通过POST方法轻松发送HTTP参数

我成功地使用这段代码通过GET方法发送带有一些参数的HTTP请求

void sendRequest(String request)
{
    // i.e.: request = "http://example.com/index.php?param1=a&param2=b&param3=c";
    URL url = new URL(request); 
    HttpURLConnection connection = (HttpURLConnection) url.openConnection();           
    connection.setDoOutput(true); 
    connection.setInstanceFollowRedirects(false); 
    connection.setRequestMethod("GET"); 
    connection.setRequestProperty("Content-Type", "text/plain"); 
    connection.setRequestProperty("charset", "utf-8");
    connection.connect();
}

现在我可能需要通过POST方法发送参数(即param1, param2, param3)，因为它们非常长。我想添加一个额外的参数，该方法(即字符串httpMethod)。

我怎样才能尽可能少地更改上面的代码，以便能够通过GET或POST发送参数?

我希望情况会有所改变

connection.setRequestMethod("GET");

connection.setRequestMethod("POST");

可以完成这个任务，但是参数仍然通过GET方法发送。

HttpURLConnection有任何方法可以帮助吗? 有什么有用的Java构造吗?

任何帮助都将不胜感激。

当前回答

我强烈推荐构建在apache http api上的http-request。

对于你的案例，你可以看到例子:

private static final HttpRequest<String.class> HTTP_REQUEST = 
      HttpRequestBuilder.createPost("http://example.com/index.php", String.class)
           .responseDeserializer(ResponseDeserializer.ignorableDeserializer())
           .build();

public void sendRequest(String request){
     String parameters = request.split("\\?")[1];
     ResponseHandler<String> responseHandler = 
            HTTP_REQUEST.executeWithQuery(parameters);

   System.out.println(responseHandler.getStatusCode());
   System.out.println(responseHandler.get()); //prints response body
}

如果您对响应体不感兴趣

private static final HttpRequest<?> HTTP_REQUEST = 
     HttpRequestBuilder.createPost("http://example.com/index.php").build();

public void sendRequest(String request){
     ResponseHandler<String> responseHandler = 
           HTTP_REQUEST.executeWithQuery(parameters);
}

对于一般发送post请求与HTTP -request:阅读文档，看到我的答案HTTP post请求与JSON字符串在JAVA，发送HTTP post请求在JAVA, HTTP post使用JSON在JAVA

2017-09-24 22:23:30

其他回答

在GET请求中，参数作为URL的一部分发送。

在POST请求中，参数作为请求体发送，位于请求头之后。

要使用HttpURLConnection进行POST，需要在打开连接后将参数写入连接。

这段代码应该让你开始:

String urlParameters  = "param1=a&param2=b&param3=c";
byte[] postData       = urlParameters.getBytes( StandardCharsets.UTF_8 );
int    postDataLength = postData.length;
String request        = "http://example.com/index.php";
URL    url            = new URL( request );
HttpURLConnection conn= (HttpURLConnection) url.openConnection();           
conn.setDoOutput( true );
conn.setInstanceFollowRedirects( false );
conn.setRequestMethod( "POST" );
conn.setRequestProperty( "Content-Type", "application/x-www-form-urlencoded"); 
conn.setRequestProperty( "charset", "utf-8");
conn.setRequestProperty( "Content-Length", Integer.toString( postDataLength ));
conn.setUseCaches( false );
try( DataOutputStream wr = new DataOutputStream( conn.getOutputStream())) {
   wr.write( postData );
}

2010-11-17 15:40:04

现在我要做一个HTTP请求类，它可能不是最有效的类，但它可以工作。我从这个页面中收集了一些代码，并使其更加动态。

任何需要完整代码的人，我在下面附上了它。关于如何使用它的示例，您可以查看main方法。

此外，如果你愿意改进在线课程，非常欢迎你来帮助我使这门课变得更好。

import java.net.*;
import java.util.*;
import java.nio.charset.*;
import java.io.*;
  
public class HttpRequest {
    
    
    String result = "";
    
    HttpRequest(String _url, String _method, Map<String, String> _postData, String _contentType) {
        
        try {
            URL url = new URL( _url );
            URLConnection con = url.openConnection();
            HttpURLConnection http = (HttpURLConnection)con;
            http.setRequestMethod(_method); // PUT is another valid option
            http.setDoOutput(true);         
            
            StringJoiner sj = new StringJoiner("&");
            for(Map.Entry<String,String> entry : _postData.entrySet())
                sj.add(URLEncoder.encode(entry.getKey(), "UTF-8") + "=" + entry.getValue());
                //sj.add(URLEncoder.encode(entry.getKey(), "UTF-8") + "=" + URLEncoder.encode(entry.getValue()));
            byte[] out = sj.toString().getBytes(StandardCharsets.UTF_8);
            int length = out.length;
            http.setFixedLengthStreamingMode(length);
            http.setRequestProperty("Content-Type", _contentType);
            http.setRequestProperty( "charset", "utf-8");
            http.setRequestProperty( "Content-Length", Integer.toString( length ));
            http.setInstanceFollowRedirects( false );
            http.setUseCaches( false );
            http.connect();
            try(OutputStream os = http.getOutputStream()) {
                os.write(out);
            }
            if (http.getResponseCode() == HttpURLConnection.HTTP_OK) {
                try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(http.getInputStream()))) {
                String line;
                while ((line = bufferedReader.readLine()) != null) {
                  result = result + line;
                }
            }
          } else {
            System.out.println("Bad response!");
          }
        }catch (IOException e) {
            // writing exception to log
            e.printStackTrace();
        }
        
    }
    
    
    HttpRequest(String _url, String _method, Map<String, String> _postData) {
        this(_url, _method, _postData, "text/html");
    }
    
    HttpRequest(String _url, String _method) {
        this(_url, _method, new HashMap<String, String>());
    }
    
    HttpRequest(String _url) {
        this(_url, "GET");
    }
    
    
    public String toString() {
        return result;
    }
    
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Map<String, String> postData = new HashMap<String, String>();
        postData.putIfAbsent("email", "test@test.com");
        postData.putIfAbsent("password", "test");
        
        HttpRequest result = new HttpRequest("https://httpbin.org/anything", "POST", postData, "application/x-www-form-urlencoded");
        System.out.println(result.toString());
    }
}

2021-05-09 20:36:27

GET和POST方法设置如下…两种类型的api调用1)get()和2)post()。Get()方法从API json数组中获取值& post()方法在url中的数据post中使用并获得响应。

 public class HttpClientForExample {

    private final String USER_AGENT = "Mozilla/5.0";

    public static void main(String[] args) throws Exception {

        HttpClientExample http = new HttpClientExample();

        System.out.println("Testing 1 - Send Http GET request");
        http.sendGet();

        System.out.println("\nTesting 2 - Send Http POST request");
        http.sendPost();

    }

    // HTTP GET request
    private void sendGet() throws Exception {

        String url = "http://www.google.com/search?q=developer";

        HttpClient client = new DefaultHttpClient();
        HttpGet request = new HttpGet(url);

        // add request header
        request.addHeader("User-Agent", USER_AGENT);

        HttpResponse response = client.execute(request);

        System.out.println("\nSending 'GET' request to URL : " + url);
        System.out.println("Response Code : " + 
                       response.getStatusLine().getStatusCode());

        BufferedReader rd = new BufferedReader(
                       new InputStreamReader(response.getEntity().getContent()));

        StringBuffer result = new StringBuffer();
        String line = "";
        while ((line = rd.readLine()) != null) {
            result.append(line);
        }

        System.out.println(result.toString());

    }

    // HTTP POST request
    private void sendPost() throws Exception {

        String url = "https://selfsolve.apple.com/wcResults.do";

        HttpClient client = new DefaultHttpClient();
        HttpPost post = new HttpPost(url);

        // add header
        post.setHeader("User-Agent", USER_AGENT);

        List<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
        urlParameters.add(new BasicNameValuePair("sn", "C02G8416DRJM"));
        urlParameters.add(new BasicNameValuePair("cn", ""));
        urlParameters.add(new BasicNameValuePair("locale", ""));
        urlParameters.add(new BasicNameValuePair("caller", ""));
        urlParameters.add(new BasicNameValuePair("num", "12345"));

        post.setEntity(new UrlEncodedFormEntity(urlParameters));

        HttpResponse response = client.execute(post);
        System.out.println("\nSending 'POST' request to URL : " + url);
        System.out.println("Post parameters : " + post.getEntity());
        System.out.println("Response Code : " + 
                                    response.getStatusLine().getStatusCode());

        BufferedReader rd = new BufferedReader(
                        new InputStreamReader(response.getEntity().getContent()));

        StringBuffer result = new StringBuffer();
        String line = "";
        while ((line = rd.readLine()) != null) {
            result.append(line);
        }

        System.out.println(result.toString());

    }

}

2018-08-20 05:48:42

我看到一些其他的答案给出了另一种选择，我个人认为直觉上你在做正确的事情;)不好意思，在devoxx上，有几个演讲者一直在抱怨这种事情。

这就是为什么我个人使用Apache的HTTPClient/HttpCore库来做这类工作，我发现它们的API比Java的原生HTTP支持更容易使用。当然是YMMV了!

2010-11-17 15:40:37

你好，请使用这个类来改善你的张贴方法

public static JSONObject doPostRequest(HashMap<String, String> data, String url) {

    try {
        RequestBody requestBody;
        MultipartBuilder mBuilder = new MultipartBuilder().type(MultipartBuilder.FORM);

        if (data != null) {


            for (String key : data.keySet()) {
                String value = data.get(key);
                Utility.printLog("Key Values", key + "-----------------" + value);

                mBuilder.addFormDataPart(key, value);

            }
        } else {
            mBuilder.addFormDataPart("temp", "temp");
        }
        requestBody = mBuilder.build();


        Request request = new Request.Builder()
                .url(url)
                .post(requestBody)
                .build();

        OkHttpClient client = new OkHttpClient();
        Response response = client.newCall(request).execute();
        String responseBody = response.body().string();
        Utility.printLog("URL", url);
        Utility.printLog("Response", responseBody);
        return new JSONObject(responseBody);

    } catch (UnknownHostException | UnsupportedEncodingException e) {

        JSONObject jsonObject=new JSONObject();

        try {
            jsonObject.put("status","false");
            jsonObject.put("message",e.getLocalizedMessage());
        } catch (JSONException e1) {
            e1.printStackTrace();
        }
        Log.e(TAG, "Error: " + e.getLocalizedMessage());
    } catch (Exception e) {
        e.printStackTrace();
        JSONObject jsonObject=new JSONObject();

        try {
            jsonObject.put("status","false");
            jsonObject.put("message",e.getLocalizedMessage());
        } catch (JSONException e1) {
            e1.printStackTrace();
        }
        Log.e(TAG, "Other Error: " + e.getLocalizedMessage());
    }
    return null;
}

2016-07-22 11:54:19

通过POST方法轻松发送HTTP参数

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