工廠模式

只對結(jié)果負責(zé)，封裝創(chuàng)建過程，如BeanFactory

    Object getBean(String name) throws BeansException;

單例模式

保證獨一無二面徽，如ApplicationContext

原型模式

拔一根猴毛腻要，吹出千萬個复罐，如BeanUtils

    public static void copyProperties(Object source, Object target) throws BeansException {
        copyProperties(source, target, null, (String[]) null);
    }

代理模式

招人辦事，增強職責(zé)雄家，如JdkDynamicAopProxy

final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializable {

    @Override
    public Object getProxy(@Nullable ClassLoader classLoader) {
        if (logger.isDebugEnabled()) {
            logger.debug("Creating JDK dynamic proxy: target source is " + this.advised.getTargetSource());
        }
        Class<?>[] proxiedInterfaces = AopProxyUtils.completeProxiedInterfaces(this.advised, true);
        findDefinedEqualsAndHashCodeMethods(proxiedInterfaces);
        return Proxy.newProxyInstance(classLoader, proxiedInterfaces, this);
    }

    @Override
    @Nullable
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        MethodInvocation invocation;
        Object oldProxy = null;
        boolean setProxyContext = false;

        TargetSource targetSource = this.advised.targetSource;

還有CglibAopProxy

class CglibAopProxy implements AopProxy, Serializable {

      //...

    private static class StaticUnadvisedInterceptor implements MethodInterceptor, Serializable {
        @Override
        @Nullable
        public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
            Object retVal = methodProxy.invoke(this.target, args);
            return processReturnType(proxy, this.target, method, retVal);
        }
      //...

     private static class EqualsInterceptor implements MethodInterceptor, Serializable {
        @Override
        public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) {
            Object other = args[0];
            if (proxy == other) {
                return true;
            }
            if (other instanceof Factory) {
                Callback callback = ((Factory) other).getCallback(INVOKE_EQUALS);
                if (!(callback instanceof EqualsInterceptor)) {
                    return false;
                }
                AdvisedSupport otherAdvised = ((EqualsInterceptor) callback).advised;
                return AopProxyUtils.equalsInProxy(this.advised, otherAdvised);
            }
            else {
                return false;
            }
        }

    //...

委派模式

干活算你的（普通員工）效诅，功勞算我的（項目經(jīng)理），如DispatcherServlet

@Nullable
    protected HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
        if (this.handlerMappings != null) {
            for (HandlerMapping hm : this.handlerMappings) {
                if (logger.isTraceEnabled()) {
                    logger.trace(
                            "Testing handler map [" + hm + "] in DispatcherServlet with name '" + getServletName() + "'");
                }
                HandlerExecutionChain handler = hm.getHandler(request);
                if (handler != null) {
                    return handler;
                }
            }
        }
        return null;
    }

還有BeanDefinitionParserDelegate

模板模式

在Spring的AbstractApplicationContext.java中趟济，refresh()是典型的模板模式乱投，代碼如下

@Override
    public void refresh() throws BeansException, IllegalStateException {
        synchronized (this.startupShutdownMonitor) {
            // Prepare this context for refreshing.
            //1.調(diào)用容器準(zhǔn)備刷新的方法，獲取容器的當(dāng)時時間顷编，同時給容器設(shè)置同步標(biāo)志
            prepareRefresh();

            // Tell the subclass to refresh the internal bean factory.
            //2.告訴子類啟動refreshBeanFactory()方法戚炫，Bean定義資源文件的載入，從子類的refreshBeanFactory()方法啟動
            ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

            // Prepare the bean factory for use in this context.
            //3.為BeanFactory配置容器特性媳纬，例如類加載器双肤、事件處理等
            prepareBeanFactory(beanFactory);

            try {
                // Allows post-processing of the bean factory in context subclasses.
                postProcessBeanFactory(beanFactory);

                // Invoke factory processors registered as beans in the context.
                invokeBeanFactoryPostProcessors(beanFactory);

                // Register bean processors that intercept bean creation.
                registerBeanPostProcessors(beanFactory);

    

還有JdbcTemplate施掏、HttpServlet

適配器模式

兼容轉(zhuǎn)換頭，如AdvisorAdapter茅糜、HandlerAdapter

    boolean supportsAdvice(Advice advice);
    MethodInterceptor getInterceptor(Advisor advisor);

裝飾器模式

包裝七芭，同宗同源，如BufferdReader限匣、InputStream抖苦、OutputStream、HttpHeadResponseDecorator

public class BufferedReader extends Reader {

//...
    public BufferedReader(Reader in, int sz) {
        super(in);
        if (sz <= 0)
            throw new IllegalArgumentException("Buffer size <= 0");
        this.in = in;
        cb = new char[sz];
        nextChar = nChars = 0;
    }

觀察者模式

任務(wù)完成時通知米死，如ContextLoaderListener