/* | |
* | |
* 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. | |
* | |
*/ | |
package org.apache.qpid.management.web.action; | |
import java.io.IOException; | |
import java.lang.management.ManagementFactory; | |
import java.util.HashMap; | |
import java.util.Hashtable; | |
import java.util.Map; | |
import java.util.Properties; | |
import java.util.Map.Entry; | |
import javax.management.MBeanAttributeInfo; | |
import javax.management.MBeanInfo; | |
import javax.management.MBeanServer; | |
import javax.management.MalformedObjectNameException; | |
import javax.management.ObjectName; | |
import javax.servlet.RequestDispatcher; | |
import javax.servlet.ServletException; | |
import javax.servlet.http.HttpServlet; | |
import javax.servlet.http.HttpServletRequest; | |
import javax.servlet.http.HttpServletResponse; | |
/** | |
* This controller is responsible to provide a jmx perspective of a specific resource. | |
* That means that this controller is querying the Platform MBean server in order to | |
* get metadata for the requested mbean. | |
* | |
* After that metadata will be forwarded to the appropriate view page and therefore | |
* will be shown on the Admin console. | |
* | |
* @author Andrea Gazzarini | |
*/ | |
public class JmxPerspectiveAction extends HttpServlet | |
{ | |
private static final long serialVersionUID = -2411413147821629363L; | |
/** | |
* Adapter interface for converting objects on html strings. | |
* | |
* @author Andrea Gazzarini. | |
*/ | |
interface JavaToHtmlAdapter | |
{ | |
/** | |
* Returns an HTML string representation of the given object. | |
* | |
* @param javaObject the object that needs to be converted. | |
* @return an html string containing value of the given object. | |
*/ | |
String toHtml(Object javaObject); | |
} | |
/** | |
* Adapter implementation for Map (and subclasses). | |
*/ | |
private JavaToHtmlAdapter mapAdapter = new JavaToHtmlAdapter() | |
{ | |
@SuppressWarnings("unchecked") | |
public String toHtml(Object javaObject) | |
{ | |
Map<String,Object> value = (Map<String, Object>) javaObject; | |
// Sanity check : if the map is empty or null there's no need to | |
// do any convertion | |
if (value == null || value.isEmpty()) | |
{ | |
return "(empty)"; | |
} | |
StringBuilder builder = new StringBuilder("<ul>"); | |
for (Entry<String, Object> entry : value.entrySet()) | |
{ | |
builder | |
.append("<li>") | |
.append(entry.getKey()) | |
.append(" = ") | |
.append(entry.getValue()); | |
} | |
builder.append("</ul>"); | |
return builder.toString(); | |
} | |
}; | |
private Map<String, JavaToHtmlAdapter> _adapters = new HashMap<String, JavaToHtmlAdapter>(); | |
@Override | |
public void init() throws ServletException | |
{ | |
_adapters.put(Map.class.getName(), mapAdapter); | |
_adapters.put(HashMap.class.getName(),mapAdapter); | |
_adapters.put(Properties.class.getName(),mapAdapter); | |
_adapters.put(Hashtable.class.getName(),mapAdapter); | |
} | |
@SuppressWarnings("unchecked") | |
@Override | |
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException | |
{ | |
String resourceId = null; | |
try | |
{ | |
resourceId = request.getParameter("resourceId"); | |
ObjectName objectName = new ObjectName(resourceId); | |
String [] keyProperties = objectName.getKeyPropertyListString().split(","); | |
MBeanServer server = ManagementFactory.getPlatformMBeanServer(); | |
MBeanInfo metadata = server.getMBeanInfo(objectName); | |
Map<String, String> attributes = getAttributes(server, objectName,metadata.getAttributes()); | |
request.setAttribute("resourceId", objectName); | |
request.setAttribute("metadata",metadata); | |
request.setAttribute("nameAttributes",keyProperties); | |
request.setAttribute("attributes",attributes); | |
RequestDispatcher dispatcher = request.getRequestDispatcher("/jmx_perspective.jsp"); | |
dispatcher.forward(request,response); | |
} catch(MalformedObjectNameException exception) | |
{ | |
request.setAttribute("errorMessage","Malformed Resource ID : supplied value is "+resourceId); | |
request.setAttribute("exception",exception); | |
RequestDispatcher dispatcher = request.getRequestDispatcher("/error_page.jsp"); | |
dispatcher.forward(request,response); | |
} | |
catch(Exception exception) | |
{ | |
request.setAttribute("errorMessage","Unable to detect the exact cause Please look at the reported stack trace below."); | |
request.setAttribute("exception",exception); | |
RequestDispatcher dispatcher = request.getRequestDispatcher("/error_page.jsp"); | |
dispatcher.forward(request,response); | |
} | |
} | |
/** | |
* Starting from an mbean metadata, this method retrieves all the attributes | |
* from the corresponding MBean Server. | |
* | |
* @param server the mbean server where the target mbean is registered. | |
* @param name the name of the target mbean. | |
* @param metadata the metadata of mbean. | |
* @return a map containing all attributes of the given mbean. | |
* @throws Exception when it's not possible to retrieve attributes. | |
*/ | |
private Map<String, String> getAttributes(MBeanServer server, ObjectName name, MBeanAttributeInfo [] metadata) throws Exception | |
{ | |
Map<String,String> result = new HashMap<String, String>(metadata.length); | |
for (MBeanAttributeInfo attribute : metadata) | |
{ | |
Object value = server.getAttribute(name, attribute.getName()); | |
result.put(attribute.getName(),getAdaptedValue(attribute.getType(), value)); | |
} | |
return result; | |
} | |
/** | |
* Converts the given attribute value in a html string format. | |
* | |
* @param type the java type of the given attribute value. | |
* @param value the attribute value. | |
* @return a html string format of the given value. | |
*/ | |
private String getAdaptedValue(String type, Object value) | |
{ | |
JavaToHtmlAdapter adapter = _adapters.get(type); | |
return (adapter != null) ? adapter.toHtml(value) : String.valueOf(value); | |
} | |
} |