Question

我刚刚开始使用mongodb作为我的新项目的存储库，在我们决定在mongo服务器中设置用户身份验证之前，一切都还可以。

我将spring.config.xml更改为如下连接到具有身份验证的mongo

<bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate">
    <constructor-arg name="mongo" ref="mongo"/>
    <constructor-arg name="databaseName" value="admin"/>
    <constructor-arg name="userCredentials" ref="mongoCredentials"/>
</bean>

<bean id="mongoCredentials" class="org.springframework.data.authentication.UserCredentials">
    <property name="username" value="user" />
    <property name="password" value="password" />
</bean>

<bean class="com.mongodb.MongoURI" id="mongoURI">
    <constructor-arg value="mongodb://localhost:27017"  />
</bean>

<bean class="com.mongodb.Mongo" id="mongo">
    <constructor-arg ref="mongoURI" />
</bean>

这是堆栈跟踪：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoTemplate' defined in class path resource [spring-config.xml]: Cannot resolve reference to bean 'mongoCredentials' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoCredentials' defined in class path resource [spring-config.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.authentication.UserCredentials]: No default constructor found; nested exception is java.lang.NoSuchMethodException: org.springframework.data.authentication.UserCredentials.<init>()
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:359)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:648)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:140)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at com.tosan.test.Test.main(Test.java:27)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoCredentials' defined in class path resource [spring-config.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.authentication.UserCredentials]: No default constructor found; nested exception is java.lang.NoSuchMethodException: org.springframework.data.authentication.UserCredentials.<init>()
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1105)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1050)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)
... 17 more
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.authentication.UserCredentials]: No default constructor found; nested exception is java.lang.NoSuchMethodException: org.springframework.data.authentication.UserCredentials.<init>()
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:85)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1098)
... 25 more
 Caused by: java.lang.NoSuchMethodException: org.springframework.data.authentication.UserCredentials.<init>()
at java.lang.Class.getConstructor0(Class.java:3082)
at java.lang.Class.getDeclaredConstructor(Class.java:2178)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:80)
... 26 more

pom.xml的一部分：

    <properties>
    <spring.version>4.2.4.RELEASE</spring.version>
</properties>
<dependencies>
    <dependency>
        <groupId>com.ibm.icu</groupId>
        <artifactId>icu4j</artifactId>
        <version>57.1</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>${spring.version}</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${spring.version}</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
        <version>${spring.version}</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.data</groupId>
        <artifactId>spring-data-mongodb</artifactId>
        <version>1.8.2.RELEASE</version>
    </dependency>

感谢您的帮助。

Answer 1

试试这个：

<bean id="mongoCredentials" class="org.springframework.data.authentication.UserCredentials">
<constructor-arg value="user"></constructor-arg>
<constructor-arg value="password"></constructor-arg>

你配置它的方式，Spring尝试调用默认构造函数，然后调用setter。但是当然没有默认的构造函数，所以Spring会报告异常

Answer 2

UserCredentials类没有默认构造，它有一个带有以下参数的构造：UserCredentials(String username, String password)。您必须修改bean定义才能使用此构造函数：

<bean id="mongoCredentials" class="org.springframework.data.authentication.UserCredentials">
    <constructor-arg value="user"  />
    <constructor-arg value="password"  />
</bean>

mongodb org.springframework.data.authentication.UserCredentials找不到默认构造函数

2 个答案: