通过POST方法轻松发送HTTP参数

小开

最佳答案

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 );
}

小开

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!

小开

我无法让艾伦的例子实际做这个帖子，所以我最终得到了这个:

String urlParameters = "param1=a&param2=b&param3=c";
URL url = new URL("http://example.com/index.php");
URLConnection conn = url.openConnection();


conn.setDoOutput(true);


OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());


writer.write(urlParameters);
writer.flush();


String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));


while ((line = reader.readLine()) != null) {
System.out.println(line);
}
writer.close();
reader.close();

小开

我发现HttpURLConnection使用起来非常麻烦。你必须写大量样板，容易出错的代码。我需要一个轻量级包装为我的Android项目，并提出了一个库，你也可以使用:< a href = " http://hgoebl.github。io / DavidWebb noreferrer“rel = > DavidWebb < / >。

上面的例子可以这样写:

Webb webb = Webb.create();
webb.post("http://example.com/index.php")
.param("param1", "a")
.param("param2", "b")
.param("param3", "c")
.ensureSuccess()
.asVoid();

您可以在提供的链接上找到备选库的列表。

小开

下面是一个简单的例子，提交一个表单，然后将结果页面转储到System.out。当然，要适当地更改URL和POST参数:

import java.io.*;
import java.net.*;
import java.util.*;


class Test {
public static void main(String[] args) throws Exception {
URL url = new URL("http://example.net/new-message.php");
Map<String,Object> params = new LinkedHashMap<>();
params.put("name", "Freddie the Fish");
params.put("email", "fishie@seamail.example.com");
params.put("reply_to_thread", 10394);
params.put("message", "Shark attacks in Botany Bay have gotten out of control. We need more defensive dolphins to protect the schools here, but Mayor Porpoise is too busy stuffing his snout with lobsters. He's so shellfish.");


StringBuilder postData = new StringBuilder();
for (Map.Entry<String,Object> param : params.entrySet()) {
if (postData.length() != 0) postData.append('&');
postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
}
byte[] postDataBytes = postData.toString().getBytes("UTF-8");


HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
conn.setDoOutput(true);
conn.getOutputStream().write(postDataBytes);


Reader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));


for (int c; (c = in.read()) >= 0;)
System.out.print((char)c);
}
}

如果你想将结果作为String而不是直接输出，请执行以下操作:

        StringBuilder sb = new StringBuilder();
for (int c; (c = in.read()) >= 0;)
sb.append((char)c);
String response = sb.toString();

小开

import java.net.*;


public class Demo{


public static void main(){


String data = "data=Hello+World!";
URL url = new URL("http://localhost:8084/WebListenerServer/webListener");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setDoOutput(true);
con.getOutputStream().write(data.getBytes("UTF-8"));
con.getInputStream();


}


}

小开

我也有同样的问题。我想通过POST发送数据。我使用以下代码:

    URL url = new URL("http://example.com/getval.php");
Map<String,Object> params = new LinkedHashMap<>();
params.put("param1", param1);
params.put("param2", param2);


StringBuilder postData = new StringBuilder();
for (Map.Entry<String,Object> param : params.entrySet()) {
if (postData.length() != 0) postData.append('&');
postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
}
String urlParameters = postData.toString();
URLConnection conn = url.openConnection();


conn.setDoOutput(true);


OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());


writer.write(urlParameters);
writer.flush();


String result = "";
String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));


while ((line = reader.readLine()) != null) {
result += line;
}
writer.close();
reader.close()
System.out.println(result);

我使用Jsoup进行解析:

    Document doc = Jsoup.parseBodyFragment(value);
Iterator<Element> opts = doc.select("option").iterator();
for (;opts.hasNext();) {
Element item = opts.next();
if (item.hasAttr("value")) {
System.out.println(item.attr("value"));
}
}

小开

似乎你还必须调用__abc0“至少一次”(以及setDoOutput(true))才能将其视为POST。

所以最低要求的代码是:

    URL url = new URL(urlString);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//connection.setRequestMethod("POST"); this doesn't seem to do anything at all..so not useful
connection.setDoOutput(true); // set it to POST...not enough by itself however, also need the getOutputStream call...
connection.connect();
connection.getOutputStream().close();

令人惊讶的是，你甚至可以在urlString中使用“GET”样式参数。尽管这可能会让事情变得复杂。

显然，你也可以使用NameValuePair。

小开

试试这个模式:

public static PricesResponse getResponse(EventRequestRaw request) {


// String urlParameters  = "param1=a&param2=b&param3=c";
String urlParameters = Piping.serialize(request);


HttpURLConnection conn = RestClient.getPOSTConnection(endPoint, urlParameters);


PricesResponse response = null;


try {
// POST
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();


// RESPONSE
BufferedReader reader = new BufferedReader(new InputStreamReader((conn.getInputStream()), StandardCharsets.UTF_8));
String json = Buffering.getString(reader);
response = (PricesResponse) Piping.deserialize(json, PricesResponse.class);


writer.close();
reader.close();


} catch (Exception e) {
e.printStackTrace();
}


conn.disconnect();


System.out.println("PricesClient: " + response.toString());


return response;
}


public static HttpURLConnection getPOSTConnection(String endPoint, String urlParameters) {


return RestClient.getConnection(endPoint, "POST", urlParameters);


}




public static HttpURLConnection getConnection(String endPoint, String method, String urlParameters) {


System.out.println("ENDPOINT " + endPoint + " METHOD " + method);
HttpURLConnection conn = null;


try {
URL url = new URL(endPoint);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod(method);
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "text/plain");


} catch (IOException e) {
e.printStackTrace();
}


return conn;
}

小开

这里我发送jsonobject作为参数//jsonobject={"name":"lucifer"，"pass":"abc"}//serverUrl = "http://192.168.100.12/testing" //主机=192.168.100.12

  public static String getJson(String serverUrl,String host,String jsonobject){


StringBuilder sb = new StringBuilder();


String http = serverUrl;


HttpURLConnection urlConnection = null;
try {
URL url = new URL(http);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setUseCaches(false);
urlConnection.setConnectTimeout(50000);
urlConnection.setReadTimeout(50000);
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Host", host);
urlConnection.connect();
//You Can also Create JSONObject here
OutputStreamWriter out = new OutputStreamWriter(urlConnection.getOutputStream());
out.write(jsonobject);// here i sent the parameter
out.close();
int HttpResult = urlConnection.getResponseCode();
if (HttpResult == HttpURLConnection.HTTP_OK) {
BufferedReader br = new BufferedReader(new InputStreamReader(
urlConnection.getInputStream(), "utf-8"));
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
Log.e("new Test", "" + sb.toString());
return sb.toString();
} else {
Log.e(" ", "" + urlConnection.getResponseMessage());
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (urlConnection != null)
urlConnection.disconnect();
}
return null;
}

小开

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;
}

小开

我用Boann的答案创建了一个更灵活的查询字符串构建器，支持列表和数组，就像php的http_build_query方法一样:

public static byte[] httpBuildQueryString(Map<String, Object> postsData) throws UnsupportedEncodingException {
StringBuilder postData = new StringBuilder();
for (Map.Entry<String,Object> param : postsData.entrySet()) {
if (postData.length() != 0) postData.append('&');


Object value = param.getValue();
String key = param.getKey();


if(value instanceof Object[] || value instanceof List<?>)
{
int size = value instanceof Object[] ? ((Object[])value).length : ((List<?>)value).size();
for(int i = 0; i < size; i++)
{
Object val = value instanceof Object[] ? ((Object[])value)[i] : ((List<?>)value).get(i);
if(i>0) postData.append('&');
postData.append(URLEncoder.encode(key + "[" + i + "]", "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(val), "UTF-8"));
}
}
else
{
postData.append(URLEncoder.encode(key, "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(value), "UTF-8"));
}
}
return postData.toString().getBytes("UTF-8");
}

小开

我已经阅读了上面的答案，并创建了一个实用工具类来简化HTTP请求。我希望它能帮助你。

方法调用

  // send params with Hash Map
HashMap<String, String> params = new HashMap<String, String>();
params.put("email","me@example.com");
params.put("password","12345");


//server url
String url = "http://www.example.com";


// static class "HttpUtility" with static method "newRequest(url,method,callback)"
HttpUtility.newRequest(url,HttpUtility.METHOD_POST,params, new HttpUtility.Callback() {
@Override
public void OnSuccess(String response) {
// on success
System.out.println("Server OnSuccess response="+response);
}
@Override
public void OnError(int status_code, String message) {
// on error
System.out.println("Server OnError status_code="+status_code+" message="+message);
}
});

实用程序类

import java.io.*;
import java.net.*;
import java.util.HashMap;
import java.util.Map;
import static java.net.HttpURLConnection.HTTP_OK;


public class HttpUtility {


public static final int METHOD_GET = 0; // METHOD GET
public static final int METHOD_POST = 1; // METHOD POST


// Callback interface
public interface Callback {
// abstract methods
public void OnSuccess(String response);
public void OnError(int status_code, String message);
}
// static method
public static void newRequest(String web_url, int method, HashMap < String, String > params, Callback callback) {


// thread for handling async task
new Thread(new Runnable() {
@Override
public void run() {
try {
String url = web_url;
// write GET params,append with url
if (method == METHOD_GET && params != null) {
for (Map.Entry < String, String > item: params.entrySet()) {
String key = URLEncoder.encode(item.getKey(), "UTF-8");
String value = URLEncoder.encode(item.getValue(), "UTF-8");
if (!url.contains("?")) {
url += "?" + key + "=" + value;
} else {
url += "&" + key + "=" + value;
}
}
}


HttpURLConnection urlConnection = (HttpURLConnection) new URL(url).openConnection();
urlConnection.setUseCaches(false);
urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); // handle url encoded form data
urlConnection.setRequestProperty("charset", "utf-8");
if (method == METHOD_GET) {
urlConnection.setRequestMethod("GET");
} else if (method == METHOD_POST) {
urlConnection.setDoOutput(true); // write POST params
urlConnection.setRequestMethod("POST");
}


//write POST data
if (method == METHOD_POST && params != null) {
StringBuilder postData = new StringBuilder();
for (Map.Entry < String, String > item: params.entrySet()) {
if (postData.length() != 0) postData.append('&');
postData.append(URLEncoder.encode(item.getKey(), "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(item.getValue()), "UTF-8"));
}
byte[] postDataBytes = postData.toString().getBytes("UTF-8");
urlConnection.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
urlConnection.getOutputStream().write(postDataBytes);


}
// server response code
int responseCode = urlConnection.getResponseCode();
if (responseCode == HTTP_OK && callback != null) {
BufferedReader reader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
StringBuilder response = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
response.append(line);
}
// callback success
callback.OnSuccess(response.toString());
reader.close(); // close BufferReader
} else if (callback != null) {
// callback error
callback.OnError(responseCode, urlConnection.getResponseMessage());
}


urlConnection.disconnect(); // disconnect connection
} catch (IOException e) {
e.printStackTrace();
if (callback != null) {
// callback error
callback.OnError(500, e.getLocalizedMessage());
}
}
}
}).start(); // start thread
}
}

小开

我强烈推荐构建在apache http api上的http请求。

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);
}

对于一般发送后请求http请求:阅读文档，看到我的答案HTTP POST请求与JSON字符串在JAVA，用Java发送HTTP POST请求， HTTP POST在Java中使用JSON

小开

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()方法使用在我们的数据Post在url和获得响应。

 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());


}


}

小开

这个答案涵盖了使用自定义Java POJO的POST调用的特定情况。

使用Gson的maven依赖项将Java对象序列化为JSON。

使用下面的依赖项安装Gson。

<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.5</version>
<scope>compile</scope>
</dependency>

对于那些使用gradle的人可以使用下面的

dependencies {
implementation 'com.google.code.gson:gson:2.8.5'
}

使用的其他导入:

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.*;
import org.apache.http.impl.client.CloseableHttpClient;
import com.google.gson.Gson;

现在，我们可以继续使用Apache提供的HttpPost

private CloseableHttpClient httpclient = HttpClients.createDefault();
HttpPost httppost = new HttpPost("https://example.com");


Product product = new Product(); //custom java object to be posted as Request Body
Gson gson = new Gson();
String client = gson.toJson(product);


httppost.setEntity(new StringEntity(client, ContentType.APPLICATION_JSON));
httppost.setHeader("RANDOM-HEADER", "headervalue");
//Execute and get the response.
HttpResponse response = null;
try {
response = httpclient.execute(httppost);
} catch (IOException e) {
throw new InternalServerErrorException("Post fails");
}
Response.Status responseStatus = Response.Status.fromStatusCode(response.getStatusLine().getStatusCode());
return Response.status(responseStatus).build();

上面的代码将返回从POST调用接收到的响应代码

小开

对于那些使用$_POST在php页面上接收请求的问题，因为你期望键值对:

虽然所有的答案都很有帮助，但我对实际发布哪个字符串缺乏一些基本的了解，因为在我使用的旧apache HttpClient中

new UrlEncodedFormEntity(nameValuePairs); (Java)

然后可以在php中使用$_POST获取键值对。

据我的理解，现在已经在发布之前手动构建该字符串。所以字符串应该是这样的

val data = "key1=val1&key2=val2"

而是只是把它添加到它被张贴的url(在头)。

另一种方法是使用json-string:

val data = "{\"key1\":\"val1\",\"key2\":\"val2\"}" // {"key1":"val1","key2":"val2"}

然后把它拉到php中，不需要$_POST:

$json_params = file_get_contents('php://input');
// echo_p("Data: $json_params");
$data = json_decode($json_params, true);

下面是Kotlin中的示例代码:

class TaskDownloadTest : AsyncTask<Void, Void, Void>() {
override fun doInBackground(vararg params: Void): Void? {
var urlConnection: HttpURLConnection? = null


try {


val postData = JsonObject()
postData.addProperty("key1", "val1")
postData.addProperty("key2", "val2")


// reformat json to key1=value1&key2=value2
// keeping json because I may change the php part to interpret json requests, could be a HashMap instead
val keys = postData.keySet()
var request = ""
keys.forEach { key ->
// Log.i("data", key)
request += "$key=${postData.get(key)}&"
}
request = request.replace("\"", "").removeSuffix("&")
val requestLength = request.toByteArray().size
// Warning in Android 9 you need to add a line in the application part of the manifest: android:usesCleartextTraffic="true"
// https://stackoverflow.com/questions/45940861/android-8-cleartext-http-traffic-not-permitted
val url = URL("http://10.0.2.2/getdata.php")
urlConnection = url.openConnection() as HttpURLConnection
// urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded") // apparently default
// Not sure what these are for, I do not use them
// urlConnection.setRequestProperty("Content-Type", "application/json")
// urlConnection.setRequestProperty("Key","Value")
urlConnection.readTimeout = 5000
urlConnection.connectTimeout = 5000
urlConnection.requestMethod = "POST"
urlConnection.doOutput = true
// urlConnection.doInput = true
urlConnection.useCaches = false
urlConnection.setFixedLengthStreamingMode(requestLength)
// urlConnection.setChunkedStreamingMode(0) // if you do not want to handle request length which is fine for small requests


val out = urlConnection.outputStream
val writer = BufferedWriter(
OutputStreamWriter(
out, "UTF-8"
)
)
writer.write(request)
// writer.write("{\"key1\":\"val1\",\"key2\":\"val2\"}") // {"key1":"val1","key2":"val2"} JsonFormat or just postData.toString() for $json_params=file_get_contents('php://input'); json_decode($json_params, true); in php
// writer.write("key1=val1&key2=val2") // key=value format for $_POST in php
writer.flush()
writer.close()
out.close()


val code = urlConnection.responseCode
if (code != 200) {
throw IOException("Invalid response from server: $code")
}


val rd = BufferedReader(
InputStreamReader(
urlConnection.inputStream
)
)
var line = rd.readLine()
while (line != null) {
Log.i("data", line)
line = rd.readLine()
}
} catch (e: Exception) {
e.printStackTrace()
} finally {
urlConnection?.disconnect()
}


return null
}
}

小开

现在我必须做一个HTTP请求类，它可能不是最有效的类，但它工作。我从这个页面中收集了一些代码，使其更加动态任何需要完整代码的人，我在下面附上了它。关于如何使用它的例子，你可以看看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());
}
}