/* | |
* Copyright 1999-2011 Alibaba Group. | |
* | |
* 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 com.alibaba.dubbo.container.page; | |
import java.io.ByteArrayOutputStream; | |
import java.io.File; | |
import java.io.FileInputStream; | |
import java.io.IOException; | |
import java.io.InputStream; | |
import java.io.OutputStream; | |
import java.net.URL; | |
import java.util.ArrayList; | |
import java.util.List; | |
import javax.servlet.Filter; | |
import javax.servlet.FilterChain; | |
import javax.servlet.FilterConfig; | |
import javax.servlet.ServletException; | |
import javax.servlet.ServletRequest; | |
import javax.servlet.ServletResponse; | |
import javax.servlet.http.HttpServletRequest; | |
import javax.servlet.http.HttpServletResponse; | |
import com.alibaba.dubbo.common.Constants; | |
/** | |
* ResourceServlet | |
* | |
* @author william.liangf | |
*/ | |
public class ResourceFilter implements Filter { | |
private static final String CLASSPATH_PREFIX = "classpath:"; | |
private final long start = System.currentTimeMillis(); | |
private final List<String> resources = new ArrayList<String>(); | |
public void init(FilterConfig filterConfig) throws ServletException { | |
String config = filterConfig.getInitParameter("resources"); | |
if (config != null && config.length() > 0) { | |
String[] configs = Constants.COMMA_SPLIT_PATTERN.split(config); | |
for (String c : configs) { | |
if (c != null && c.length() > 0) { | |
c = c.replace('\\', '/'); | |
if (c.endsWith("/")) { | |
c = c.substring(0, c.length() - 1); | |
} | |
resources.add(c); | |
} | |
} | |
} | |
} | |
public void destroy() { | |
} | |
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) | |
throws IOException, ServletException { | |
HttpServletRequest request = (HttpServletRequest) req; | |
HttpServletResponse response = (HttpServletResponse) res; | |
if (response.isCommitted()) { | |
return; | |
} | |
String uri = request.getRequestURI(); | |
String context = request.getContextPath(); | |
if (uri.endsWith("/favicon.ico")) { | |
uri = "/favicon.ico"; | |
} else if (context != null && ! "/".equals(context)) { | |
uri = uri.substring(context.length()); | |
} | |
if (! uri.startsWith("/")) { | |
uri = "/" + uri; | |
} | |
long lastModified = getLastModified(uri); | |
long since = request.getDateHeader("If-Modified-Since"); | |
if (since >= lastModified) { | |
response.sendError(HttpServletResponse.SC_NOT_MODIFIED); | |
return; | |
} | |
byte[] data; | |
InputStream input = getInputStream(uri); | |
if (input == null) { | |
chain.doFilter(req, res); | |
return; | |
} | |
try { | |
ByteArrayOutputStream output = new ByteArrayOutputStream(); | |
byte[] buffer = new byte[8192]; | |
int n = 0; | |
while (-1 != (n = input.read(buffer))) { | |
output.write(buffer, 0, n); | |
} | |
data = output.toByteArray(); | |
} finally { | |
input.close(); | |
} | |
response.setDateHeader("Last-Modified", lastModified); | |
OutputStream output = response.getOutputStream(); | |
output.write(data); | |
output.flush(); | |
} | |
private boolean isFile(String path) { | |
return path.startsWith("/") || path.indexOf(":") <= 1; | |
} | |
private long getLastModified(String uri) { | |
for (String resource : resources) { | |
if (resource != null && resource.length() > 0) { | |
String path = resource + uri; | |
if (isFile(path)) { | |
File file = new File(path); | |
if (file.exists()) { | |
return file.lastModified(); | |
} | |
} | |
} | |
} | |
return start; | |
} | |
private InputStream getInputStream(String uri) { | |
for (String resource : resources) { | |
String path = resource + uri; | |
try { | |
if (isFile(path)) { | |
return new FileInputStream(path); | |
} else if (path.startsWith(CLASSPATH_PREFIX)) { | |
return Thread.currentThread().getContextClassLoader().getResourceAsStream(path.substring(CLASSPATH_PREFIX.length())); | |
} else { | |
return new URL(path).openStream(); | |
} | |
} catch (IOException e) { | |
} | |
} | |
return null; | |
} | |
} |