使用Resource引入失败，提示空指针错误。使用Autowired可以正常运行

package com.lc.ioc_annotation.demo1;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;

/**
 *
 */

@Component("userService")
public class UserService {
    @Value("米饭")
    private String something;
    //@Autowired
    //@Qualifier("userDao")
    @Resource(name = "userDao")
    private UserDao userDao;

    public String sayHello(String name){
        return "Hello"+name;
    }

    public void eat(){
        System.out.println("eat: "+something);
    }

    public void save(){
        System.out.println("Service 中的保存用户方法。。。");
        userDao.save();
    }
}

信息: Loading XML bean definitions from class path resource [applicationContext.xml]

Service 中的保存用户方法。。。

java.lang.NullPointerException

at com.lc.ioc_annotation.demo1.UserService.save(UserService.java:33)

at com.lc.ioc_annotation.demo1.InnoDemo1.demo3(InnoDemo1.java:30)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.base/java.lang.reflect.Method.invoke(Method.java:564)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)

at org.junit.runners.ParentRunner.run(ParentRunner.java:309)

at org.junit.runner.JUnitCore.run(JUnitCore.java:160)

at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)

at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)

at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)

at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)