Spring boot 集成三种拦截方式

三种拦截方式分别为：

  javax.servlet.Filter
  org.springframework.web.servlet.HandlerInterceptor
  org.aspectj.lang.annotation.Aspect

拦截先后顺序

客户端请求 --》 Filter  --》 HandlerInterceptor  --》  Aspect  --》 目标方法  --》 Aspect  --》 HandlerInterceptor --》 Filter --》 客户端

示例如下：

1.   新建Maven项目  interceptor

2.   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/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>
    <groupId>com.java</groupId>
    <artifactId>interceptor</artifactId>
    <version>1.0.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
    </parent>

    <dependencies>

        <!-- Spring Boot -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>

        <!-- 热部署 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>springloaded</artifactId>
            <version>1.2.8.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>

    </dependencies>

    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

3.   InterceptorStarter.java

package com.java;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class InterceptorStarter {

    public static void main(String[] args) {
        SpringApplication.run(InterceptorStarter.class, args);
    }

}

4.   DemoController.java

package com.java.controller;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.Map;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/demo")
public class DemoController {

    @GetMapping("/getHostMessage")
    public Map<String, Object> getHostMessage(String type, String age) {
        Map<String, Object> map = new HashMap<>();

        System.out.println();
        System.out.println("type: " + type);
        System.out.println();

        // 测试异常情况
        if ("exception".equals(type)) {
            throw new RuntimeException("异常演习！");
        }
        try {
            InetAddress serverHost = InetAddress.getLocalHost();
            map.put("hostName", serverHost.getHostName());
            map.put("hostAddress", serverHost.getHostAddress());
            map.put("type", type);
            map.put("age", age);
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }

        return map;
    }

}

5.   DemoFilter.java

package com.java.interceptor;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Component;

/**
 * <blockquote>
 *
 * <pre>
 * 请求拦截过滤器
 *
 * 1. 开启 @Component 注解便可启用拦截功能
 * 2. 不开启 @Component 可通过FilterRegistrationBean 设置注册到 @Configuration 注解的配置类中
 *
 * </pre>
 *
 * </blockquote>
 *
 */
//@Component // 不开启注解时可以通过配置启动
public class DemoFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("初始化DemoFilter");
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        System.out.println(String.format("[ DemoFilter ] [ Into %s ]", req.getRequestURI()));

        chain.doFilter(request, response);

        System.out.println(String.format("[ DemoFilter ] [ Exit %s ]", req.getRequestURI()));
    }

    @Override
    public void destroy() {
        System.out.println("销毁DemoFilter");
    }

}

6.    DemoInterceptor.java

package com.java.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;
import org.springframework.web.servlet.ModelAndView;

@Component
public class DemoInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println(String.format("\n[ DemoInterceptor ] [ Into %s ]", request.getRequestURI()));
        System.out.println("[ preHandle ]");

        System.out.println(((HandlerMethod) handler).getBeanType().getName());
        System.out.println(((HandlerMethod) handler).getMethod().getName());

        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("[ postHandle ] 抛出异常时不执行");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception e) throws Exception {
        System.out.println("[ afterCompletion ]");
        System.out.println("Exception is " + e);

        // 抛出异常时Content-Type为 text/html;charset=ISO-8859-1
        if (null != e) {
            response.setContentType("text/html;charset=UTF-8");
        }

        System.out.println(String.format("[ DemoInterceptor ] [ Exit %s ]\n", request.getRequestURI()));
    }

}

7.   DemoAspect.java

package com.java.interceptor;

import java.util.Arrays;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class DemoAspect {

    @Around("execution(* com.java.controller..*.*(..))")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        System.out.println(String.format("\n[ DemoAspect ] [ Into %s ]", point.getSignature()));

        System.out.println(Arrays.toString(point.getArgs()));
        Object object = point.proceed();

        System.out.println(String.format("[ DemoAspect ] [ Exit %s ]\n", point.getSignature()));
        return object;
    }

    @AfterThrowing(pointcut = "execution(* com.java.controller..*.*(..))", throwing = "e")
    public void afterThrowing(Throwable e) {
        System.out.println(String.format("[ DemoAspect ] %s\n", e));
    }

}

8.   WebConfig.java

package com.java.config;

import javax.servlet.Filter;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import com.java.interceptor.DemoFilter;
import com.java.interceptor.DemoInterceptor;

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private DemoInterceptor demoInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(demoInterceptor);
    }

    @Bean
    public FilterRegistrationBean<Filter> demoFilter() {

        FilterRegistrationBean<Filter> registrationBean = new FilterRegistrationBean<>();

        DemoFilter demoFilter = new DemoFilter();
        registrationBean.setFilter(demoFilter);
        registrationBean.addUrlPatterns("/*");

        return registrationBean;

    }

}

9.   运行InterceptorStarter.java， 启动测试

浏览器输入 http://localhost:8080/demo/getHostMessage?age=16&type=normal

返回结果如下：

{"hostName":"Logan","hostAddress":"192.168.1.101","type":"normal","age":"16"}

查看控制台打印信息如下：

[ DemoFilter ] [ Into /demo/getHostMessage ]

[ DemoInterceptor ] [ Into /demo/getHostMessage ]
[ preHandle ]
com.java.controller.DemoController
getHostMessage

[ DemoAspect ] [ Into Map com.java.controller.DemoController.getHostMessage(String,String) ]
[normal, 16]

type: normal

[ DemoAspect ] [ Exit Map com.java.controller.DemoController.getHostMessage(String,String) ]

[ postHandle ] 抛出异常时不执行
[ afterCompletion ]
Exception is null
[ DemoInterceptor ] [ Exit /demo/getHostMessage ]

[ DemoFilter ] [ Exit /demo/getHostMessage ]

异常场景测试，浏览器输入http://localhost:8080/demo/getHostMessage?age=16&type=exception

返回结果自行研究。

三种拦截功能拦截顺序为：

客户端请求 --》 Filter  --》 HandlerInterceptor  --》  Aspect  --》 目标方法  --》 Aspect  --》 HandlerInterceptor --》 Filter --》 客户端

.