Http get requests fail after a few weeks

Question

All,
I have a get request to a servlet that works for a few weeks, then it will suddenly stop.
I change the code once, works,then it will fail after a few weeks.
I change the code again, works, then it will fail after a few weeks.
Servlet works like: send one request, wait, then send a second.
Here are the last 2 code iterations:
try {
        // Construct data
        String data = URLEncoder.encode("key1", "UTF-8") + "=" + URLEncoder.encode("value1", "UTF-8");
        data += "&" + URLEncoder.encode("key2", "UTF-8") + "=" + URLEncoder.encode("value2", "UTF-8");
          //String data = "";
        // Send data
        //URL url = new URL("http://localhost:8080/stocks?action=1&date=20080310");
        URL url = new URL("http://localhost:8080/stocks/monitor?action=1&date="+stringDate);
        URLConnection conn = url.openConnection();
        conn.setDoOutput(true);
        OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
        wr.write(data);
        wr.flush();
        // Get the response
        BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        //System.out.println(rd.read());
        String line;
        int count =0;
        while ((line = rd.readLine()) != null) {
            // Process line...
             System.out.println(count + line);
             count++;
        wr.close();
        rd.close();
    } catch (Exception e) {
    try {
        // Construct data
        String data = URLEncoder.encode("key1", "UTF-8") + "=" + URLEncoder.encode("value1", "UTF-8");
        data += "&" + URLEncoder.encode("key2", "UTF-8") + "=" + URLEncoder.encode("value2", "UTF-8");
         //String data = "";
        // Send data
        URL url = new URL("http://localhost:8080/stocks/monitor?action=2");
        URLConnection conn = url.openConnection();
        conn.setDoOutput(true);
        OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
        wr.write(data);
        wr.flush();
        // Get the response
        BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        int count =0;
        while ((line = rd.readLine()) != null) {
            // Process line...
             System.out.println(count + line);
             count++;
        wr.close();
        rd.close();
    } catch (Exception e) {
    }I send this request twice with different params
public static String sendGetRequest(String endpoint, String requestParameters)
String result = null;
if (endpoint.startsWith("http://"))
// Send a GET request to the servlet
try
// Construct data
StringBuffer data = new StringBuffer();
// Send data
String urlStr = endpoint;
if (requestParameters != null && requestParameters.length () > 0)
urlStr += "?" + requestParameters;
URL url = new URL(urlStr);
URLConnection conn = url.openConnection ();
// Get the response
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuffer sb = new StringBuffer();
String line;
while ((line = rd.readLine()) != null)
sb.append(line);
rd.close();
result = sb.toString();
} catch (Exception e)
e.printStackTrace();
return result;
}Any ideas?
Edited by: iketurna on Mar 13, 2008 7:21 AM

Answer 1

You appear to have empty catch blocks. Which means you don't get the error message that would tell you what is failing.
Put in code that logs the exception and the stack trace of the exception. If you can't figure out the error message, post it here.
You should be closing streams in finally statements. Otherwise they might not get closed when there is an error -> you leak descriptors -> you run out of descriptors -> every stream open will fail -> more errors -> more descriptors get leaked -> etc -> everything stops working. Always do it like this:
    WhateverStream out = null;
    try {
        out = ...;
        ...use out...;
    } finally {
        try {
            if (out != null) out.close();
       } catch (IOException e) { ...log it... }
    }