Question

I am using JBoss 6.0. I am running a simple webserver using the jboss.resteasy library to provide simple XML responses to HTTP requests.

I have:
– A server
– A simple Java Client that creates a GET request

Now the thing is, if I use the browser to access the URL, I get the wanted XML. But if I use my Java client, which has the following code:

//Register the fake instrument
GetMethod get = new GetMethod("http:/localhost:8080/"+PROJECT_NAME+"/webserver/registerInstrument/?name=FakeClient&value=0");
HttpClient client = new HttpClient();

try {
    int status = client.executeMethod(get);
} catch (HttpException e) {
    System.out.println("[FakeClient] HttpException executing AddInstrument GET request: "+e);
} catch (IOException e) {
    System.out.println("[FakeClient] IOException executing AddInstrument GET request: "+e);
}

Then I get the following exception:

log4j:WARN No appenders could be found for logger (org.apache.commons.httpclient.params.DefaultHttpParams).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" java.lang.IllegalArgumentException: Host name may not be null
at org.apache.commons.httpclient.HttpHost.<init>(HttpHost.java:68)
at org.apache.commons.httpclient.HttpHost.<init>(HttpHost.java:107)
at org.apache.commons.httpclient.HttpMethodBase.setURI(HttpMethodBase.java:280)
at org.apache.commons.httpclient.HttpMethodBase.<init>(HttpMethodBase.java:220)
at org.apache.commons.httpclient.methods.GetMethod.<init>(GetMethod.java:89)
at client.FakeClient.<init>(FakeClient.java:30)
at client.FakeClient.main(FakeClient.java:22)

At first I thought this could be a problem with the JBoss logging, but if I access the URL through the browser, I obtain the desired XML with no problems.

Is this a problem with the Java client application?

Thank you

Answer 1

The ‘log4j:WARN’ is just a warning. It has nothing do to with the actual exception being thrown.

The exception message states that ‘Host name may not be null’. This clearly indicates that there is something wrong the the hostname. And looking at you code, I can spot one error.

You need to add an extra forward slash:

GetMethod get = new GetMethod("http://localhost:8080/" ...