curcuitbreaker/web/CircuitBreakerServletBase.java

package dk.thoerup.curcuitbreaker.web;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.*;

/**
 * This is a web interface for viewing and controlling the CircuitBreakers currently registered in CircuitBreakerManager
 * <p> 
 * To use this servlet in you .war module just create a simple servlet that extends this class (instead of HttpServlet)
 * The new custom servlet doesn't need to implement any of the standard servlet methods - its all done in this implementation.
 *  
 * <p>
 * Example:
 * <pre>
 * public class CircuitBreakerServlet extends CircuitBreakerServletBase {
 *   private static final long serialVersionUID = 1L;
 * }
 * </pre>
 * 
 * If you add a servlet init pameter to your deployment descriptor with the name 'readonly' and a integer value > 0,  you can disable the 
 * control buttons:
 * <p>
 *   &lt;init-param>&lt;param-name>readonly&lt;/param-name>&lt;param-value>1&lt;/param-value>&lt;/init-param>
 *   <!-- <init-param><param-name>readonly</param-name><param-value>1</param-value></init-param> -->
 * 
 */

public class CircuitBreakerServletBase  extends javax.servlet.http.HttpServlet  {
        
        private static final long serialVersionUID = 1L;
        
        private boolean readOnly = false;
        
        
        
        @Override
        public void init() throws ServletException {
                super.init();
                
                String readOnlyStr = getInitParameter("readonly");
                if (readOnlyStr != null && readOnlyStr.trim().length() >0) {
                        int readOnlyInt = Integer.parseInt(readOnlyStr.trim());
                        readOnly = (readOnlyInt > 0);
                }
        }

        private Command getCommand(String command) throws ServletException {
                if (command == null || command.equals("list"))
                        return new ListCircuitBreakers();
                
                if (command.equals("view"))
                        return new ViewCircuitBreaker(readOnly);
                if (command.equals("action"))
                        return new ActionCommand(readOnly);
                
                throw new ServletException("No such command:" + command);
        }

        public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
                Command cmd = getCommand( req.getParameter("command"));
                
                String response = cmd.execute(req,resp);
                
                resp.setDateHeader("Expires", 0);
                resp.setHeader("Pragma", "no-cache");
                resp.setHeader("Cache-Control", "no-cache");
                resp.setContentType("text/html");
                
                resp.getWriter().print(response);
        }

        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
                doGet(req, resp);
        }

}
1	package dk.thoerup.curcuitbreaker.web;
2
3	import java.io.IOException;
4
5	import javax.servlet.ServletException;
6	import javax.servlet.http.*;
7
8	/**
9	* This is a web interface for viewing and controlling the CircuitBreakers currently registered in CircuitBreakerManager
10	* <p>
11	* To use this servlet in you .war module just create a simple servlet that extends this class (instead of HttpServlet)
12	* The new custom servlet doesn't need to implement any of the standard servlet methods - its all done in this implementation.
13	*
14	* <p>
15	* Example:
16	* <pre>
17	* public class CircuitBreakerServlet extends CircuitBreakerServletBase {
18	* private static final long serialVersionUID = 1L;
19	* }
20	* </pre>
21	*
22	* If you add a servlet init pameter to your deployment descriptor with the name 'readonly' and a integer value > 0, you can disable the
23	* control buttons:
24	* <p>
25	* <init-param><param-name>readonly</param-name><param-value>1</param-value></init-param>
26	* <!-- <init-param><param-name>readonly</param-name><param-value>1</param-value></init-param> -->
27	*
28	*/
29
30	public class CircuitBreakerServletBase extends javax.servlet.http.HttpServlet {
31
32	private static final long serialVersionUID = 1L;
33
34	private boolean readOnly = false;
35
36
37
38	@Override
39	public void init() throws ServletException {
40	super.init();
41
42	String readOnlyStr = getInitParameter("readonly");
43	if (readOnlyStr != null && readOnlyStr.trim().length() >0) {
44	int readOnlyInt = Integer.parseInt(readOnlyStr.trim());
45	readOnly = (readOnlyInt > 0);
46	}
47	}
48
49	private Command getCommand(String command) throws ServletException {
50	if (command == null \|\| command.equals("list"))
51	return new ListCircuitBreakers();
52
53	if (command.equals("view"))
54	return new ViewCircuitBreaker(readOnly);
55	if (command.equals("action"))
56	return new ActionCommand(readOnly);
57
58	throw new ServletException("No such command:" + command);
59	}
60
61	public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
62	Command cmd = getCommand( req.getParameter("command"));
63
64	String response = cmd.execute(req,resp);
65
66	resp.setDateHeader("Expires", 0);
67	resp.setHeader("Pragma", "no-cache");
68	resp.setHeader("Cache-Control", "no-cache");
69	resp.setContentType("text/html");
70
71	resp.getWriter().print(response);
72	}
73
74	@Override
75	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
76	doGet(req, resp);
77	}
78
79	}