/*
* Copyright 2008-2009 the original 赵永春(zyc@hasor.net).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.hasor.plugins.resource;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLDecoder;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.hasor.core.AppContext;
import net.hasor.core.Hasor;
import net.hasor.web.startup.RuntimeListener;
import org.more.util.ContextClassLoaderLocal;
import org.more.util.FileUtils;
import org.more.util.IOUtils;
import org.more.util.StringUtils;
/**
* 负责装载jar包或zip包中的资源
* @version : 2013-6-5
* @author 赵永春 (zyc@hasor.net)
*/
public class ResourceHttpServlet extends HttpServlet {
private static final long serialVersionUID = 2470188139577613256L;
private static ContextClassLoaderLocal<ResourceLoader[]> LoaderList = new ContextClassLoaderLocal<ResourceLoader[]>();
private static ContextClassLoaderLocal<File> CacheDir = new ContextClassLoaderLocal<File>();
private Map<String, ReadWriteLock> cachingRes = new HashMap<String, ReadWriteLock>();
private boolean isDebug;
//
public synchronized void init(ServletConfig config) throws ServletException {
AppContext appContext = RuntimeListener.getLocalAppContext();
this.isDebug = appContext.getEnvironment().isDebug();
//
ResourceLoader[] resLoaderArray = LoaderList.get();
if (resLoaderArray != null)
return;
ResourceLoaderFactory factory = appContext.getInstance(ResourceLoaderFactory.class);
resLoaderArray = factory.loaderArray(appContext);
if (resLoaderArray != null && resLoaderArray.length != 0)
LoaderList.set(resLoaderArray);
}
public synchronized static void initCacheDir(File cacheDir) {
FileUtils.deleteDir(cacheDir);
cacheDir.mkdirs();
CacheDir.set(cacheDir);
Hasor.logInfo("use cacheDir %s", cacheDir);
}
//
//
//
//
/**响应资源*/
private void forwardTo(File file, ServletRequest request, ServletResponse response) throws IOException, ServletException {
if (response.isCommitted() == true)
return;
HttpServletRequest req = (HttpServletRequest) request;
String requestURI = req.getRequestURI();
String fileExt = requestURI.substring(requestURI.lastIndexOf("."));
String typeMimeType = req.getSession(true).getServletContext().getMimeType(fileExt);
if (StringUtils.isBlank(typeMimeType))
Hasor.logError("%s not mapping MimeType!", requestURI); //typeMimeType = this.getMimeType().get(fileExt.substring(1).toLowerCase());
//
if (typeMimeType != null)
response.setContentType(typeMimeType);
FileInputStream cacheFile = new FileInputStream(file);
IOUtils.copy(cacheFile, response.getOutputStream());
cacheFile.close();
}
//
//
/*获取 ReadWriteLock 锁*/
private synchronized ReadWriteLock getReadWriteLock(String requestURI) {
ReadWriteLock cacheRWLock = null;
if (this.cachingRes.containsKey(requestURI) == true) {
cacheRWLock = this.cachingRes.get(requestURI);
} else {
cacheRWLock = new ReentrantReadWriteLock();
this.cachingRes.put(requestURI, cacheRWLock);
}
return cacheRWLock;
}
/*释放 ReadWriteLock 锁*/
private synchronized void releaseReadWriteLock(String requestURI) {
if (this.cachingRes.containsKey(requestURI) == true)
this.cachingRes.remove(requestURI);
}
/**资源服务入口方法*/
public void service(ServletRequest request, ServletResponse response) throws IOException, ServletException {
//1.确定时候拦截
HttpServletRequest req = (HttpServletRequest) request;
String requestURI = req.getRequestURI();
try {
requestURI = URLDecoder.decode(requestURI, "utf-8");
} catch (Exception e) {}
//2.检查缓存路径中是否存在
File cacheFile = new File(CacheDir.get(), requestURI);
if (this.isDebug) {
boolean mark = this.cacheRes(cacheFile, requestURI, request, response);
if (mark)
this.forwardTo(cacheFile, request, response);
else
((HttpServletResponse) response).sendError(404, "not exist :" + requestURI);
return;
}
//3.创建锁-A
ReadWriteLock cacheRWLock = this.getReadWriteLock(requestURI);
//4.在锁下缓存文件，下面代码是为了防止缓存穿透
boolean forwardType = true;
cacheRWLock.readLock().lock();//读取锁定
if (!cacheFile.exists()) {
/*升级锁*/
cacheRWLock.readLock().unlock();
cacheRWLock.writeLock().lock();
/*在debug模式下，或者尚未缓存时*/
if (this.isDebug || !cacheFile.exists()) {
forwardType = this.cacheRes(cacheFile, requestURI, request, response);//当缓存失败时返回false
}
cacheRWLock.readLock().lock();
cacheRWLock.writeLock().unlock();
}
cacheRWLock.readLock().unlock();//读取解锁
//5.缓存完毕
if (forwardType)
this.forwardTo(cacheFile, request, response);
else
((HttpServletResponse) response).sendError(404, "not exist this resource ‘" + requestURI + "’");
//6.释放锁-A
this.releaseReadWriteLock(requestURI);
}
/*资源缓存*/
private boolean cacheRes(File cacheFile, String requestURI, ServletRequest request, ServletResponse response) throws IOException, ServletException {
//3.尝试载入资源
ResourceLoader inLoader = null;
InputStream inStream = null;
ResourceLoader[] loaderList = LoaderList.get();
if (loaderList == null || loaderList.length == 0)
return false;
//
for (ResourceLoader loader : loaderList) {
if (loader.exist(requestURI) == false)
continue;
if (this.isDebug) {
if (!loader.canModify(requestURI) && cacheFile.exists())
return true;
}
//
inLoader = loader;
inStream = loader.getResourceAsStream(requestURI);
if (inStream != null)
break;
}
if (inStream == null)
return false;
//4.写入临时文件夹
cacheFile.getParentFile().mkdirs();
FileOutputStream out = new FileOutputStream(cacheFile);
IOUtils.copy(inStream, out);
inLoader.close(inStream);
out.flush();
out.close();
return true;
}
}