为什么我不能使用@Inject注入SessionFactory，而@Autowired可以？

时间：2014-04-10 14:09:19

标签： spring dependency-injection autowired inject

我正在编写一个使用Hibernate访问数据库的简单项目。

我有一个名为ContactServiceImpl.java的课程：

package hi;    

import javax.inject.Inject;
...    

@Service
@Transactional
public class ContactServiceImpl implements ContactService {
    @Inject private SessionFactory sessionFactory;
...

我在配置文件中声明了sessionFactory。

...
<bean id="sessionFactory"
    class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"
    p:dataSource-ref="dataSource"
    p:packagesToScan="hi"
    p:hibernateProperties-ref="hibernateProperties" />

<context:component-scan base-package="hi" />
....

但是当程序运行时，会发生以下异常：

SEVERE: Servlet.service() for servlet [jsp] in context with path [/HelloHibernate3] threw exception [java.lang.NullPointerException] with root cause
java.lang.NullPointerException
    at hi.ContactServiceImpl.getSession(ContactServiceImpl.java:60)
    at hi.ContactServiceImpl.getContacts(ContactServiceImpl.java:29)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
...

ContactServiceImpl的第60行是：

return sessionFactory.getCurrentSession();

显示sessionFactory未正确初始化。

BUT

当我将@Inject更改为@Autowired时，一切正常：

...
import org.springframework.beans.factory.annotation.Autowired;

@Service
@Transactional
public class ContactServiceImpl implements ContactService {
    @Autowired private SessionFactory sessionFactory;
...

What is the difference between @Inject and @Autowired in Spring Framework? Which one to use under what condition?声明@Autowired和@Inject在Spring下的工作方式相同。

编辑：

我的pom.xml文件是：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>HelloHibernate3</groupId>
  <artifactId>HelloHibernate3</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  <name>HelloHibernate3</name>
  <description/>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>bean-validator</artifactId>
      <version>3.0-JBoss-4.0.2</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.enterprise.deploy</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.jms</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.management.j2ee</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.eclipse.persistence</groupId>
      <artifactId>javax.persistence</artifactId>
      <version>2.0.0</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.resource</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.security.auth.message</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.security.jacc</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.servlet</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.servlet.jsp</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.servlet.jsp.jstl</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.xml.bind</groupId>
      <artifactId>jaxb-api-osgi</artifactId>
      <version>2.2.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.ws.rs</groupId>
      <artifactId>jsr311-api</artifactId>
      <version>1.1.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish.web</groupId>
      <artifactId>jstl-impl</artifactId>
      <version>1.2</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.mail</groupId>
      <artifactId>mail</artifactId>
      <version>1.4.3</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.xml</groupId>
      <artifactId>webservices-api-osgi</artifactId>
      <version>2.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.jboss.weld</groupId>
      <artifactId>weld-osgi-bundle</artifactId>
      <version>1.0.1-SP3</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.glassfish.web</groupId>
      <artifactId>javax.servlet.jsp.jstl</artifactId>
      <version>1.2.1</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-asm</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-expression</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-instrument</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-instrument-tomcat</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.6.9</version>
    </dependency>
    <dependency>
      <groupId>commons-pool</groupId>
      <artifactId>commons-pool</artifactId>
      <version>1.5.3</version>
    </dependency>
    <dependency>
      <groupId>commons-collections</groupId>
      <artifactId>commons-collections</artifactId>
      <version>3.2</version>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.16</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-orm</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>c3p0</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.1.2</version>
    </dependency>
    <dependency>
      <groupId>commons-dbcp</groupId>
      <artifactId>commons-dbcp</artifactId>
      <version>1.4</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jms</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-oxm</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc-portlet</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-struts</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>commons-httpclient</groupId>
      <artifactId>commons-httpclient</artifactId>
      <version>3.1</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>3.1.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>
    <dependency>
      <groupId>org.testng</groupId>
      <artifactId>testng</artifactId>
      <version>5.10</version>
      <classifier>jdk15</classifier>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-acl</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-aspects</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-cas</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-config</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-core</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-crypto</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-ldap</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-openid</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-remoting</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-taglibs</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-web</artifactId>
      <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.webflow</groupId>
      <artifactId>spring-faces</artifactId>
      <version>2.3.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.webflow</groupId>
      <artifactId>spring-webflow</artifactId>
      <version>2.3.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.webflow</groupId>
      <artifactId>spring-binding</artifactId>
      <version>2.3.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.webflow</groupId>
      <artifactId>spring-js</artifactId>
      <version>2.3.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.webflow</groupId>
      <artifactId>spring-js-resources</artifactId>
      <version>2.3.1.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>ognl</groupId>
      <artifactId>ognl</artifactId>
      <version>2.6.9</version>
    </dependency>
    <dependency>
      <groupId>cglib</groupId>
      <artifactId>cglib</artifactId>
      <version>2.2</version>
    </dependency>
    <dependency>
      <groupId>javassist</groupId>
      <artifactId>javassist</artifactId>
      <version>3.9.0.GA</version>
    </dependency>
    <dependency>
      <groupId>antlr</groupId>
      <artifactId>antlr</artifactId>
      <version>2.7.6</version>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-core</artifactId>
      <version>3.3.2.GA</version>
    </dependency>
    <dependency>
      <groupId>javax.transaction</groupId>
      <artifactId>jta</artifactId>
      <version>1.1</version>
    </dependency>
    <dependency>
      <groupId>net.sf.ehcache</groupId>
      <artifactId>ehcache</artifactId>
      <version>1.2.3</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.5.8</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>1.5.8</version>
    </dependency>
    <dependency>
      <groupId>dom4j</groupId>
      <artifactId>dom4j</artifactId>
      <version>1.6.1</version>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-annotations</artifactId>
      <version>3.4.0.GA</version>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-commons-annotations</artifactId>
      <version>3.1.0.GA</version>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-entitymanager</artifactId>
      <version>3.4.0.GA</version>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-validator</artifactId>
      <version>3.1.0.GA</version>
    </dependency>
    <dependency>
      <groupId>javax.persistence</groupId>
      <artifactId>persistence-api</artifactId>
      <version>1.0</version>
    </dependency>
  </dependencies>
  <build>
    <sourceDirectory>src</sourceDirectory>
    <resources>
      <resource>
        <directory>src</directory>
        <excludes>
          <exclude>**/*.java</exclude>
        </excludes>
      </resource>
    </resources>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>2.3.2</version>
        <configuration>
          <source>1.7</source>
          <target>1.7</target>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-war-plugin</artifactId>
        <version>2.2</version>
        <configuration>
          <warSourceDirectory>${basedir}/WebRoot</warSourceDirectory>
          <version>3.0</version>
          <failOnMissingWebXml>false</failOnMissingWebXml>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

2 个答案:

答案 0 :(得分：1)

据我所知，这种依赖

<dependency>
  <groupId>org.jboss.weld</groupId>
  <artifactId>weld-osgi-bundle</artifactId>
  <version>1.0.1-SP3</version>
  <scope>provided</scope>
</dependency>

在编译时提供包含@Inject的库。但是，由于它提供了<scope>，因此您的应用程序取决于您提供的容器。如果没有，Spring将不会在您的字段上查找@Inject注释。

您有几个选择：

  1. 更改依赖项的<scope>或直接添加javax.inject依赖项。
  2. 更改您的容器，以便它实际上提供该依赖项中包含的那些库。

答案 1 :(得分：0)

如果您在链接here中看到，它声明在pom.xml中包含javax.inject依赖项：

    <dependency>
        <groupId>javax.inject</groupId>
        <artifactId>javax.inject</artifactId>
        <version>1</version>
    </dependency>

加入并检查。

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