URL and HttpURLConnection need to be synchronized

Question

Hi everybody,
I'm developing a class that allows to send and to receive messages using a HttpURLConnection.
The main question is :
- I'm not sure that every time I call the method "openConnection" of an URL object, I'll get a new instance of a HttpURLConnection ?
I'll try to illustrate my problem with the next pseudo code ( I think the question I've written above arises again in the remarks of "Question1" and "Question2" of the constructor of MyURLConnection ):
* Class that tests the class I'm developing
public class ExempleURL {
String myURL = "http://myserver.aaaa.bbbb/dir1/servlet/my_servlet/"
/** This method creates a new "MyURLConnection" object with the URL "myURL". */
public StringBuffer sendMessage(StringBuffer message) throws Exception {
MyURLConnection urlCon = new MyURLConnection( myURL );
urlCon.write(message);
return urlCon.read();
* This method sends an array of "messages" and returns an array of responses. */
public StringBuffer[] testURL(StringBuffer [] arrM) throws Exception {
StringBuffer[] arrayOfResponses = new StringBuffer[ arrM.length ];
for(int i = 0; i < arrM; i++) {
arrayOfResponses[i] = sendMessage( arrM[i] );
/** The class I'm developing : this class encapsules the use of java.net.URL and
* java.net.HttpURLConnection.*/
public class MyURLConnection {
// properties : URL url; HttpURLConnection httpUrlConnection; and so on ...
/** constructor */
public MyURLConnection (String strUrl) throws MalformedURLException,IOException,Exception {
super();
// Question 1) It is creating a new instance of a URL ?
this.url = new URL(myURL);
// Question 2) It is creating a new instance of a HttpURLConnection ?
this.httpUrlConnection = (HttpURLConnection)url.openConnection();
// preparing the HttpURLConnection property.
this.httpUrlConnection.setAllowUserInteraction(true);
this.httpUrlConnection.setDoOutput(true);
this.httpUrlConnection.setDoInput(true);
this.httpUrlConnection.setDefaultUseCaches(false);
this.httpUrlConnection.setRequestMethod(this.POST);
/** This method sends the message. */
public void write(StringBuffer message) throws UnsupportedEncodingException,IOException,Exception {
OutputStreamWriter out;
out = new OutputStreamWriter( new BufferedOutputStream(
this.httpUrlConnection.getOutputStream(),
message.length()
"ASCII");
// sending the message
out.write( message.toString() );
// I'm not sure it's necessary but it works.
out.flush();
// We close the "OutputStreamWriter".
out.close();
/** This method reads the response. */
public StringBuffer read() throws IOException {
StringBuffer response = new StringBuffer("");
BufferedReader in = new BufferedReader(
new InputStreamReader(
this.httpUrlConnection.getInputStream()));
String aux;
int i = 0;
while ((aux = in.readLine()) != null) {
response.append( aux );
i++;
in.close();
return response;
} /* ****** End of pseudo-code. ****** /
Well, I think there is other question :
- Should I define the methods "write" and "read" of the MyURLConnection class as "synchronized" ?
I'm sorry, I've written a very large text but I thought this was the best way for explaining the problem. Thanks a lot !
Jose Luis Alvarez Casas

Answer 1

Thank you for your quick answers :)
There's only a question more ... in the pseudo-code that I showed in my first message, there is not any pause between the call of the method "write" and the method "read". I mean : should the code wait the method "write" has sent the message before it calls the method "read" ? Or by other hand, it isn't necessary because a suitable exception will arise ?
Thanks again,
Jose Luis
P.D. : I suppose that you have already got the 8 Duke Dollars :)