一、新建BeanUtil類

import lombok.extern.slf4j.Slf4j;import org.springframework.beans.BeansException;import org.springframework.beans.factory.DisposableBean;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationContextAware;import java.util.ArrayList;import java.util.List; @Slf4jpublic class BeanUtil implements ApplicationContextAware, DisposableBean { private static ApplicationContext applicationContext = null; /** * 從靜態(tài)變量applicationContext中取得Bean, 自動(dòng)轉(zhuǎn)型為所賦值對(duì)象的類型. */ public static <T> T getBean(Class<T> requiredType) {if(applicationContext==null){ throw new IllegalStateException('applicaitonContext屬性未注入, 請(qǐng)?jiān)赟pringBoot啟動(dòng)類中注冊(cè)BeanUtil.');}return applicationContext.getBean(requiredType); } @Override public void destroy() {applicationContext = null; } @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {if (BeanUtil.applicationContext != null) { log.warn('BeanUtil中的ApplicationContext被覆蓋, 原有ApplicationContext為:' + BeanUtil.applicationContext);}BeanUtil.applicationContext = applicationContext; }}二、在啟動(dòng)類中注入BeanUtil

@SpringBootApplicationpublic class StartApplication { public static void main(String[] args) {SpringApplication.run(StartApplication.class, args); } @Bean public BeanUtil beanUtil() {return new BeanUtil(); }}三、在Util類中獲取Service

public class MyUtils { public static UserDetails getCurrentUser() {MyUserDetailsService userDetailsService = BeanUtil.getBean(MyUserDetailsService.class);//TODO 調(diào)用service中的方法處理自己的業(yè)務(wù)return null; }}springBoot中普通類直接調(diào)用spring管理的dao.service等bean

在項(xiàng)目中經(jīng)常會(huì)用到一些不是controller和service層的去訪問dao層，或者是普通類訪問service層。

前提：

首先確保dao，serivce全部可以在項(xiàng)目啟動(dòng)的時(shí)候掃描到

編寫一個(gè)工具類，通過工具類去獲取ApplicationContext對(duì)象，然后通過applicationContext對(duì)象去加載spring管理的bean

將該工具類在項(xiàng)目啟動(dòng)類進(jìn)行引入，否則會(huì)報(bào)空指針異常。

具體使用方法如下：

1）編寫工具

package com.bonc.springboot.utils;/* * @desc:提供非SPRING管理類調(diào)用管理類的功能 * 注意在服務(wù)啟動(dòng)的時(shí)候進(jìn)行import,apllication中引入 */import org.springframework.beans.BeansException;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationContextAware;public class SpringUtil implements ApplicationContextAware { private static ApplicationContext applicationContext = null; @Overridepublic void setApplicationContext(ApplicationContext applicationContext) throws BeansException { if(SpringUtil.applicationContext == null){ SpringUtil.applicationContext = applicationContext; } System.out.println('---------------------------------------------------------------------'); System.out.println('========ApplicationContext配置成功,在普通類可以通過調(diào)用SpringUtils.getAppContext()獲取applicationContext對(duì)象,applicationContext='+SpringUtil.applicationContext+'========'); System.out.println('---------------------------------------------------------------------'); } //獲取applicationContext public static ApplicationContext getApplicationContext() { return applicationContext; } //通過name獲取 Bean. public static Object getBean(String name){ return getApplicationContext().getBean(name); }//通過class獲取Bean. public static <T> T getBean(Class<T> clazz){ return getApplicationContext().getBean(clazz); }//通過name,以及Clazz返回指定的Bean public static <T> T getBean(String name,Class<T> clazz){ return getApplicationContext().getBean(name, clazz); }}2）將該工具類，在服務(wù)啟動(dòng)類application 中導(dǎo)入

3）普通類中使用APPlicationContent對(duì)象獲取對(duì)應(yīng)的bean進(jìn)行使用：

ApplicationContext appCtx = SpringUtil.getApplicationContext();public TestDao dao = appCtx.getBean(TestDao.class);

也可寫成

public TestDao dao = SpringUtil.getBean(TestDao.class);

具體測(cè)試如下：

例：比如有一個(gè)請(qǐng)求中調(diào)用了實(shí)體類，實(shí)體類的構(gòu)造方法調(diào)用的dao,進(jìn)行的數(shù)據(jù)庫(kù)的訪問

請(qǐng)求：

//普通類進(jìn)行構(gòu)造的時(shí)候，可以調(diào)用dao 對(duì)象@RequestMapping(value='/testClassQuery')public void testClassQuery(){ TestClassQuery testClassQuery =new TestClassQuery();}

普通類代碼：

** * @Description: 測(cè)試普通類如何調(diào)用mapper */ public class TestClassQuery { ApplicationContext appCtx = SpringUtil.getApplicationContext(); public TestDao dao = appCtx.getBean(TestDao.class); private User user; public User getUser() {return user; } public void setUser(User user) {this.user = user; } public TestClassQuery(){testQuery(); } public void testQuery(){user = dao.queryUser('1'); //通過id獲取值System.out.println(user.toString()); }}

以上為個(gè)人經(jīng)驗(yàn)，希望能給大家一個(gè)參考，也希望大家多多支持好吧啦網(wǎng)。