您可以使用Gson库将java类转换为JSON对象。

为想要发送的变量创建一个pojo类 如上所述

{"name":"myname","age":"20"}

就变成了

class pojo1
{
   String name;
   String age;
   //generate setter and getters
}

一旦在pojo1类中设置了变量，就可以使用下面的代码发送它

String       postUrl       = "www.site.com";// put in your url
Gson         gson          = new Gson();
HttpClient   httpClient    = HttpClientBuilder.create().build();
HttpPost     post          = new HttpPost(postUrl);
StringEntity postingString = new StringEntity(gson.toJson(pojo1));//gson.tojson() converts your pojo to json
post.setEntity(postingString);
post.setHeader("Content-type", "application/json");
HttpResponse  response = httpClient.execute(post);

这些是进口

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;

和GSON

import com.google.gson.Gson;

以下是你需要做的:

获取Apache HttpClient，这将使您能够发出所需的请求 用它创建一个HttpPost请求，并添加头应用程序/x-www-form-urlencoded 创建一个StringEntity，并将JSON传递给它 执行调用

代码大致如下(你仍然需要调试它并使它工作):

// @Deprecated HttpClient httpClient = new DefaultHttpClient();
HttpClient httpClient = HttpClientBuilder.create().build();
try {
    HttpPost request = new HttpPost("http://yoururl");
    StringEntity params = new StringEntity("details={\"name\":\"xyz\",\"age\":\"20\"} ");
    request.addHeader("content-type", "application/x-www-form-urlencoded");
    request.setEntity(params);
    HttpResponse response = httpClient.execute(request);
} catch (Exception ex) {
} finally {
    // @Deprecated httpClient.getConnectionManager().shutdown(); 
}

您可以使用Gson库将java类转换为JSON对象。

为想要发送的变量创建一个pojo类 如上所述

{"name":"myname","age":"20"}

就变成了

class pojo1
{
   String name;
   String age;
   //generate setter and getters
}

一旦在pojo1类中设置了变量，就可以使用下面的代码发送它

String       postUrl       = "www.site.com";// put in your url
Gson         gson          = new Gson();
HttpClient   httpClient    = HttpClientBuilder.create().build();
HttpPost     post          = new HttpPost(postUrl);
StringEntity postingString = new StringEntity(gson.toJson(pojo1));//gson.tojson() converts your pojo to json
post.setEntity(postingString);
post.setHeader("Content-type", "application/json");
HttpResponse  response = httpClient.execute(post);

这些是进口

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;

和GSON

import com.google.gson.Gson;

对于Java 11，你可以使用新的HTTP客户端:

HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("http://localhost/api"))
    .header("Content-Type", "application/json")
    .POST(ofInputStream(() -> getClass().getResourceAsStream(
        "/some-data.json")))
    .build();

client.sendAsync(request, BodyHandlers.ofString())
    .thenApply(HttpResponse::body)
    .thenAccept(System.out::println)
    .join();

你可以使用InputStream, String, File中的发布者。将JSON转换为字符串或IS可以用Jackson完成。

你可以在Apache HTTP中使用以下代码:

String payload = "{\"name\": \"myname\", \"age\": \"20\"}";
post.setEntity(new StringEntity(payload, ContentType.APPLICATION_JSON));

response = client.execute(request);

此外，您还可以创建一个json对象，并像这样在对象中放入字段

HttpPost post = new HttpPost(URL);
JSONObject payload = new JSONObject();
payload.put("name", "myName");
payload.put("age", "20");
post.setEntity(new StringEntity(payload.toString(), ContentType.APPLICATION_JSON));

使用HttpURLConnection可能是最简单的。

http://www.xyzws.com/Javafaq/how-to-use-httpurlconnection-post-data-to-web-server/139

你将使用JSONObject或其他东西来构造JSON，但不是用来处理网络;你需要序列化它，然后将它传递给一个HttpURLConnection到POST。