Thread: [jnc-users] NullPointerException in HTTPUrlConnection
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From: Avi C. <av...@gm...> - 2008-05-27 18:31:30
|
Trying to compile a simple code that creates an HTTP connection:
*
import* java.net.URL;
*
import* java.net.URLConnection;
*
public* *class* PTest {
*static* *public* *void* main(String[] args) {
URLConnection conn = *null*;
*try* {
URL url = *new* URL("http://www.apache.org/");
conn = url.openConnection();
*if* (conn == *null*) {
System.*out*.println("conn is null");
}
conn.connect();
} *catch* (Exception ex) {
ex.printStackTrace();
}
}
}
Getting NPE in the connect() part:
java.lang.NullPointerException
at gnu.java.net.protocol.http.HTTPURLConnection.connect(PTest.exe)
at PTest.main(PTest.exe)
Any ideas ?
using version 1.1.1, standard installation (other stuff work well). Running
on XP SP2 and Vista.
Thx,
Avi
|
|
From: A. 's. A. <str...@gm...> - 2008-07-15 14:18:54
|
Hi, I just had the same problem Avi Cohen reported a couple months ago.
Using a url that does not exist leads to a NPE. The code I used for testing
is almost the same:
import java.net.URL;
import java.net.URLConnection;
public class URLConnectionTest {
static public void main(String[] args) {
try {
URL u = new URL("http://www.hasdklashdklj.com/");
System.out.println(u);
URLConnection c = u.openConnection();
System.out.println(c);
c.connect();
System.out.println("done");
} catch (Exception e) {
System.out.println("nono");
e.printStackTrace();
}
}
}
Here's the setup:
JNC-1.1.1
gcc-122233
Using Windows XP
Compiling for Windows
Compiling from source
Config:
Not excluding JCE
Not optimizing
Not stripping
Not packing
All the other options are the default (new project)
Here's the output:
A. exclude JCE, add GNU regex
http://www.hasdklashdklj.com/
nono
java.lang.NullPointerException
at
java.net.URLConnection.toString(/usr/local/src/gcc/libjava/classpath/java/net/URLConnection.java:627)
at
java.io.PrintStream.println(/usr/local/src/gcc/libjava/java/io/PrintStream.java:473)
at URLConnectionTest.main(C:/DOCUME~1/andre/CONFIG~1/Temp/ccOsbaaa.jar:0)
B. not excluding JCE, not adding GNU regex (does not seem to interfer, tried
with and without)
http://www.hasdklashdklj.com/
gnu.java.net.protocol.http.HTTPURLConnection:http://www.hasdklashdklj.com/
nono
java.lang.NullPointerException
<<No stacktrace available>>
The output in eclipse is
http://www.hasdklashdklj.com/
sun.net.www.protocol.http.HttpURLConnection:http://www.hasdklashdklj.com/
nono
java.net.UnknownHostException: www.hasdklashdklj.com
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
(...)
Anybody has a workaround? I can't find a way to check the URL without using
URL.openConnection().
[]s
André.
|
|
From: Marco T. <ma...@mt...> - 2008-07-15 14:24:24
|
Hello André
André 'streeto' Amorim wrote:
> Hi, I just had the same problem Avi Cohen reported a couple months ago.
> Using a url that does not exist leads to a NPE. The code I used for
> testing is almost the same:
>
> import java.net.URL;
> import java.net.URLConnection;
>
> public class URLConnectionTest {
> static public void main(String[] args) {
> try {
> URL u = new URL("http://www.hasdklashdklj.com/");
> System.out.println(u);
> URLConnection c = u.openConnection();
> System.out.println(c);
> c.connect();
> System.out.println("done");
> } catch (Exception e) {
> System.out.println("nono");
> e.printStackTrace();
> }
> }
> }
>
> Here's the setup:
>
> JNC-1.1.1
> gcc-122233
> Using Windows XP
> Compiling for Windows
> Compiling from source
> Config:
> Not excluding JCE
> Not optimizing
> Not stripping
> Not packing
> All the other options are the default (new project)
>
> Here's the output:
>
> A. exclude JCE, add GNU regex
>
> http://www.hasdklashdklj.com/
> nono
> java.lang.NullPointerException
> at
> java.net.URLConnection.toString(/usr/local/src/gcc/libjava/classpath/java/net/URLConnection.java:627)
> at
> java.io.PrintStream.println(/usr/local/src/gcc/libjava/java/io/PrintStream.java:473)
> at URLConnectionTest.main(C:/DOCUME~1/andre/CONFIG~1/Temp/ccOsbaaa.jar:0)
>
>
> B. not excluding JCE, not adding GNU regex (does not seem to interfer,
> tried with and without)
>
> http://www.hasdklashdklj.com/
> gnu.java.net.protocol.http.HTTPURLConnection:http://www.hasdklashdklj.com/
> nono
> java.lang.NullPointerException
> <<No stacktrace available>>
>
>
> The output in eclipse is
>
> http://www.hasdklashdklj.com/
> sun.net.www.protocol.http.HttpURLConnection:http://www.hasdklashdklj.com/
> nono
> java.net.UnknownHostException: www.hasdklashdklj.com
> <http://www.hasdklashdklj.com>
> at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
> (...)
>
>
> Anybody has a workaround? I can't find a way to check the URL without
> using URL.openConnection().
maybe:
try { ... } catch(NullPointerException ex) { /* illegal url */ }
?
Marco
> []s
>
> André.
>
>
> ------------------------------------------------------------------------
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> javaCompiler-users mailing list
> jav...@li...
> https://lists.sourceforge.net/lists/listinfo/javacompiler-users
|
|
From: A. 's. A. <str...@gm...> - 2008-07-15 21:03:25
|
Marco, catching the NPE will prevent the crash in c.connect(), but the
application starts to behave strangely, and then just segfaults. I found a
workaround, you can add this line:
InetAddress addr = InetAddress.getByName(new URL("
http://bogusurl/asdf/").getHost());
This will cause an UnknownHostException if the host is unreachable. The
snippet I sent before becomes, then,
import java.net.InetAddress;
import java.net.URL;
import java.net.URLConnection;
public class URLConnectionTest {
static public void main(String[] args) {
try {
System.out.println("first try");
URL u = new URL("http://www.hasdklashdklj.com/");
System.out.println(u);
// HACK (GCJ): will throw an UnknownHostException if host is
unreachable.
@SuppressWarnings("unused")
InetAddress addr = InetAddress.getByName(u.getHost());
URLConnection c = u.openConnection();
System.out.println(c);
c.connect();
System.out.println("done");
} catch (Exception e) {
System.out.println("nono");
e.printStackTrace();
}
}
}
Hope this helps.
André.
On Tue, Jul 15, 2008 at 11:24 AM, Marco Trudel <ma...@mt...> wrote:
> Hello André
>
> André 'streeto' Amorim wrote:
>
>> Hi, I just had the same problem Avi Cohen reported a couple months ago.
>> Using a url that does not exist leads to a NPE. The code I used for testing
>> is almost the same:
>>
>> import java.net.URL;
>> import java.net.URLConnection;
>>
>> public class URLConnectionTest {
>> static public void main(String[] args) {
>> try {
>> URL u = new URL("http://www.hasdklashdklj.com/");
>> System.out.println(u);
>> URLConnection c = u.openConnection();
>> System.out.println(c);
>> c.connect();
>> System.out.println("done");
>> } catch (Exception e) {
>> System.out.println("nono");
>> e.printStackTrace();
>> }
>> }
>> }
>>
>> Here's the setup:
>>
>> JNC-1.1.1
>> gcc-122233
>> Using Windows XP
>> Compiling for Windows
>> Compiling from source
>> Config:
>> Not excluding JCE
>> Not optimizing
>> Not stripping
>> Not packing
>> All the other options are the default (new project)
>>
>> Here's the output:
>>
>> A. exclude JCE, add GNU regex
>>
>> http://www.hasdklashdklj.com/
>> nono
>> java.lang.NullPointerException
>> at
>> java.net.URLConnection.toString(/usr/local/src/gcc/libjava/classpath/java/net/URLConnection.java:627)
>> at
>> java.io.PrintStream.println(/usr/local/src/gcc/libjava/java/io/PrintStream.java:473)
>> at
>> URLConnectionTest.main(C:/DOCUME~1/andre/CONFIG~1/Temp/ccOsbaaa.jar:0)
>>
>>
>> B. not excluding JCE, not adding GNU regex (does not seem to interfer,
>> tried with and without)
>>
>> http://www.hasdklashdklj.com/
>> gnu.java.net.protocol.http.HTTPURLConnection:
>> http://www.hasdklashdklj.com/
>> nono
>> java.lang.NullPointerException
>> <<No stacktrace available>>
>>
>>
>> The output in eclipse is
>>
>> http://www.hasdklashdklj.com/
>> sun.net.www.protocol.http.HttpURLConnection:http://www.hasdklashdklj.com/
>> nono
>> java.net.UnknownHostException: www.hasdklashdklj.com <
>> http://www.hasdklashdklj.com>
>> at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
>> (...)
>>
>>
>> Anybody has a workaround? I can't find a way to check the URL without
>> using URL.openConnection().
>>
>
> maybe:
> try { ... } catch(NullPointerException ex) { /* illegal url */ }
> ?
>
>
> Marco
>
> []s
>>
>> André.
>>
>>
>> ------------------------------------------------------------------------
>>
>> -------------------------------------------------------------------------
>> This SF.Net email is sponsored by the Moblin Your Move Developer's
>> challenge
>> Build the coolest Linux based applications with Moblin SDK & win great
>> prizes
>> Grand prize is a trip for two to an Open Source event anywhere in the
>> world
>> http://moblin-contest.org/redirect.php?banner_id=100&url=/
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> javaCompiler-users mailing list
>> jav...@li...
>> https://lists.sourceforge.net/lists/listinfo/javacompiler-users
>>
>
>
|
|
From: Marco T. <ma...@mt...> - 2008-07-16 18:10:16
|
Hello André
André 'streeto' Amorim wrote:
> Marco, catching the NPE will prevent the crash in c.connect(), but the
> application starts to behave strangely, and then just segfaults.
Whew! In this case there's a serious problem, not just a non-Sun-JRE
behavior as I suspected.
> I found
> a workaround, you can add this line:
>
> InetAddress addr = InetAddress.getByName(new
> URL("http://bogusurl/asdf/").getHost());
Great, thank you!
Marco
> This will cause an UnknownHostException if the host is unreachable. The
> snippet I sent before becomes, then,
>
> import java.net.InetAddress;
> import java.net.URL;
> import java.net.URLConnection;
>
> public class URLConnectionTest {
> static public void main(String[] args) {
> try {
> System.out.println("first try");
> URL u = new URL("http://www.hasdklashdklj.com/");
> System.out.println(u);
>
> // HACK (GCJ): will throw an UnknownHostException if host is
> unreachable.
> @SuppressWarnings("unused")
> InetAddress addr = InetAddress.getByName(u.getHost());
>
> URLConnection c = u.openConnection();
> System.out.println(c);
> c.connect();
> System.out.println("done");
> } catch (Exception e) {
> System.out.println("nono");
> e.printStackTrace();
> }
> }
> }
>
> Hope this helps.
>
> André.
>
> On Tue, Jul 15, 2008 at 11:24 AM, Marco Trudel <ma...@mt...> wrote:
>
> Hello André
>
> André 'streeto' Amorim wrote:
>
> Hi, I just had the same problem Avi Cohen reported a couple
> months ago. Using a url that does not exist leads to a NPE. The
> code I used for testing is almost the same:
>
> import java.net.URL;
> import java.net.URLConnection;
>
> public class URLConnectionTest {
> static public void main(String[] args) {
> try {
> URL u = new URL("http://www.hasdklashdklj.com/");
> System.out.println(u);
> URLConnection c = u.openConnection();
> System.out.println(c);
> c.connect();
> System.out.println("done");
> } catch (Exception e) {
> System.out.println("nono");
> e.printStackTrace();
> }
> }
> }
>
> Here's the setup:
>
> JNC-1.1.1
> gcc-122233
> Using Windows XP
> Compiling for Windows
> Compiling from source
> Config:
> Not excluding JCE
> Not optimizing
> Not stripping
> Not packing
> All the other options are the default (new project)
>
> Here's the output:
>
> A. exclude JCE, add GNU regex
>
> http://www.hasdklashdklj.com/
> nono
> java.lang.NullPointerException
> at
> java.net.URLConnection.toString(/usr/local/src/gcc/libjava/classpath/java/net/URLConnection.java:627)
> at
> java.io.PrintStream.println(/usr/local/src/gcc/libjava/java/io/PrintStream.java:473)
> at
> URLConnectionTest.main(C:/DOCUME~1/andre/CONFIG~1/Temp/ccOsbaaa.jar:0)
>
>
> B. not excluding JCE, not adding GNU regex (does not seem to
> interfer, tried with and without)
>
> http://www.hasdklashdklj.com/
> gnu.java.net.protocol.http.HTTPURLConnection:http://www.hasdklashdklj.com/
> nono
> java.lang.NullPointerException
> <<No stacktrace available>>
>
>
> The output in eclipse is
>
> http://www.hasdklashdklj.com/
> sun.net.www.protocol.http.HttpURLConnection:http://www.hasdklashdklj.com/
> nono
> java.net.UnknownHostException: www.hasdklashdklj.com
> <http://www.hasdklashdklj.com> <http://www.hasdklashdklj.com>
>
> at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
> (...)
>
>
> Anybody has a workaround? I can't find a way to check the URL
> without using URL.openConnection().
>
>
> maybe:
> try { ... } catch(NullPointerException ex) { /* illegal url */ }
> ?
>
>
> Marco
>
> []s
>
> André.
>
>
> ------------------------------------------------------------------------
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move
> Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win
> great prizes
> Grand prize is a trip for two to an Open Source event anywhere
> in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> <http://moblin-contest.org/redirect.php?banner_id=100&url=/>
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> javaCompiler-users mailing list
> jav...@li...
> <mailto:jav...@li...>
> https://lists.sourceforge.net/lists/listinfo/javacompiler-users
>
>
>
>
> ------------------------------------------------------------------------
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> javaCompiler-users mailing list
> jav...@li...
> https://lists.sourceforge.net/lists/listinfo/javacompiler-users
|
|
From: Marco T. <ma...@mt...> - 2008-05-28 08:32:07
|
Hey Avi
Avi Cohen wrote:
> Trying to compile a simple code that creates an HTTP connection:
If you do not exclude JCE, your sample works.
Hope that helps
Marco
> *
>
> import
>
> * java.net.URL;*
>
> import
>
> * java.net.URLConnection;
>
> *
>
> public
>
> * *class* PTest {
>
> *static* *public* *void* main(String[] args) {
>
> URLConnection conn =
>
> *null*;
>
> *try* {
>
> URL url =
>
> *new* URL("http://www.apache.org/");
>
> conn = url.openConnection();
>
> *if* (conn == *null*) {
>
> System.
>
> /out/.println("conn is null");
>
> }
>
> conn.connect();
>
> }
>
> *catch* (Exception ex) {
>
> ex.printStackTrace();
>
> }
>
> }
>
> }
>
> Getting NPE in the connect() part:
>
> java.lang.NullPointerException
> at gnu.java.net.protocol.http.HTTPURLConnection.connect(PTest.exe)
> at PTest.main(PTest.exe)
>
> Any ideas ?
>
> using version 1.1.1, standard installation (other stuff work well).
> Running on XP SP2 and Vista.
>
> Thx,
>
> Avi
>
>
>
>
> ------------------------------------------------------------------------
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Microsoft
> Defy all challenges. Microsoft(R) Visual Studio 2008.
> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> javaCompiler-users mailing list
> jav...@li...
> https://lists.sourceforge.net/lists/listinfo/javacompiler-users
|
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