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MemcacheSyncCacheServlet.java
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/
MemcacheSyncCacheServlet.java
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/*
* Copyright 2016 Google Inc.
*
* 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.example.appengine.memcache;
import com.google.appengine.api.memcache.ErrorHandlers;
import com.google.appengine.api.memcache.MemcacheService;
import com.google.appengine.api.memcache.MemcacheServiceFactory;
import java.io.IOException;
import java.math.BigInteger;
import java.util.logging.Level;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
// [START example]
@SuppressWarnings("serial")
// With @WebServlet annotation the webapp/WEB-INF/web.xml is no longer required.
@WebServlet(name = "MemcacheSync", description = "Memcache: Synchronous",
urlPatterns = "/memcache/sync")
public class MemcacheSyncCacheServlet extends HttpServlet {
@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException,
ServletException {
String path = req.getRequestURI();
if (path.startsWith("/favicon.ico")) {
return; // ignore the request for favicon.ico
}
MemcacheService syncCache = MemcacheServiceFactory.getMemcacheService();
syncCache.setErrorHandler(ErrorHandlers.getConsistentLogAndContinue(Level.INFO));
String key = "count-sync";
byte[] value;
long count = 1;
value = (byte[]) syncCache.get(key);
if (value == null) {
value = BigInteger.valueOf(count).toByteArray();
syncCache.put(key, value);
} else {
// Increment value
count = new BigInteger(value).longValue();
count++;
value = BigInteger.valueOf(count).toByteArray();
// Put back in cache
syncCache.put(key, value);
}
// Output content
resp.setContentType("text/plain");
resp.getWriter().print("Value is " + count + "\n");
}
}
// [END example]