How to add parameters to a HTTP GET request in And

问题:

I have a HTTP GET request that I am attempting to send. I tried adding the parameters to this request by first creating a BasicHttpParams object and adding the parameters to that object, then calling setParams( basicHttpParms ) on my HttpGet object. This method fails. But if I manually add my parameters to my URL (i.e. append ?param1=value1&param2=value2) it succeeds.

I know I\'m missing something here and any help would be greatly appreciated.

回答1:

I use a List of NameValuePair and URLEncodedUtils to create the url string I want.

protected String addLocationToUrl(String url){
    if(!url.endsWith(\"?\"))
        url += \"?\";

    List<NameValuePair> params = new LinkedList<NameValuePair>();

    if (lat != 0.0 && lon != 0.0){
        params.add(new BasicNameValuePair(\"lat\", String.valueOf(lat)));
        params.add(new BasicNameValuePair(\"lon\", String.valueOf(lon)));
    }

    if (address != null && address.getPostalCode() != null)
        params.add(new BasicNameValuePair(\"postalCode\", address.getPostalCode()));
    if (address != null && address.getCountryCode() != null)
        params.add(new BasicNameValuePair(\"country\",address.getCountryCode()));

    params.add(new BasicNameValuePair(\"user\", agent.uniqueId));

    String paramString = URLEncodedUtils.format(params, \"utf-8\");

    url += paramString;
    return url;
}

回答2:

To build uri with get parameters, Uri.Builder provides a more effective way.

Uri uri = new Uri.Builder()
    .scheme(\"http\")
    .authority(\"foo.com\")
    .path(\"someservlet\")
    .appendQueryParameter(\"param1\", foo)
    .appendQueryParameter(\"param2\", bar)
    .build();

回答3:

As of HttpComponents 4.2+ there is a new class URIBuilder, which provides convenient way for generating URIs.

You can use either create URI directly from String URL:

List<NameValuePair> listOfParameters = ...;

URI uri = new URIBuilder(\"http://example.com:8080/path/to/resource?mandatoryParam=someValue\")
    .addParameter(\"firstParam\", firstVal)
    .addParameter(\"secondParam\", secondVal)
    .addParameters(listOfParameters)
    .build();

Otherwise, you can specify all parameters explicitly:

URI uri = new URIBuilder()
    .setScheme(\"http\")
    .setHost(\"example.com\")
    .setPort(8080)
    .setPath(\"/path/to/resource\")
    .addParameter(\"mandatoryParam\", \"someValue\")
    .addParameter(\"firstParam\", firstVal)
    .addParameter(\"secondParam\", secondVal)
    .addParameters(listOfParameters)
    .build();

Once you have created URI object, then you just simply need to create HttpGet object and perform it:

//create GET request
HttpGet httpGet = new HttpGet(uri);
//perform request
httpClient.execute(httpGet ...//additional parameters, handle response etc.

回答4:

The method

setParams() 

like

httpget.getParams().setParameter(\"http.socket.timeout\", new Integer(5000));

only adds HttpProtocol parameters.

To execute the httpGet you should append your parameters to the url manually

HttpGet myGet = new HttpGet(\"http://foo.com/someservlet?param1=foo&param2=bar\");

or use the post request the difference between get and post requests are explained here, if you are interested

回答5:

List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair(\"param1\",\"value1\");

String query = URLEncodedUtils.format(params, \"utf-8\");

URI url = URIUtils.createURI(scheme, userInfo, authority, port, path, query, fragment); //can be null
HttpGet httpGet = new HttpGet(url);

URI javadoc

Note: url = new URI(...) is buggy

回答6:

    HttpClient client = new DefaultHttpClient();

    Uri.Builder builder = Uri.parse(url).buildUpon();

    for (String name : params.keySet()) {
        builder.appendQueryParameter(name, params.get(name).toString());
    }

    url = builder.build().toString();
    HttpGet request = new HttpGet(url);
    HttpResponse response = client.execute(request);
    return EntityUtils.toString(response.getEntity(), \"UTF-8\");

回答7:

If you have constant URL I recommend use simplified http-request built on apache http.

You can build your client as following:

private filan static HttpRequest<YourResponseType> httpRequest = 
                   HttpRequestBuilder.createGet(yourUri,YourResponseType)
                   .build();

public void send(){
    ResponseHendler<YourResponseType> rh = 
         httpRequest.execute(param1, value1, param2, value2);

    handler.ifSuccess(this::whenSuccess).otherwise(this::whenNotSuccess);
}

public void whenSuccess(ResponseHendler<YourResponseType> rh){
     rh.ifHasContent(content -> // your code);
}

public void whenSuccess(ResponseHendler<YourResponseType> rh){
   LOGGER.error(\"Status code: \" + rh.getStatusCode() + \", Error msg: \" + rh.getErrorText());
}

Note: There are many useful methods to manipulate your response.