I-o-C 一篇概覽

public interface ApplicationContextAware {
    void setApplicationContext(ApplicationContext applicationContext) throws BeansException;
}

public interface BeanNameAware {

    void setBeanName(String name) throws BeansException;
}

public class MovieRecommender {

    @Autowired
    private ApplicationContext context;

    public MovieRecommender() {
    }

    // ...
}

@Configuration
public class MovieConfiguration {

    @Bean
    @Primary
    public MovieCatalog firstMovieCatalog() { ... }

    @Bean
    public MovieCatalog secondMovieCatalog() { ... }

    // ...
}

。。。

public class MovieRecommender {

    @Autowired
    private MovieCatalog movieCatalog; //firstMovieCatalog

// ... }

public class MovieRecommender {

    @Autowired
    @Qualifier("main")
    private MovieCatalog movieCatalog;

    // ...
}

或

public class MovieRecommender {

    private final MovieCatalog movieCatalog;

    private final CustomerPreferenceDao customerPreferenceDao;

    @Autowired
    public void prepare(@Qualifier("main") MovieCatalog movieCatalog,
            CustomerPreferenceDao customerPreferenceDao) {
        this.movieCatalog = movieCatalog;
        this.customerPreferenceDao = customerPreferenceDao;
    }

    // ...
}

public class SimpleMovieLister {

    private MovieFinder movieFinder;

    @Resource(name="myMovieFinder") 
    public void setMovieFinder(MovieFinder movieFinder) {
        this.movieFinder = movieFinder;
    }
}

catalog.name=MovieCatalog

@Configuration
@PropertySource("classpath:application.properties")
public class AppConfig { }

@Component
public class MovieRecommender {

    private final String catalog;

    public MovieRecommender(@Value("${catalog.name}") String catalog) {
        this.catalog = catalog;
    }
}

public static void main(String[] args) {
    ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig.class);
    MyService myService = ctx.getBean(MyService.class);
    myService.doStuff();
}　

//

public static void main(String[] args) {
    ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig.class);
    MyService myService = ctx.getBean(MyService.class);
    myService.doStuff();
}　　

public static void main(String[] args) {
    AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
    ctx.register(AppConfig.class, OtherConfig.class);
    ctx.register(AdditionalConfig.class);
    ctx.refresh();
    MyService myService = ctx.getBean(MyService.class);
    myService.doStuff();
}

@Configuration
@ComponentScan(basePackages = "com.acme") (1)
public class AppConfig  {
    // ...
}

// 或

<beans>
    <context:component-scan base-package="com.acme"/>
</beans>

public static void main(String[] args) {
    AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
    ctx.scan("com.acme");
    ctx.refresh();
    MyService myService = ctx.getBean(MyService.class);
}

public interface BaseConfig {

    @Bean
    default TransferServiceImpl transferService() {
        return new TransferServiceImpl();
    }
}

@Configuration
public class AppConfig implements BaseConfig {

}

@Configuration
public class AppConfig {

    @Bean
    public TransferService transferService(AccountRepository accountRepository) {
        return new TransferServiceImpl(accountRepository);
    }
}　

public class BeanOne {

    public void init() {
        // initialization logic
    }
}

public class BeanTwo {

    public void cleanup() {
        // destruction logic
    }
}

@Configuration
public class AppConfig {

    @Bean(initMethod = "init")
    public BeanOne beanOne() {
        return new BeanOne();
    }

    @Bean(destroyMethod = "cleanup")
    public BeanTwo beanTwo() {
        return new BeanTwo();
    }
}

@Configuration
public class MyConfiguration {

    @Bean
    @Scope("prototype")
    public Encryptor encryptor() {
        // ...
    }
}　

@Configuration
public class MyConfiguration {

    @Bean
    @Scope(proxyMode = ScopedProxyMode.INTERFACES)
    public Encryptor encryptor() {
        // ...
    }
}

@Configuration
public class AppConfig {

    @Bean("myThing")
    public Thing thing() {
        return new Thing();
    }
}

//

@Configuration
public class AppConfig {

    @Bean({"dataSource", "subsystemA-dataSource", "subsystemB-dataSource"})
    public DataSource dataSource() {
        // instantiate, configure and return DataSource bean...
    }
}

@Configuration
public class AppConfig {

    @Bean
    public ClientService clientService1() {
        ClientServiceImpl clientService = new ClientServiceImpl();
        clientService.setClientDao(clientDao());
        return clientService;
    }

    @Bean
    public ClientService clientService2() {
        ClientServiceImpl clientService = new ClientServiceImpl();
        clientService.setClientDao(clientDao());
        return clientService;
    }

    @Bean
    public ClientDao clientDao() {
        return new ClientDaoImpl();
    }
}

public abstract class CommandManager {
    public Object process(Object commandState) {
        // grab a new instance of the appropriate Command interface
        Command command = createCommand();
        // set the state on the (hopefully brand new) Command instance
        command.setState(commandState);
        return command.execute();
    }

    // okay... but where is the implementation of this method?
    protected abstract Command createCommand();
}

//

@Bean
@Scope("prototype")
public AsyncCommand asyncCommand() {
    AsyncCommand command = new AsyncCommand();
    // inject dependencies here as required
    return command;
}

@Bean
public CommandManager commandManager() {
    // return new anonymous implementation of CommandManager with createCommand()
    // overridden to return a new prototype Command object
    return new CommandManager() {
        protected Command createCommand() {
            return asyncCommand();
        }
    }
}

@Configuration
public class ConfigA {

    @Bean
    public A a() {
        return new A();
    }
}

//

@Configuration
@Import(ConfigA.class)
public class ConfigB {

    @Bean
    public B b() {
        return new B();
    }
}

public static void main(String[] args) {
    ApplicationContext ctx = new AnnotationConfigApplicationContext(ConfigB.class);

    // now both beans A and B will be available...
    A a = ctx.getBean(A.class);
    B b = ctx.getBean(B.class);
}　　

-Dspring.profiles.active="profile1,profile2"　　　 

ApplicationContext ctx = new GenericApplicationContext();
Environment env = ctx.getEnvironment();
boolean containsMyProperty = env.containsProperty("my-property");
System.out.println("Does my environment contain the 'my-property' property? " + containsMyProperty);

ConfigurableApplicationContext ctx = new GenericApplicationContext();
MutablePropertySources sources = ctx.getEnvironment().getPropertySources();
sources.addFirst(new MyPropertySource());

testbean.name=myTestBean

@Configuration
@PropertySource("classpath:/com/myco/app.properties")
public class AppConfig {

    @Autowired
    Environment env;

    @Bean
    public TestBean testBean() {
        TestBean testBean = new TestBean();
        testBean.setName(env.getProperty("testbean.name"));
        return testBean;
    }
}

@Configuration
@PropertySource("classpath:/com/${my.placeholder:default/path}/app.properties")
public class AppConfig {

    @Autowired
    Environment env;

    @Bean
    public TestBean testBean() {
        TestBean testBean = new TestBean();
        testBean.setName(env.getProperty("testbean.name"));
        return testBean;
    }
}

public final class Locale implements Cloneable, Serializable {

    static private final  Cache LOCALECACHE = new Cache();

    /** Useful constant for language.
     */
    static public final Locale ENGLISH = createConstant("en", "");

    /** Useful constant for language.
     */
    static public final Locale JAPANESE = createConstant("ja", "");

    /** Useful constant for language.
     */
    static public final Locale CHINESE = createConstant("zh", "");

    /** Useful constant for language.
     */
    static public final Locale SIMPLIFIED_CHINESE = createConstant("zh", "CN");

    /** Useful constant for language.
     */
    static public final Locale TRADITIONAL_CHINESE = createConstant("zh", "TW");

... ...

public class BlockedListEvent extends ApplicationEvent {

    private final String address;
    private final String content;

    public BlockedListEvent(Object source, String address, String content) {
        super(source);
        this.address = address;
        this.content = content;
    }

    // accessor and other methods...
}　　

public class EmailService implements ApplicationEventPublisherAware {

    private List<String> blockedList;
    private ApplicationEventPublisher publisher;

    public void setBlockedList(List<String> blockedList) {
        this.blockedList = blockedList;
    }

    public void setApplicationEventPublisher(ApplicationEventPublisher publisher) {
        this.publisher = publisher;
    }

    public void sendEmail(String address, String content) {
        if (blockedList.contains(address)) {
            publisher.publishEvent(new BlockedListEvent(this, address, content));
            return;
        }
        // send email...
    }
}　

public class BlockedListNotifier implements ApplicationListener<BlockedListEvent> {

    private String notificationAddress;

    public void setNotificationAddress(String notificationAddress) {
        this.notificationAddress = notificationAddress;
    }

    public void onApplicationEvent(BlockedListEvent event) {
        // notify appropriate parties via notificationAddress...
    }
}

public class BlockedListNotifier {

    private String notificationAddress;

    public void setNotificationAddress(String notificationAddress) {
        this.notificationAddress = notificationAddress;
    }

    @EventListener
    public void processBlockedListEvent(BlockedListEvent event) {
        // notify appropriate parties via notificationAddress...
    }
}

@EventListener
@Async
public void processBlockedListEvent(BlockedListEvent event) {
    // BlockedListEvent is processed in a separate thread
}

@EventListener
@Order(42)
public void processBlockedListEvent(BlockedListEvent event) {
    // notify appropriate parties via notificationAddress...
}

.setApplicationStartup(new MyApplicationStartup())