Question

I have a Servlet that sends back a JSON Object and I would like to use this servlet in another Java project. I have this method that gets me the results:

public JSONArray getSQL(String aServletURL)
{
 JSONArray toReturn = null;
 String returnString = "";
 try
 {
    URL myUrl = new URL(aServletURL);
        URLConnection conn = myUrl.openConnection();
        conn.setDoOutput(true);
        BufferedReader in = new BufferedReader( new InputStreamReader( conn.getInputStream() ) );
        String s;
        while ((s = in.readLine()) != null )
         returnString += s;
        in.close();

        toReturn = new JSONArray(returnString);
 }
 catch(Exception e)
 {
    return new JSONArray();
 }
        return toReturn;
}

This works pretty will, but the problem I am facing is the following: When I do several simultaneous requests, the results get mixed up and I sometimes get a Response that does not match the request I send.

我怀疑这个问题与我回过来的方式有关: 阅读者阅读了该链接的InputStream的引力。

How can I make sure that I get one reques -> one corresponding reply ? Is there a better way to retrieve my JSON object from my servlet ?

Cheers, Tim

Answer 1

如果我同时提出几项要求,结果会好坏参半,我有时得到的反应与我提出的要求不符。

Your servlet is not thread safe. I d bet that you ve improperly assigned request scoped data either directly or indirectly as instance or class variables of the servlet. This is a common beginner s mistake.

Carefully read this How do servlets work? Instantiation, sessions, shared variables and multithreading and fix your servlet code accordingly. The problem is not in the URLConnection code shown so far, although it indicates that you re doing exactly the same job in both doGet() and doPost(), which in turn is already a smell as to how the servlet is designed.

Answer 2

在删除<条码>查询时,你只使用该链接作为投入使用,因此,你应不使用。

HttpClient, 替代试验使用

友情链接