>SpringBoot 1.*</td> 
   <td>否</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SpringBoot 2.*</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
 </tbody> 
</table>

# 控制器（便于测试） #

`/demo/src/main/java/com/jerry/demo/controller/HelloController.java`

package com.jerry.demo.controller;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class HelloController { 
    	
    	@RequestMapping("/login")
    	public String login() { 
    		return "login";
    	}
    }

# 控制器（便于测试） #

`/demo/src/main/resources/static/html/index.html`

<!DOCTYPE html>
    <html>
    <head>
    <meta charset="UTF-8">
    <title>index</title>
    <script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
    </head>
    <body>
    	<h1>这里是首页</h1>
    	<span id="login">登录</span>
    </body>
    
    <script type="text/javascript"> $(function(){ $("#login").click(function(){ $.ajax({ type : "POST", url : "http://127.0.0.1/login", data : "name=笨笨", beforeSend: function(request) { request.setRequestHeader("token", "9527666"); }, success : function(data) { alert(data); } }); }); }); </script>
    </html>

# 参考资料 #

[Interface HandlerInterceptor ][Interface HandlerInterceptor]  
[Interface WebMvcConfigurer ][WebMvcConfigurer]  
[Class InterceptorRegistry][]  
[Class InterceptorRegistration][]

[Spring MVC 学习笔记 7《拦截器（Interceptor）》][Spring MVC _ 7_Interceptor]  
[Servlet、Filter、Listener 注册方式演变][Servlet_Filter_Listener]

[SpringBoot 设置跨域支持][SpringBoot]  
[SpringBoot 静态资源访问配置][SpringBoot 1]  
[SpringBoot 请求链接参数忽略大小写][SpringBoot 2]

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[Spring MVC _ 7_Interceptor]: https://blog.csdn.net/jx520/article/details/89892090
[WebMvcConfigurer]: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/servlet/config/annotation/WebMvcConfigurer.html
[WebMvcConfigurerAdapter]: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/servlet/config/annotation/WebMvcConfigurerAdapter.html
[Interface HandlerInterceptor]: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/servlet/HandlerInterceptor.html
[Class InterceptorRegistry]: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/servlet/config/annotation/InterceptorRegistry.html
[Class InterceptorRegistration]: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/servlet/config/annotation/InterceptorRegistration.html
[Servlet_Filter_Listener]: https://blog.csdn.net/jx520/article/details/92638166
[SpringBoot]: https://blog.csdn.net/jx520/article/details/103291541
[SpringBoot 1]: https://blog.csdn.net/jx520/article/details/103273953
[SpringBoot 2]: https://jerryjin.blog.csdn.net/article/details/112548619