java实现Get、Post请求接口获取json数据

1. HttpClient实现get、post请求

import com.alibaba.fastjson.JSON;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
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.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
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 org.json.JSONObject;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
@Component
public class HttpClientUtils {
    /**
     * 有参数请求的get请求
     * @param url 请求接口
     * @param paramMap 请求参数Map对象
     * @return
     */
    public static JSONObject getParamMap(String url, Map<String, String> paramMap) {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        try {
            List<NameValuePair> pairs = new ArrayList<>();
            for(Map.Entry<String,String> entry:paramMap.entrySet()){
                pairs.add(new BasicNameValuePair(entry.getKey(),entry.getValue()));
            }
            CloseableHttpResponse response;
            URIBuilder builder = new URIBuilder(url).setParameters(pairs);
            // 执行get请求.
            HttpGet httpGet = new HttpGet(builder.build());
            response = httpClient.execute(httpGet);
            if(response != null && response.getStatusLine().getStatusCode() == 200) {
                HttpEntity entity = response.getEntity();
                String jsonString= EntityUtils.toString(entity);
                JSONObject jsonObject=new JSONObject(jsonString);
//                System.out.println("get请求数据成功！\n"+jsonObject);
                return jsonObject;
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 关闭连接,释放资源
            try {
                httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }


    /**
     * 发送post请求，参数用map接收
     * @param url 地址
     * @param object 请求的对象
     * @return 返回值
     */

    public static JSONObject postMap(String url,Object object) {
        //获取json字符串
        String json= JSON.toJSONString(object);
        System.out.println(json);
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(url);
        CloseableHttpResponse response;
        try {
            StringEntity stringEntity=new StringEntity(json, ContentType.APPLICATION_JSON);
            httpPost.setEntity(stringEntity);
            response = httpClient.execute(httpPost);
            if (response != null && response.getStatusLine().getStatusCode() == 200) {
                HttpEntity entity = response.getEntity();
                String jsonString= EntityUtils.toString(entity);
                JSONObject jsonObject=new JSONObject(jsonString);
                return jsonObject;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 关闭连接,释放资源
            try {
                httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
}