java - Spring3 - Autowiring 没有发生。该对象为空

Question

servlet.xml

我正在使用注释而不是在 XML 中创建 bean。

并且我在我的 XML 中添加了“context: annotation-config”

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
    <context:component-scan base-package="com.hemanths.expense.manager"/>
    <mvc:annotation-driven/>
    <tx:annotation-driven/>
    <context:annotation-config />

    <bean id="sessionFactory"
          class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="configLocation" value="WEB-INF/hibernate.cfg.xml"/>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.show_sql">true</prop>
            </props>
        </property>
    </bean>

</beans>

UserDaoImpl.java

package com.hemanths.expense.manager.hibernate.dao.impl;

import com.hemanths.expense.manager.hibernate.dao.UserDao;
import com.hemanths.expense.manager.hibernate.entity.User;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public class UserDaoImpl implements UserDao {
    @Autowired
    private SessionFactory sessionFactory;

    public UserDaoImpl() {
    }

    public UserDaoImpl(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    @Override
    public void addUser(User user) {
        sessionFactory.getCurrentSession().save(user);
    }
}

用户服务.java

package com.hemanths.expense.manager.service.impl;

import com.hemanths.expense.manager.hibernate.dao.UserDao;
import com.hemanths.expense.manager.hibernate.entity.User;
import com.hemanths.expense.manager.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserDao userDao;

    public UserServiceImpl() {
    }

    public UserServiceImpl(UserDao userDao){
        this.userDao = userDao;
    }

    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }

    @Override
    @Transactional
    public void addUser(User user) {
        userDao.addUser(user);
    }

UserServiceImplTest.java

public class UserServiceImplTest {

    @Autowired
    UserService userService;

    @Test
    public void shouldAddUser() {
        User user = new User("firstName", "lastName", new Date(), "M", "username", "password");
        userService.addUser(user);
    }
}

堆栈跟踪

java.lang.NullPointerException
    at com.hemanths.expense.manager.service.impl.UserServiceImplTest.shouldAddUser(UserServiceImplTest.java:18)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)

目录结构

Answer 1

我得到了答案。谢谢@Andrei Stefan。

因为我正在运行测试，所以我必须像下面这样用您的 xml 文件路径注释测试。

@ContextConfiguration(locations = {"classpath:mvc-dispatcher-servlet.xml"})
@RunWith(SpringJUnit4ClassRunner.class)
public class UserServiceImplTest {

@Autowired
UserService userService;

@Test
public void shouldAddUser() {
    User user = new User("firstName", "lastName", new Date(), "M", "username", "password");
    userService.addUser(user);
}
}