Question

我有以下内容：

final String url = "http://example.com";

final HttpClient httpClient = new HttpClient();
final PostMethod postMethod = new PostMethod(url);
postMethod.addRequestHeader("Content-Type", "application/json");
postMethod.addParameters(new NameValuePair[]{
        new NameValuePair("name", "value)
});
httpClient.executeMethod(httpMethod);
postMethod.getResponseBodyAsStream();
postMethod.releaseConnection();

它不断回来500.服务提供商说我需要发送JSON。如何使用Apache HttpClient 3.1 +？

完成

Answer 1

Apache HttpClient对JSON一无所知，因此您需要单独构建JSON。为此，我建议您从JSON-java查看简单的json.org库。（如果“JSON-java”不适合你，json.org有很多不同语言的库。）

生成JSON后，您可以使用类似下面的代码来发布它

StringRequestEntity requestEntity = new StringRequestEntity(
    JSON_STRING,
    "application/json",
    "UTF-8");

PostMethod postMethod = new PostMethod("http://example.com/action");
postMethod.setRequestEntity(requestEntity);

int statusCode = httpClient.executeMethod(postMethod);

修改

注 - 上述答案，如问题所述，适用于Apache HttpClient 3.1。但是，为了帮助任何人寻找针对最新Apache客户端的实现：

StringEntity requestEntity = new StringEntity( JSON_STRING, ContentType.APPLICATION_JSON); HttpPost postMethod = new HttpPost("http://example.com/action"); postMethod.setEntity(requestEntity); HttpResponse rawResponse = httpclient.execute(postMethod);

Answer 2

对于 Apache HttpClient 4.5 或更高版本：

@babel/polyfill

注意：

1为了编译代码，应同时导入CloseableHttpClient httpclient = HttpClients.createDefault(); HttpPost httpPost = new HttpPost("http://targethost/login"); String JSON_STRING=""; HttpEntity stringEntity = new StringEntity(JSON_STRING,ContentType.APPLICATION_JSON); httpPost.setEntity(stringEntity); CloseableHttpResponse response2 = httpclient.execute(httpPost);软件包和httpclient软件包。

2个try-catch块已被省略。

参考： appache official guide

Commons HttpClient项目现已终止，并且不再存在正在开发中。它已被Apache HttpComponents取代 HttpClient和HttpCore模块中的项目

Answer 3

正如 janoside 的优秀答案所述，您需要构建JSON字符串并将其设置为StringEntity。

要构造JSON字符串，您可以使用您熟悉的任何库或方法。杰克逊图书馆就是一个简单的例子：

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;

ObjectMapper mapper = new ObjectMapper();
ObjectNode node = mapper.createObjectNode();
node.put("name", "value"); // repeat as needed
String JSON_STRING = node.toString();
postMethod.setEntity(new StringEntity(JSON_STRING, ContentType.APPLICATION_JSON));

如何使用Apache HttpClient发布JSON请求？

3 个答案: