Package org.apache.catalina.manager

Class JMXProxyServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.apache.catalina.manager.JMXProxyServlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

public class JMXProxyServlet
extends HttpServlet

This servlet will dump JMX attributes in a simple format and implement proxy services for modeler.

Author:

Costin Manolache

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected MBeanServer	mBeanServer	MBean server.
protected Registry	registry

Constructor Summary

Constructors

Constructor	Description
JMXProxyServlet()

Method Summary

Modifier and Type	Method	Description
void	doGet(HttpServletRequest request, HttpServletResponse response)	Called by the server (via the service method) to allow a servlet to handle a GET request.
void	getAttribute(PrintWriter writer, String onameStr, String att, String key)
void	init()	A convenience method which can be overridden so that there's no need to call super.init(config).
boolean	isSupported(String type)	Determines if a type is supported by the JMXProxyServlet.
void	listBeans(PrintWriter writer, String qry)
void	setAttribute(PrintWriter writer, String onameStr, String att, String val)

Methods inherited from class javax.servlet.http.HttpServlet

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

Methods inherited from class javax.servlet.GenericServlet

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

Methods inherited from class java.lang.Object

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

Field Details

mBeanServer

protected transient MBeanServer mBeanServer

MBean server.

registry

protected transient Registry registry

Constructor Details

JMXProxyServlet

public JMXProxyServlet()

Method Details

init

public void init()
          throws ServletException

Description copied from class: javax.servlet.GenericServlet

A convenience method which can be overridden so that there's no need to call super.init(config).

Instead of overriding GenericServlet.init(ServletConfig), simply override this method and it will be called by GenericServlet.init(ServletConfig config). The ServletConfig object can still be retrieved via GenericServlet.getServletConfig().

Overrides:

init in class GenericServlet

Throws:

ServletException - if an exception occurs that interrupts the servlet's normal operation

doGet

public void doGet(HttpServletRequest request,
 HttpServletResponse response)
           throws IOException,
ServletException

Description copied from class: javax.servlet.http.HttpServlet

Called by the server (via the service method) to allow a servlet to handle a GET request.

Overriding this method to support a GET request also automatically supports an HTTP HEAD request. A HEAD request is a GET request that returns no body in the response, only the request header fields.

When overriding this method, read the request data, write the response headers, get the response's Writer or output stream object, and finally, write the response data. It's best to include content type and encoding. When using a PrintWriter object to return the response, set the content type before accessing the PrintWriter object.

The servlet container must write the headers before committing the response, because in HTTP the headers must be sent before the response body.

Where possible, set the Content-Length header (with the ServletResponse.setContentLength(int) method), to allow the servlet container to use a persistent connection to return its response to the client, improving performance. The content length is automatically set if the entire response fits inside the response buffer.

When using HTTP 1.1 chunked encoding (which means that the response has a Transfer-Encoding header), do not set the Content-Length header.

The GET method should be safe, that is, without any side effects for which users are held responsible. For example, most form queries have no side effects. If a client request is intended to change stored data, the request should use some other HTTP method.

The GET method should also be idempotent, meaning that it can be safely repeated. Sometimes making a method safe also makes it idempotent. For example, repeating queries is both safe and idempotent, but buying a product online or modifying data is neither safe nor idempotent.

If the request is incorrectly formatted, doGet returns an HTTP "Bad Request" message.

Overrides:

doGet in class HttpServlet

Parameters:

request - an HttpServletRequest object that contains the request the client has made of the servlet

response - an HttpServletResponse object that contains the response the servlet sends to the client

Throws:

IOException - if an input or output error is detected when the servlet handles the GET request

ServletException - if the request for the GET could not be handled

See Also:

• ServletResponse.setContentType(java.lang.String)

getAttribute

public void getAttribute(PrintWriter writer,
 String onameStr,
 String att,
 String key)

setAttribute

public void setAttribute(PrintWriter writer,
 String onameStr,
 String att,
 String val)

listBeans

public void listBeans(PrintWriter writer,
 String qry)

isSupported

public boolean isSupported(String type)

Determines if a type is supported by the JMXProxyServlet.

Parameters:

type - The type to check

Returns:

Always returns true