深入挖掘Spring系列 -- 从设计模式角度看Spring

package org.idea.spring.framework.http.util;
import org.springframework.http.HttpMethod;
import org.springframework.http.client.ClientHttpRequest;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.util.StreamUtils;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
/**
 * @Author linhao
 * @Date created in 9:09 下午 2021/5/22
 */
public class HttpRequestFactoryDemo {
    public static void main(String[] args) throws URISyntaxException, IOException {
        ClientHttpRequestFactory chrf = new SimpleClientHttpRequestFactory();
        ClientHttpRequest clientHttpRequest = chrf.createRequest(new URI("http://www.baidu.com"), HttpMethod.GET);
        ClientHttpResponse clientHttpResponse = clientHttpRequest.execute();
        InputStream inputStream = clientHttpResponse.getBody();
        String response = StreamUtils.copyToString(inputStream, Charset.forName("UTF-8"));
        inputStream.close();
        System.out.println(response);
    }
}
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public class SessionFactory {
    public Session getSession(){
        /** 省略 **/
        return new Session();
    }   
}
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public class SessionFactory {
    public Session getSession(){
        return new Session();
    }
    public RedisSession getRedisSession(){
        return new RedisSession();
    }
    public ZookeeperSession getZookeeperSession(){
        return new ZookeeperSession();
    }
    public WebSocketSession getWebSocketSession(){
        return new WebSocketSession();
    }
}
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public class Session {
    String name;
    public Session(String name) {
        this.name = name;
    }
    @Override
    public String toString() {
        return "Session{" +
                "name='" + name + '\'' +
                '}';
    }
}
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public class ZookeeperSession extends Session {
    public ZookeeperSession(String name){
        super(name);
    }
}
public class WebSocketSession extends Session {
    public WebSocketSession(String name) {
        super(name);
    }
}
public class RedisSession extends Session {
    public RedisSession(String name) {
        super(name);
    }
}
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public interface ISessionFactory {
    Session getSession();
}
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package org.idea.spring.framework.event;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.context.ApplicationListener;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
/**
 * 事件发布器
 *
 * @Author linhao
 * @Date created in 4:47 下午 2021/5/23
 */
public class ApplicationEventPublisherDemo implements ApplicationEventPublisherAware {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext annotationConfigApplicationContext = new AnnotationConfigApplicationContext();
        annotationConfigApplicationContext.register(ApplicationEventPublisherDemo.class);
        annotationConfigApplicationContext.addApplicationListener(new ApplicationListener<MyEvent>() {
            @Override
            public void onApplicationEvent(MyEvent event) {
                System.out.println("application listener 接收到消息：" + event);
            }
        });
        annotationConfigApplicationContext.refresh();
        annotationConfigApplicationContext.close();
    }
    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
        System.out.println("====");
        applicationEventPublisher.publishEvent(new MyEvent("hello world") {
        });
        applicationEventPublisher.publishEvent("pay load event");
    }
}
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package org.idea.spring.framework.event;
import org.springframework.context.ApplicationEvent;
/**
 * @Author linhao
 * @Date created in 6:21 下午 2021/5/23
 */
public class MyEvent extends ApplicationEvent {
    /**
     * Create a new {@code ApplicationEvent}.
     *
     * @param source the object on which the event initially occurred or with
     *               which the event is associated (never {@code null})
     */
    public MyEvent(Object source) {
        super(source);
    }
}
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package org.idea.spring.framework.event;
import java.util.EventListener;
import java.util.EventObject;
import java.util.Observable;
import java.util.Observer;
/**
 * @Author linhao
 * @Date created in 3:52 下午 2021/5/23
 */
public class EventDemo {
    public static void main(String[] arg) {
        EventObservable observable = new EventObservable();
        observable.addObserver(new EventObserver());
        observable.notifyObservers("send message");
    }
    static class EventObservable extends  Observable {
        @Override
        protected synchronized void setChanged() {
            super.setChanged();
        }
        @Override
        public void notifyObservers(Object data){
            this.setChanged();
            super.notifyObservers(new EventObject(data));
            clearChanged();
        }
    }
    static class EventObserver implements Observer, EventListener {
        @Override
        public void update(Observable o, Object msg) {
            EventObject eventObject = (EventObject) msg;
            System.out.println("接收数据：" + eventObject);
        }
    }
}
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package org.idea.spring.resource;
import org.springframework.core.io.*;
/**
 * @Author linhao
 * @Date created in 7:38 下午 2021/5/23
 */
public class ResourceLoaderDemo {
    public static void main(String[] args) {
        ResourceLoader loader = new DefaultResourceLoader();
        Resource resource = loader.getResource("http://www.baidu.com");
        System.out.println(resource instanceof UrlResource);
        Resource textResource = loader.getResource("classpath:test.txt");
        System.out.println(textResource instanceof ClassPathResource);
    }
}
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public class MyResource implements ApplicationContextAware {
        private ApplicationContext applicationContext;
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
    public void resource() throws IOException {
        Resource resource = applicationContext.getResource("file:D:\\test.txt");
        System.out.println(resource.getFilename());
        System.out.println(resource.contentLength());
    }
}
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