SpringBoot攔截器

時間 2019-11-30

原文原文鏈接

在實際開發中，總存在着這樣的場景，好比攔截請求的ip地址，或者在全部的請求都返回相同的數據，若是每個方法都寫出相同數據當然能夠實現，可是隨着項目的變大，重複的代碼會愈來愈多，因此在這種狀況咱們能夠用攔截器來實現。html

最近一直在研究thymeleaf，愈加的感受這個很好用，因此這篇文章也選擇結合這個來使用。java

新建項目，pom文件以下：git

<?xml version="1.0" encoding="UTF-8"?>
<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.dalaoyang</groupId>
    <artifactId>springboot_interceptor</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot_interceptor</name>
    <description>springboot_interceptor</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>net.sourceforge.nekohtml</groupId>
            <artifactId>nekohtml</artifactId>
            <version>1.9.15</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>
複製代碼

新建一個攔截器CommonInterceptor，繼承HandlerInterceptorAdapter。給你們說一下，在繼承HandlerInterceptorAdapter有三個攔截器是常常使用的： 1.preHandle在業務處理器處理請求以前被調用
2.postHandle在業務處理器處理請求執行完成後,生成視圖以前執行 3.afterCompletion在DispatcherServlet徹底處理完請求後被調用web

本文使用的是postHandle，代碼以下：spring

package com.dalaoyang.interceptor;

import org.apache.log4j.Logger;
import org.springframework.stereotype.Component;
import org.springframework.ui.ModelMap;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @author dalaoyang
 * @Description
 * @project springboot_learn
 * @package com.dalaoyang.interceptor
 * @email yangyang@dalaoyang.cn
 * @date 2018/4/27
 */
@Component
public class CommonInterceptor extends HandlerInterceptorAdapter {
    Logger logger = Logger.getLogger(CommonInterceptor.class);



    //preHandle在業務處理器處理請求以前被調用，
    //postHandle在業務處理器處理請求執行完成後,生成視圖以前執行
    //afterCompletion在DispatcherServlet徹底處理完請求後被調用
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
                           ModelAndView modelAndView) throws Exception {
        logger.info("請求ip："+request.getRemoteAddr());
        logger.info("請求的方法："+request.getMethod());
        ModelMap modelMap = modelAndView.getModelMap();
        modelMap.addAttribute("title","dalaoyang");
    }
}
複製代碼

在啓動類繼承WebMvcConfigurerAdapter來爲項目添加攔截器，代碼以下：apache

package com.dalaoyang;

import com.dalaoyang.interceptor.CommonInterceptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@SpringBootApplication
public class SpringbootInterceptorApplication extends WebMvcConfigurerAdapter {

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

    @Autowired
    CommonInterceptor commonInterceptor;

    // 增長攔截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(commonInterceptor);
    }
}
複製代碼

IndexController負責跳轉，代碼以下：springboot

package com.dalaoyang.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * @author dalaoyang
 * @Description
 * @project springboot_learn
 * @package com.dalaaoyang.controller
 * @email yangyang@dalaoyang.cn
 * @date 2018/4/27
 */

@Controller
public class IndexController {

    @RequestMapping("/")
    public String index(Model model){
        model.addAttribute("content","hi , dalaoyang !");
        return "index";
    }
}
複製代碼

在templates下新建index.html，其中content是controller返回的內容，title是在攔截器中返回的內容，代碼以下：bash

<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">

<!DOCTYPE html>
<head>
    <meta charset="UTF-8">
    <title th:text="${title}"></title>
</head>
<body>
<p th:text="${content}"></p>
</body>
</html>
複製代碼

啓動項目，訪問http://localhost:8888/，控制檯以下：app