Java -- HttpClient之带参Post请求

使用的jar包

• httpcore-4.4.4.jar
• httpclient-4.5.2.jar
• fastjson-1.2.7.jar

说明

• post方法的参数通过HttpPost的setEntity方法设置。服务器端可以通过request.getParameter(“xxx”)接收参数。
• post方法返回值为JSON对象，其中“status_code”为http状态码，“data”为请求返回的数据。
• 示例中，使用FastJson(阿里)解析JSON对象。

示例代码

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
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.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import com.alibaba.fastjson.JSONObject;

public class HttpClient {
  public static JSONObject post(String url, JSONObject jsonData) {
        JSONObject result = new JSONObject();
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        try {
            HttpPost httpPost = new HttpPost(url);
            httpPost.addHeader("Content-type", "application/x-www-form-urlencoded");

            if (jsonData != null && !jsonData.isEmpty()){
                List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
                Set<Entry<String, Object>> set = jsonData.entrySet();
                for (Entry<String, Object> entry : set){
                    String key = entry.getKey();
                    String value = entry.getValue().toString();
                    nameValuePairs.add(new BasicNameValuePair(key, value));
                }
                httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs, "UTF-8"));
            }

            response = httpClient.execute(httpPost);
            HttpEntity entity = response.getEntity();
            int statusCode = response.getStatusLine().getStatusCode();
            result.put("status_code", statusCode);
            if (entity != null) {
                result.put("data", EntityUtils.toString(entity));
            }
        } catch (ClientProtocolException e) {
            Log.logger.error("连接" + url + "失败，原因为" + e.getMessage());
        } catch (ParseException e) {
            Log.logger.error("连接" + url + "失败，原因为" + e.getMessage());
        } catch (IOException e) {
            Log.logger.error("连接" + url + "失败，原因为" + e.getMessage());
        } finally {
            if (response != null){
                try {
                    response.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if (httpClient != null){
                try {
                    httpClient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return result;
    }
}