解決Spring Boot 攔截器注入service為空的問題

問題：在自定義攔截器中，使用了@Autowaire注解注入了封裝JPA方法的Service，結果發現無法注入，注入的service為空

0.原因分析

攔截器加載的時間點在springcontext之前，所以在攔截器中注入自然為null

1.需要在攔截器上加@Component

package com.fdzang.mblog.interceptor;

import com.fdzang.mblog.pojo.*;
import com.fdzang.mblog.service.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.List;
import java.util.Optional;

@Component
public class InitInterceptor implements HandlerInterceptor {
    @Autowired
    OptionsService optionsService;

    @Autowired
    UserService userService;

    @Autowired
    PageService pageService;

    @Autowired
    LabelService labelService;

    @Autowired
    ArticleService articleService;

    @Autowired
    CategoryService categoryService;

    @Autowired
    TagService tagService;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception {
        // TODO Auto-generated method stub
        //controller方法調用之前
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object o, ModelAndView mv)
            throws Exception {
        // TODO Auto-generated method stub
        //請求處理之后進行調用，但是在視圖被渲染之前，即Controller方法調用之后
        HttpServletRequest req = (HttpServletRequest) request;
        HttpSession session=req.getSession();
        String isInited=(String)req.getSession().getAttribute("isInited");
        Optional<String> isInited_op=Optional.ofNullable(isInited);
        if(!isInited_op.isPresent()) {
            List<Options> options = optionsService.findAll();
            List<Page> pageNavigations = pageService.findAll();
            List<Label> labels = labelService.findAll();
            List<Category> mostUsedCategories = categoryService.getMostUsedCategories();
            List<Tag> mostUsedTags = tagService.getMostUsedTags();
            List<Article> mostCommentArticles = articleService.getMostCommentArticles();
            List<Article> mostViewCountArticles = articleService.getMostViewCountArticles();

            User adminUser = null;
            int paginationPageCount = 0;
            session.setAttribute("pageNavigations", pageNavigations);
            for (Options option : options) {
                session.setAttribute(option.getoId(), option.getOptionValue());
                if (option.getoId().equals("adminEmail")) {
                    adminUser = userService.getUserByEmail(option.getOptionValue());
                    session.setAttribute("adminUser", adminUser);
                    System.out.println(adminUser.getUserName());
                }
            }
            for (Label label : labels) {
                session.setAttribute(label.getoId(), label.getZh_cn());
            }
            session.setAttribute("servePath", "localhost:8080");
            session.setAttribute("isLoggedIn", false);
            session.setAttribute("loginURL", "/login");
            session.setAttribute("mostUsedCategories", mostUsedCategories);
            session.setAttribute("mostUsedTags", mostUsedTags);
            session.setAttribute("paginationPageCount", paginationPageCount);
            session.setAttribute("mostCommentArticles", mostCommentArticles);
            session.setAttribute("mostViewCountArticles", mostViewCountArticles);

            session.setAttribute("isInited", "inited");
        }
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object o, Exception e)
            throws Exception {
        //在整個請求結束之后被調用，也就是在DispatcherServlet
        //渲染了對應的視圖之后執行，主要是用於進行資源清理工作
    }
}

 

2.進行攔截器配置

 

package com.fdzang.mblog.config;

import com.fdzang.mblog.interceptor.InitInterceptor;
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.WebMvcConfigurerAdapter;

@Configuration
public class InterceptorConfig extends WebMvcConfigurerAdapter {
    @Bean
    public InitInterceptor myInterceptor(){
        return new InitInterceptor();
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //多個攔截器組成一個攔截器鏈
        // addPathPatterns用於添加攔截規則
        // excludePathPatterns用戶排除攔截
        //對來自/** 全路徑請求進行攔截
        registry.addInterceptor(myInterceptor()).addPathPatterns("/**");
        super.addInterceptors(registry);
    }
}

 

 

參考博客：https://blog.csdn.net/wmh13262227870/article/details/77005920