SpringBoot獲取Spring容器中的Bean
阿新 • • 發佈：2019-02-07
一：實戰背景
無論是採用XML檔案的方式還是JAVA配置的方式。都是配置豆嘛，那麼如何獲取春天容器中的Bean（Spring容器自身的Bean和我們自己配置的Bean）的吶？並且以表格展示一下，統一一下數量吧。
二：環境搭建
SpringBoot框架，Thymeleaf，BootStrap，IDEA，Maven的,Ajax前後臺互動，即可。
三：實驗環節
1.通過ConfigurableApplicationContext這個介面來獲取，繼承ApplicationContext。定義了一些設定上下文，監聽容器，重新整理容器的操作。可以獲取使用了特定註解的Bean，容器裡面所有的Bean的。
原始碼如下：
public interface ConfigurableApplicationContext extends ApplicationContext, Lifecycle, Closeable { String CONFIG_LOCATION_DELIMITERS = ",; \t\n"; String CONVERSION_SERVICE_BEAN_NAME = "conversionService"; String LOAD_TIME_WEAVER_BEAN_NAME = "loadTimeWeaver"; String ENVIRONMENT_BEAN_NAME = "environment"; String SYSTEM_PROPERTIES_BEAN_NAME = "systemProperties"; String SYSTEM_ENVIRONMENT_BEAN_NAME = "systemEnvironment"; void setId(String var1); void setParent(ApplicationContext var1); void setEnvironment(ConfigurableEnvironment var1); ConfigurableEnvironment getEnvironment(); void addBeanFactoryPostProcessor(BeanFactoryPostProcessor var1);void addApplicationListener(ApplicationListener<?> var1); void addProtocolResolver(ProtocolResolver var1); void refresh() throws BeansException, IllegalStateException; void registerShutdownHook(); void close(); boolean isActive(); ConfigurableListableBeanFactory getBeanFactory() throws IllegalStateException; }
ContextConfig配置類
import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.context.annotation.Configuration;@Configuration public class ContextConfig { @Autowired private ConfigurableApplicationContext context; public int getCount(){ return context.getBeanDefinitionCount(); } public String[] getContext(){ return context.getBeanDefinitionNames(); } }
BeanController。一個Map存放資料。Ajax接收資料。
import com.lx.myvideo.config.ContextConfig; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import java.util.HashMap; import java.util.Map;@RestController public class BeansController { @Autowired private ContextConfig contextConfig; @RequestMapping("/getBeans") public Map showBeans(){ Map<String,Object> map=new HashMap(); map.put("count",contextConfig.getCount()); return map; } }
PageController
import com.lx.myvideo.config.ContextConfig; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.servlet.ModelAndView;@Controller public class PageController { @Autowired private ContextConfig contextConfig; private static final String TO_PATH="beans"; @RequestMapping("/beans") public ModelAndView showBeans(){ String[] beans=contextConfig.getContext(); ModelAndView view=new ModelAndView(); view.addObject("beansArray",beans); view.setViewName(TO_PATH); return view; } }beans.html（前臺向後臺請求資料（不帶資料），後臺返回給前臺JSON格式的資料，就是Bean的個數嘛。）
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org" > <head> <meta charset="UTF-8"> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org" > <head> <meta charset="UTF-8"> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=Edge，chrome=1"> <title>【獲取Spring容器的Bean】</title> <meta name="keywords" content="Beans"> <meta name="description" content="Beans"> <link rel="icon" th:href="@{/images/newlogo.png}" /> <link rel="stylesheet" th:href="@{/css/bootstrap.min.css}" media="all"> <link rel="stylesheet" th:href="@{/font-awesome/css/font-awesome.min.css}" /> <script th:src="@{/js/jquery-1.7.1.min.js}"></script> <style type="text/css"> *{ margin:0; padding:0; } .beanbtn{ position: relative; left: 737px; top: -54px; } #count{ width:350px; position:relative; left:390px; top:-20px; } #bean{ width:80%; margin: 0 auto; } </style> </head> <body> <div style="width:100%;height:100px;" align="center"> <h1 style="color:#985f0d;">獲取Spring容器中的Bean</h1> </div> <div > <input type="text" class="form-control" id="count" value="" readonly /> <div class="beanbtn"> <button type="button" class="btn btn-primary" id="getBeans">獲取當前容器中的Bean</button> </div> </div> <div class="bs-example" data-example-id="striped-table" id="bean" > <table class="table table-bordered table-hover"> <thead> <tr> <th style="text-align:center;" scope="row">序號</th> <th style="text-align:center;">BeanName</th> </tr> </thead> <tbody> <tr th:each="array:${beansArray}"> <th style="text-align:center;" th:text="${arrayStat.index+1}"></th> <th th:text="${array}"></th> </tr> </tbody> </table> </div> <script> $(function(){ $('#getBeans').click(function(){ $.ajax({ url:'/getBeans', type:'post', data:{}, dataType:'json', success:function(data){ $("#count").val("當前容器中的Bean資料量為："+data.count); }, error:function(data){ alert("獲取資料失敗!"); } }); }); }); </script> </body> </html>
2.細節環節
Thymeleaf在遍歷陣列的時候，比如我這裡是字串[]的陣列，要設計到索引號的問題。有些特殊。在前面的陣列接受後臺的之後加Stat的就可以了。小寫的不可以。要報不識別的錯誤的。
<th style = “ text-align：center ; ” th ：text = “$ {arrayStat.index + 1}” > </ th>
3.執行結果
點選按鈕獲取Bean的資料量。
4.當然了能獲取Bean的名稱和數量，那麼Bean的型別和包名也能獲取。包括@Controller，@Service等都是可以獲取的。
例如獲取@Controller註解類的個數。
MyStringUtil
import org.springframework.beans.BeansException; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.context.annotation.Configuration; import org.springframework.stereotype.Component; import java.lang.annotation.Annotation;@Configuration @Component public class MySpringUtil implements ApplicationContextAware { /** 宣告一個ApplicationContext*/ private static ApplicationContext applicationContext = null; @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { if(MySpringUtil.applicationContext==null){ MySpringUtil.applicationContext=applicationContext; } System.out.println("---獲取到applicationContext---"); } /** 獲取ApplicationContext*/ public static ApplicationContext getApplicationContext(){ return applicationContext; } /** 統計controller的數量*/ public static String[] controllers(Class<? extends Annotation> clazz){ return applicationContext.getBeanNamesForAnnotation(clazz); } }
然後在使用的類裡面依賴注入使用@Autowired型別注入即可。
當時使用了ApplicationContextAware介面來也可以的.