这篇文章主要介绍“@Resources, @Inject和@Autowired的区别是什么”，在日常操作中，相信很多人在@Resources, @Inject和@Autowired的区别是什么问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”@Resources, @Inject和@Autowired的区别是什么”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
官方文档里对@Resources的说明：
The @Resource annotation is part of the JSR-250 annotation collection and is packaged with Jakarta EE.
什么是JSR-250呢？访问这个链接：https://id=250https://id=330
注入的优先级：
Match by Type
Match by Qualifier
Match by Name
注意@Inject注入的最高优先级方式为Match by Type，而非@Resource的Match by Name.
任意定义一个待注入的Component：
计算
安全
数据库
网络和加速
企业服务
@Componentpublic class ArbitraryDependency {
private final String label = "Arbitrary Dependency";
public String toString() {
return label;
}}使用@Inject注入：
@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(
loader=AnnotationConfigContextLoader.class,
classes=ApplicationContextTestInjectType.class)public class FieldInjectIntegrationTest {
@Inject
private ArbitraryDependency fieldInjectDependency;
@Test
public void givenInjectAnnotation_WhenOnField_ThenValidDependency(){
assertNotNull(fieldInjectDependency);
assertEquals("Arbitrary Dependency",
fieldInjectDependency.toString());
}}定义一个新的待注入组件：
public class AnotherArbitraryDependency extends ArbitraryDependency {
private final String label = "Another Arbitrary Dependency";
public String toString() {
return label;
}}测试代码：
@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(
loader=AnnotationConfigContextLoader.class,
classes=ApplicationContextTestInjectQualifier.class)public class FieldQualifierInjectIntegrationTest {
@Inject
private ArbitraryDependency defaultDependency;
@Inject
private ArbitraryDependency namedDependency;
@Test
public void givenInjectQualifier_WhenOnField_ThenDefaultFileValid(){
assertNotNull(defaultDependency);
assertEquals("Arbitrary Dependency",
defaultDependency.toString());
}
@Test
public void givenInjectQualifier_WhenOnField_ThenNamedFileValid(){
assertNotNull(defaultDependency);
assertEquals("Another Arbitrary Dependency",
namedDependency.toString());
}}和之前@Resource的第一次试图通过Match by Type注入一样失败，遇到异常：NoUniqueBeanDefinitionException
利用@Qualifier避免这个异常：
@Inject@Qualifier("defaultFile")private ArbitraryDependency defaultDependency;@Inject@Qualifier("namedFile")private ArbitraryDependency namedDependency;public class YetAnotherArbitraryDependency extends ArbitraryDependency {
private final String label = "Yet Another Arbitrary Dependency";
public String toString() {
return label;
}}消费者代码：
@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(
loader=AnnotationConfigContextLoader.class,
classes=ApplicationContextTestInjectName.class)public class FieldByNameInjectIntegrationTest {
@Inject
@Named("yetAnotherFieldInjectDependency")
private ArbitraryDependency yetAnotherFieldInjectDependency;
@Test
public void givenInjectQualifier_WhenSetOnField_ThenDependencyValid(){
assertNotNull(yetAnotherFieldInjectDependency);
assertEquals("Yet Another Arbitrary Dependency",
yetAnotherFieldInjectDependency.toString());
}}application context代码：
@Configurationpublic class ApplicationContextTestInjectName {
@Bean
public ArbitraryDependency yetAnotherFieldInjectDependency() {
ArbitraryDependency yetAnotherFieldInjectDependency =
new YetAnotherArbitraryDependency();
return yetAnotherFieldInjectDependency;
}}到此，关于“@Resources, @Inject和@Autowired的区别是什么”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注亿速云网站，小编会继续努力为大家带来更多实用的文章！
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原文链接：http://blog.itpub.net/24475491/viewspace-2688370/
