package org.apache.helix.webapp.resources;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 java.util.List;
import org.apache.helix.ZNRecord;
import org.apache.helix.manager.zk.ZkClient;
import org.apache.helix.webapp.RestAdminApplication;
import org.apache.log4j.Logger;
import org.apache.zookeeper.data.Stat;
import org.restlet.Context;
import org.restlet.data.MediaType;
import org.restlet.data.Request;
import org.restlet.data.Response;
import org.restlet.data.Status;
import org.restlet.resource.Representation;
import org.restlet.resource.Resource;
import org.restlet.resource.StringRepresentation;
import org.restlet.resource.Variant;
public class ZkChildResource extends Resource
{
private final static Logger LOG = Logger.getLogger(ZkChildResource.class);
public ZkChildResource(Context context, Request request, Response response)
{
super(context, request, response);
getVariants().add(new Variant(MediaType.TEXT_PLAIN));
getVariants().add(new Variant(MediaType.APPLICATION_JSON));
}
@Override
public boolean allowGet()
{
return true;
}
@Override
public boolean allowPost()
{
return false;
}
@Override
public boolean allowPut()
{
return false;
}
@Override
public boolean allowDelete()
{
return true;
}
private String getZKPath()
{
String relativeRef = getRequest().getResourceRef().getRelativeRef().toString();
if (relativeRef.equals("."))
{
relativeRef = "";
}
// strip off trailing "/"
while (relativeRef.endsWith("/"))
{
relativeRef = relativeRef.substring(0, relativeRef.length() - 1);
}
return "/" + relativeRef;
}
@Override
public Representation represent(Variant variant)
{
StringRepresentation presentation = null;
String zkPath = getZKPath();
try
{
ZkClient zkClient =
(ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
ZNRecord result = readZkChild(zkPath, zkClient);
presentation =
new StringRepresentation(ClusterRepresentationUtil.ZNRecordToJson(result),
MediaType.APPLICATION_JSON);
}
catch (Exception e)
{
String error = ClusterRepresentationUtil.getErrorAsJsonStringFromException(e);
presentation = new StringRepresentation(error, MediaType.APPLICATION_JSON);
LOG.error("Error in read zkPath: " + zkPath, e);
}
return presentation;
}
private ZNRecord readZkChild(String zkPath, ZkClient zkClient)
{
ZNRecord result = null;
// read data and stat
Stat stat = new Stat();
ZNRecord data = zkClient.readDataAndStat(zkPath, stat, true);
if (data != null)
{
result = data;
}
else
{
result = new ZNRecord("");
}
// read childrenList
List<String> children = zkClient.getChildren(zkPath);
if (children != null && children.size() > 0)
{
result.setSimpleField("numChildren", "" + children.size());
result.setListField("childrenList", children);
} else
{
result.setSimpleField("numChildren", "" + 0);
}
return result;
}
@Override
public void removeRepresentations()
{
String zkPath = getZKPath();
try
{
ZkClient zkClient =
(ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
List<String> childNames = zkClient.getChildren(zkPath);
if (childNames != null)
{
for (String childName : childNames)
{
String childPath = zkPath.equals("/")? "/" + childName : zkPath + "/" + childName;
zkClient.deleteRecursive(childPath);
}
}
getResponse().setStatus(Status.SUCCESS_OK);
}
catch (Exception e)
{
getResponse().setEntity(ClusterRepresentationUtil.getErrorAsJsonStringFromException(e),
MediaType.APPLICATION_JSON);
getResponse().setStatus(Status.SUCCESS_OK);
LOG.error("Error in delete zkChild: " + zkPath, e);
}
}
}