Question

我正在尝试制作一个MongoOperations Bean，但无法让它工作。我有几个将连接到数据库的类，我不想将以下代码添加到数据库的每个连接。

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

以上代码有效..

我正在制作一个REST Web服务，我有几个类，每个类都需要写入MongoDb.Collection。

我已经设置了一个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();
    }

然后在mongodboperations类中，我试着像这样自动装配它：

@Autowire MongoOperations mongoOperations2;

mongoOperations2.findAll(MongoLicense.class);

我的错误是它无法创建bean。谁能看到我做错了什么？

下面是堆栈跟踪：

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应用程序上下文中

<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>

然后在你的课程中

@Autowired
MongoTemplate mt;

如何创建MongoOperations Bean？

1 个答案: