POST工具类

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.BasicHttpEntity;
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 java.util.*;

public class PostUtil {
    private static final String CHARSET = "UTF-8";
    public static String post(String url, String params) {
        try {
            CloseableHttpClient httpClient = HttpClients.createDefault();
            HttpPost httpPost = new HttpPost(url);
            StringEntity sEntity = new StringEntity(params, CHARSET);
            httpPost.setEntity(sEntity);
            CloseableHttpResponse response = httpClient.execute(httpPost);
            try {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    return EntityUtils.toString(entity, CHARSET);
                }
            } finally {
                response.close();
                httpClient.close();
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return null;
    }
    public static String postObject(String url, Map<String,Object> parammap) {

        CloseableHttpClient httpclient = HttpClients.createDefault();
        // 创建httppost
        HttpPost httppost = new HttpPost(url);
        // 创建参数队列
        List<NameValuePair> formparams = new ArrayList<NameValuePair>();
        for (Map.Entry<String, Object> entry : parammap.entrySet()) {
            formparams.add(new BasicNameValuePair(entry.getKey(), entry.getValue().toString()));
        }
        UrlEncodedFormEntity uefEntity;
        try {
            uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
            httppost.setEntity(uefEntity);
            CloseableHttpResponse response = httpclient.execute(httppost);
            try {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    // 调用接口返回的字符串
                    return EntityUtils.toString(entity, "UTF-8");

                }
            } finally {
                response.close();
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return null;
    }


    public static String postJson(String url, String json){
        return postJSONWithHeaders(url, json, null);
    }

    public static String postJSONWithHeaders(String url, String json, Map<String, String> headers) {
        try {
            CloseableHttpClient httpClient = HttpClients.createDefault();
            HttpPost httpPost = new HttpPost(url);
            StringEntity sEntity = new StringEntity(json, CHARSET);
            httpPost.setEntity(sEntity);
            httpPost.setHeader("Content-Type","application/json;charset=utf-8");
            if (headers != null) {
                for (String key : headers.keySet()) {
                    httpPost.setHeader(key, headers.get(key));
                }
            }
            CloseableHttpResponse response = httpClient.execute(httpPost);
            try {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    return EntityUtils.toString(entity, CHARSET);
                }
            } finally {
                response.close();
                httpClient.close();
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return null;
    }

    public static String post(String url, Map<String,String> params) {
        return postForm(url, params, null);
    }

    public static String postForm(String url, Map<String, String> params, String contentType) {
        try {
            CloseableHttpClient httpClient = HttpClients.createDefault();
            HttpPost httpPost = new HttpPost(url);
            if (contentType != null) {
                httpPost.setHeader("Content-Type",contentType);
            }
            List<NameValuePair> nameValuePairs = new LinkedList<>();
            for (String key : params.keySet()) {
                nameValuePairs.add(new BasicNameValuePair(key, params.get(key)));
            }
            UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(nameValuePairs,CHARSET);
            httpPost.setEntity(urlEncodedFormEntity);
            CloseableHttpResponse response = httpClient.execute(httpPost);
            try {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    return EntityUtils.toString(entity, CHARSET);
                }
            } finally {
                response.close();
                httpClient.close();
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return null;
    }

    public static String postFormData(String url, Map<String, String> params) {
        try {
            CloseableHttpClient httpClient = HttpClients.createDefault();
            HttpPost httpPost = new HttpPost(url);
            httpPost.setHeader("Content-Type","application/form-data");
            List<NameValuePair> nameValuePairs = new LinkedList<>();
            for (String key : params.keySet()) {
                nameValuePairs.add(new BasicNameValuePair(key, params.get(key)));
            }
            UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(nameValuePairs,CHARSET);
            httpPost.setEntity(urlEncodedFormEntity);
            CloseableHttpResponse response = httpClient.execute(httpPost);
            try {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    return EntityUtils.toString(entity, CHARSET);
                }
            } finally {
                response.close();
                httpClient.close();
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return null;
    }
}