org.apache.hadoop.jmx

类 JMXJsonServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.apache.hadoop.jmx.JMXJsonServlet

所有已实现的接口:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class JMXJsonServlet
extends javax.servlet.http.HttpServlet

Provides Read only web access to JMX.

This servlet generally will be placed under the /jmx URL for each HttpServer. It provides read only access to JMX metrics. The optional qry parameter may be used to query only a subset of the JMX Beans. This query functionality is provided through the MBeanServer.queryNames(ObjectName, javax.management.QueryExp) method.

For example http://.../jmx?qry=Hadoop:* will return all hadoop metrics exposed through JMX.

If the qry parameter is not formatted correctly then a 400 BAD REQUEST http response code will be returned.

The return format is JSON and in the form

  {
    "beans" : [
      {
        "name":"bean-name"
        ...
      }
    ]
  }
  

The servlet attempts to convert the the JMXBeans into JSON. Each bean's attributes will be converted to a JSON object member. If the attribute is a boolean, a number, a string, or an array it will be converted to the JSON equivalent. If the value is a CompositeData then it will be converted to a JSON object with the keys as the name of the JSON member and the value is converted following these same rules. If the value is a TabularData then it will be converted to an array of the CompositeData elements that it contains. All other objects will be converted to a string and output as such. The bean's name and modelerType will be returned for all beans.

另请参阅:

序列化表格

字段概要

字段

限定符和类型	字段和说明
protected MBeanServer	mBeanServer MBean server.

构造器概要

构造器

构造器和说明
JMXJsonServlet()

方法概要

方法

限定符和类型	方法和说明
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Process a GET request for the specified resource.
void	init() Initialize this servlet.

从类继承的方法 javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service

从类继承的方法 javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

mBeanServer

protected transient MBeanServer mBeanServer

MBean server.

构造器详细资料

JMXJsonServlet

public JMXJsonServlet()

方法详细资料

init

public void init()
          throws javax.servlet.ServletException

Initialize this servlet.

覆盖:

init 在类中 javax.servlet.GenericServlet

抛出:

javax.servlet.ServletException

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
         javax.servlet.http.HttpServletResponse response)

Process a GET request for the specified resource.

覆盖:

doGet 在类中 javax.servlet.http.HttpServlet

参数:

request - The servlet request we are processing

response - The servlet response we are creating