org.apache.ojb.broker.locking.LockManagerServlet Maven / Gradle / Ivy
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package org.apache.ojb.broker.locking;
/* Copyright 2004-2005 The Apache Software Foundation
*
* 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.
*/
import javax.servlet.ServletException;
import javax.servlet.ServletConfig;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import org.apache.commons.lang.math.NumberUtils;
import org.apache.ojb.broker.util.ClassHelper;
/**
* @author Thomas Mahler
*/
public class LockManagerServlet extends HttpServlet
{
protected static LockManager lockmanager;
static final String STR_LOCK_TIMEOUT = "lockTimeout";
static final String STR_BLOCK_TIMEOUT = "blockTimeout";
static final String STR_LOCK_MANAGER = "lockManager";
private static long numRequests;
private static Throwable lastError = null;
public void init(ServletConfig servletConfig) throws ServletException
{
super.init(servletConfig);
// if lock manager was instantiated not yet
if(lockmanager == null)
{
lastError = null;
numRequests = 0;
String strLockManager = servletConfig.getInitParameter(STR_LOCK_MANAGER);
try
{
lockmanager = (LockManager) (strLockManager != null ?
ClassHelper.newInstance(strLockManager) : ClassHelper.newInstance(LockManagerInMemoryImpl.class));
}
catch(Exception e)
{
lastError = new LockRuntimeException("Can't instance lock manager, init parameter 'lockManager': " + strLockManager);
e.printStackTrace();
}
String strTimeout = servletConfig.getInitParameter(STR_LOCK_TIMEOUT);
if(NumberUtils.isNumber(strTimeout))
{
try
{
Long lockTimeout = NumberUtils.createLong(strTimeout);
lockmanager.setLockTimeout(lockTimeout.longValue());
}
catch(Exception e)
{
if(lastError == null)
{
lastError = new LockRuntimeException("Can't convert 'lockTimeout' init parameter: " + strTimeout);
}
e.printStackTrace();
}
}
String strBlock = servletConfig.getInitParameter(STR_BLOCK_TIMEOUT);
if(NumberUtils.isNumber(strBlock))
{
try
{
Long blockTimeout = NumberUtils.createLong(strBlock);
lockmanager.setLockTimeout(blockTimeout.longValue());
}
catch(Exception e)
{
if(lastError == null)
{
lastError = new LockRuntimeException("Can't convert 'blockTimeout' init parameter: " + strBlock);
}
e.printStackTrace();
}
}
}
}
/* (non-Javadoc)
* @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
response.setContentType("text/html");
response.setHeader("Pragma", "no-cache");
PrintWriter out = response.getWriter();
out.println("OJB Distributed Locking Servlet Status Page ");
out.println("OJB Distributed Locking Servlet
");
out.println("The servlet is running.");
if(lastError == null)
{
out.println("The LockServer is running.
");
out.println("LockManager info: " + lockmanager.getLockInfo() + "
");
out.println("Processed Lock Request: " + numRequests + "
");
}
else
{
out.println("
The LockServer has a problem!
");
out.println("The error message is:");
out.println(lastError.getMessage() + "
");
lastError.printStackTrace(out);
lastError = null;
}
out.println("");
}
/* (non-Javadoc)
* @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
// update counter
numRequests++;
try
{
// read request:
LockManagerRemoteImpl.LockInfo info = (LockManagerRemoteImpl.LockInfo) buildObjectFromRequest(request);
Object result = null;
// now execute the command specified by the selector
try
{
switch(info.methodName)
{
case LockManagerRemoteImpl.METHOD_READ_LOCK:
{
result = new Boolean(lockmanager.readLock(info.key, info.resourceId, info.isolationLevel));
break;
}
case LockManagerRemoteImpl.METHOD_RELEASE_SINGLE_LOCK:
{
result = new Boolean(lockmanager.releaseLock(info.key, info.resourceId));
break;
}
case LockManagerRemoteImpl.METHOD_RELEASE_LOCKS:
{
lockmanager.releaseLocks(info.key);
result = Boolean.TRUE;
break;
}
case LockManagerRemoteImpl.METHOD_WRITE_LOCK:
{
result = new Boolean(lockmanager.writeLock(info.key, info.resourceId,
info.isolationLevel));
break;
}
case LockManagerRemoteImpl.METHOD_UPGRADE_LOCK:
{
result = new Boolean(lockmanager.upgradeLock(info.key, info.resourceId, info.isolationLevel));
break;
}
case LockManagerRemoteImpl.METHOD_CHECK_READ:
{
result = new Boolean(lockmanager.hasRead(info.key, info.resourceId));
break;
}
case LockManagerRemoteImpl.METHOD_CHECK_WRITE:
{
result = new Boolean(lockmanager.hasWrite(info.key, info.resourceId));
break;
}
case LockManagerRemoteImpl.METHOD_CHECK_UPGRADE:
{
result = new Boolean(lockmanager.hasUpgrade(info.key, info.resourceId));
break;
}
case LockManagerRemoteImpl.METHOD_LOCK_INFO:
{
result = lockmanager.getLockInfo();
break;
}
case LockManagerRemoteImpl.METHOD_LOCK_TIMEOUT:
{
result = new Long(lockmanager.getLockTimeout());
break;
}
case LockManagerRemoteImpl.METHOD_BLOCK_TIMEOUT:
{
result = new Long(lockmanager.getBlockTimeout());
break;
}
// case LockManagerRemoteImpl.METHOD_LOCK_TIMEOUT_SET:
// {
// lockmanager.setLockTimeout(info.lockTimeout);
// break;
// }
//
// case LockManagerRemoteImpl.METHOD_BLOCK_TIMEOUT_SET:
// {
// lockmanager.setBlockTimeout(info.blockTimeout);
// break;
// }
default :
{
throw new LockRuntimeException("Unknown command:" + info.methodName);
}
}
}
catch(RuntimeException e)
{
result = new LockRuntimeException("Error while invoke specified method in servlet.", e);
}
ObjectOutputStream oos = new ObjectOutputStream(response.getOutputStream());
oos.writeObject(result);
oos.flush();
oos.close();
}
catch(Throwable t)
{
lastError = t;
t.printStackTrace();
}
}
private Object buildObjectFromRequest(HttpServletRequest request) throws IOException, ClassNotFoundException
{
Object obj = null;
// get the body of the request as binary data
InputStream is = request.getInputStream();
ObjectInputStream objInputStream = new ObjectInputStream(is);
obj = objInputStream.readObject();
objInputStream.close();
is.close();
return obj;
}
}