介绍

The Spring Framework provides a comprehensive programming and configuration model for modern Java-based enterprise applications - on any kind of deployment platform. A key element of Spring is infrastructural support at the application level: Spring focuses on the "plumbing" of enterprise applications so that teams can focus on application-level business logic, without unnecessary ties to specific deployment environments.

特性

• Core technologies: dependency injection, events, resources, i18n, validation, data binding, type conversion, SpEL, AOP.
• Testing: mock objects, TestContext framework, Spring MVC Test, WebTestClient.
• Data Access: transactions, DAO support, JDBC, ORM, Marshalling XML.
• Spring MVC and Spring WebFlux web frameworks
• Integration: remoting, JMS, JCA, JMX, email, tasks, scheduling, cache.
• Languages: Kotlin, Groovy, dynamic languages.

Minimum requirements

• JDK 8+ for Spring Framework 5.x
• JDK 6+ for Spring Framework 4.x
• JDK 5+ for Spring Framework 3.x

马上开始

Spring Framework includes a number of different modules. Here we are showing spring-context which provides core functionality. Refer to the getting started guides on the right for other options.

Once you've set up your build with the spring-context dependency, you'll be able to do the following:

hello/MessageService.java

package hello;

public interface MessageService {
    String getMessage();
}

hello/MessagePrinter.java

package hello;

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

@Component
public class MessagePrinter {

    final private MessageService service;

    @Autowired
    public MessagePrinter(MessageService service) {
        this.service = service;
    }

    public void printMessage() {
        System.out.println(this.service.getMessage());
    }
}

hello/Application.java

package hello;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.*;

@Configuration
@ComponentScan
public class Application {

    @Bean
    MessageService mockMessageService() {
        return new MessageService() {
            public String getMessage() {
              return "Hello World!";
            }
        };
    }

  public static void main(String[] args) {
      ApplicationContext context = 
          new AnnotationConfigApplicationContext(Application.class);
      MessagePrinter printer = context.getBean(MessagePrinter.class);
      printer.printMessage();
  }
}

The example above shows the basic concept of dependency injection, the MessagePrinter is decoupled from the MessageService implementation, with Spring Framework wiring everything together.