HttpUtils工具类和post请求json参数传输

import lombok.extern.slf4j.Slf4j;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.ResponseHandler;
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.StringEntity;
import org.apache.http.impl.client.BasicResponseHandler;
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 java.io.IOException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

@Slf4j
public class HttpUtils {

    private static final String ENCODING = "UTF-8";


    public static String post(String url, Map paramsMap) {
        CloseableHttpClient client = HttpClients.createDefault();
        String responseText = "";
        CloseableHttpResponse response = null;
        try {
            HttpPost method = new HttpPost(url);
            if (paramsMap != null) {
                List paramList = new ArrayList();
                for (Map.Entry param : paramsMap.entrySet()) {
                    NameValuePair pair = new BasicNameValuePair(param.getKey(), param.getValue());
                    paramList.add(pair);
                }
                method.setEntity(new UrlEncodedFormEntity(paramList, ENCODING));
            }
            response = client.execute(method);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                responseText = EntityUtils.toString(entity);
            }
        } catch (Exception e) {
            log.error("http request failed",e);
        } finally {
            try {
                response.close();
            } catch (Exception e) {
                log.error("",e);
            }
        }
        return responseText;
    }

    public static String get(String url, Map paramsMap) {
        CloseableHttpClient client = HttpClients.createDefault();
        String responseText = "";
        CloseableHttpResponse response = null;
        try {
            String getUrl = url+"?";
            if (paramsMap != null) {
                for (Map.Entry param : paramsMap.entrySet()) {
                    getUrl += param.getKey() + "=" + URLEncoder.encode(param.getValue(), ENCODING)+"&";
                }
            }
            HttpGet method = new HttpGet(getUrl);
            response = client.execute(method);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                responseText = EntityUtils.toString(entity);
            }
        } catch (Exception e) {
            log.error("http request failed",e);
        } finally {
            try {
                response.close();
            } catch (Exception e) {
                log.error("",e);
            }
        }
        return responseText;
    }
        //post请求参数为json格式
    public static String HttpPostWithJson(String url, String json) {
        String returnValue = "这是默认返回值，接口调用失败";
        CloseableHttpClient httpClient = HttpClients.createDefault();
        ResponseHandler responseHandler = new BasicResponseHandler();
        try{
            //第一步：创建HttpClient对象
            httpClient = HttpClients.createDefault();

            //第二步：创建httpPost对象
            HttpPost httpPost = new HttpPost(url);

            //第三步：给httpPost设置JSON格式的参数
            StringEntity requestEntity = new StringEntity(json,"utf-8");
            requestEntity.setContentEncoding("UTF-8");
            httpPost.setHeader("Content-type", "application/json");
            httpPost.setEntity(requestEntity);

            //第四步：发送HttpPost请求，获取返回值
            returnValue = httpClient.execute(httpPost,responseHandler); //调接口获取返回值时，必须用此方法

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

        finally {
            try {
                httpClient.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        //第五步：处理返回值
        return returnValue;
    }


}

调用方式都很简单前面两个是url+map

map的key是参数，value是值。无参的话传null就好了

post传入json参数的话注意传入的json要转义。可以在postman上转为json格式进行复制就好了

获取到了json数据，如何json转list并传到数据库的话可以看看我上一篇