如何創建MongoOperations Bean？

Question

我試圖做一個MongoOperations Bean，但無法讓它工作。我有幾個類將連接到數據庫，我不想將以下代碼添加到數據庫的每個連接。

ApplicationContext ctx = new AnnotationConfigApplicationContext(SpringMongoConfig2.class); 
MongoOperations mongoOperation = (MongoOperations) ctx.getBean("mongoTemplate"); 

上面的代碼工程..

我正在做一個REST Web服務，我有幾個班，每個需要寫一個MongoDb.Collection。

我已成立了一個bean配置文件：

@Configuration 
public class SpringMongoConfig2 { 

    @Bean 
    public MongoDbFactory mongoDbFactory2() throws Exception { 
     return new SimpleMongoDbFactory(new MongoClient(), "myDatabase"); 
    } 

    @Bean 
    public MongoTemplate mongoTemplate2() throws Exception { 

     MongoTemplate mongoTemplate = new MongoTemplate(mongoDbFactory2()); 

     return mongoTemplate;  
    } 

    @Bean 
    public MongoOperations mongoOperations2() throws Exception { 
     return mongoTemplate2(); 
    } 

然後在在mongodboperations類我嘗試自動裝配這樣的：

@Autowire MongoOperations mongoOperations2; 

mongoOperations2.findAll(MongoLicense.class); 

我的錯誤是，它不能創建豆。任何人都可以看到我做錯了什麼？

下面是堆棧跟蹤：

type Exception report 

message Request processing failed; nested exception is java.lang.NullPointerException 

description The server encountered an internal error that prevented it from fulfilling this request. 

exception 

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException 
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:943) 
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:822) 
    javax.servlet.http.HttpServlet.service(HttpServlet.java:621) 
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807) 
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728) 
    org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) 
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) 
    no.nlf.rest.CorsFilter.doFilter(CorsFilter.java:27) 
root cause 

java.lang.NullPointerException 
    no.nlf.dal.LicenseController.getAllLicenses(LicenseController.java:30) 
    no.nlf.logic.LicenseLogic.getAllLicenses(LicenseLogic.java:18) 
    no.nlf.rest.RestLicense.licenseList(RestLicense.java:26) 
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
    java.lang.reflect.Method.invoke(Unknown Source) 
    org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:214) 
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) 
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) 
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:748) 
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) 
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) 
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945) 
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876) 
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931) 
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:822) 
    javax.servlet.http.HttpServlet.service(HttpServlet.java:621) 
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807) 
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728) 
    org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) 
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) 
    no.nlf.rest.CorsFilter.doFilter(CorsFilter.java:27) 

Answer 1

在Spring應用程序上下文

<mongo:db-factory id="mongoDbFactory" host="db" port="27017" dbname="dbname" /> 


<bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate"> 
    <constructor-arg name="mongoDbFactory" ref="mongoDbFactory" /> 
</bean> 

，然後在你的類

@Autowired 
MongoTemplate mt;