/**
* Copyright (c) 2005-2012 https://github.com/zhangkaitao
*
* Licensed under the Apache License, Version 2.0 (the "License");
*/
package com.sishuok.bigpipe.handler;
import com.sishuok.bigpipe.*;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.core.MethodParameter;
import org.springframework.util.Assert;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.async.DeferredResult;
import org.springframework.web.context.request.async.WebAsyncUtils;
import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
import org.springframework.web.method.support.ModelAndViewContainer;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
/**
* <p>User: Zhang Kaitao
* <p>Date: 13-7-29 下午12:06
* <p>Version: 1.0
*/
public class BigpipeTaskReturnValueHandler implements
HandlerMethodReturnValueHandler, ApplicationContextAware, InitializingBean {
private ApplicationContext applicationContext;
private PageletFinder pageletFinder;
private PageletViewResolver pageletViewResolver;
private Executor executor;
public void setExecutor(final Executor executor) {
this.executor = executor;
}
public void setPageletFinder(final PageletFinder pageletFinder) {
this.pageletFinder = pageletFinder;
}
public void setPageletResolver(final PageletViewResolver pageletViewResolver) {
this.pageletViewResolver = pageletViewResolver;
}
@Override
public void setApplicationContext(final ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
@Override
public void afterPropertiesSet() throws Exception {
if(executor == null) {
executor = Executors.newScheduledThreadPool(10);
}
if(pageletFinder == null) {
pageletFinder = applicationContext.getBean(PageletFinder.class);
}
if(pageletViewResolver == null) {
pageletViewResolver = applicationContext.getBean(PageletViewResolver.class);
}
Assert.notNull(pageletFinder, "must define a PageletFinder");
Assert.notNull(pageletViewResolver, "must define a PageletViewResolver");
}
@Override
public boolean supportsReturnType(final MethodParameter returnType) {
return BigPipeTask.class.isAssignableFrom(returnType.getParameterType());
}
@Override
public void handleReturnValue(final Object returnValue, final MethodParameter returnType, final ModelAndViewContainer mavContainer, final NativeWebRequest webRequest) throws Exception {
final BigPipeTask bigPipeTask = (BigPipeTask) returnValue;
final HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
final HttpServletResponse response = webRequest.getNativeResponse(HttpServletResponse.class);
final DeferredResult<Void> deferredResult = new DeferredResult<Void>();
mavContainer.setRequestHandled(true);
WebAsyncUtils.getAsyncManager(request).startDeferredResultProcessing(deferredResult, mavContainer);
final BigPipeContext context = new BigPipeContext(request.getContextPath(), bigPipeTask.getModel());
//获取第一个pagelet（即框架部分） 第一个部分暂时不用异步
final String framePageletName = bigPipeTask.getFramePageletName();
final Pagelet framePagelet = pageletFinder.find(framePageletName);
Assert.notNull(framePagelet, framePageletName + " pagelet not exists");
final BigPipeContext frameContext = context.copy();
final PageletResult framePageletResult = framePagelet.run(frameContext, response);
final PageletView framePageletView = pageletViewResolver.resolve(framePageletResult);
framePageletView.render(frameContext, response);
final AtomicInteger counter = new AtomicInteger(bigPipeTask.getPageletNames().size());
//接下来的N个pagelet使用异步任务完成
for(String otherPageletName : bigPipeTask.getPageletNames()) {
final Pagelet pagelet = pageletFinder.find(otherPageletName);
Assert.notNull(pagelet, otherPageletName + " pagelet not exists");
//然后提交队列执行
executor.execute(new Runnable() {
@Override
public void run() {
try {
final BigPipeContext pageletContext = context.copy();
final PageletResult pageletResult = pagelet.run(pageletContext, response);
final PageletView pageletView = pageletViewResolver.resolve(pageletResult);
pageletView.render(pageletContext, response);
} catch (Exception e) {
e.printStackTrace();
//暂时忽略
}
if (counter.decrementAndGet() <= 0) {
deferredResult.setResult(null);
}
}
});
}
}
}