Question

Using Apache’s commons-httpclient for Java, what’s the best way to add query parameters to a GetMethod instance? If I’m using PostMethod, it’s very straightforward:

PostMethod method = new PostMethod(); method.addParameter('key', 'value'); 

GetMethod doesn’t have an ‘addParameter’ method, though. I’ve discovered that this works:

GetMethod method = new GetMethod('http://www.example.com/page'); method.setQueryString(new NameValuePair[] {     new NameValuePair('key', 'value') }); 

However, most of the examples I’ve seen either hard-code the parameters directly into the URL, e.g.:

GetMethod method = new GetMethod('http://www.example.com/page?key=value'); 

or hard-code the query string, e.g.:

GetMethod method = new GetMethod('http://www.example.com/page'); method.setQueryString('?key=value'); 

Is one of these patterns to be preferred? And why the API discrepancy between PostMethod and GetMethod? And what are all those other HttpMethodParams methods intended to be used for?

Answer 1

Post methods have post parameters, but get methods do not.

Query parameters are embedded in the URL. The current version of HttpClient accepts a string in the constructor. If you wanted to add the key, value pair above, you could use:

String url = 'http://www.example.com/page?key=value'; GetMethod method = new GetMethod(url); 

A good starting tutorial can be found on the Apache Jakarta Commons page.

Update: As suggested in the comment, NameValuePair works.

GetMethod method = new GetMethod('example.com/page');  method.setQueryString(new NameValuePair[] {      new NameValuePair('key', 'value')  });