import org.apache.commons.lang3.StringUtils;
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.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
 
import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.net.URI;
import java.nio.charset.Charset;
 
/**
 * @author YoonaLt
 */
public class HttpUtils {
    /**
     * 发送 get 请求
     *
     * @param url 请求地址
     * @return 请求结果
     */
    public static String get(String url) {
        String result = null;
        CloseableHttpResponse response = null;
        CloseableHttpClient httpclient = HttpClients.createDefault();
        try {
            // 创建uri
            URIBuilder builder = new URIBuilder(url);
            URI uri = builder.build();
            // 创建http GET请求
            HttpGet httpGet = new HttpGet(uri);
            // 执行请求
            response = httpclient.execute(httpGet);
            if (response.getStatusLine().getStatusCode() == 200) {
                result = EntityUtils.toString(response.getEntity(), "UTF-8");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
 
    /**
     * 发送 post 请求
     *
     * @param url     请求地址
     * @param jsonStr Form表单json字符串
     * @return 请求结果
     */
    public static String post(String url, String jsonStr) {
        // 创建httpClient
        CloseableHttpClient httpClient = HttpClients.createDefault();
        // 创建post请求方式实例
        HttpPost httpPost = new HttpPost(url);
 
        // 设置请求头 发送的是json数据格式
        httpPost.setHeader("Content-type", "application/json;charset=utf-8");
        httpPost.setHeader("Connection", "Close");
 
        // 设置参数---设置消息实体 也就是携带的数据
        StringEntity entity = new StringEntity(jsonStr, Charset.forName("UTF-8"));
        // 设置编码格式
        entity.setContentEncoding("UTF-8");
        // 发送Json格式的数据请求
        entity.setContentType("application/json");
        // 把请求消息实体塞进去
        httpPost.setEntity(entity);
 
        // 执行http的post请求
        CloseableHttpResponse httpResponse;
        String result = null;
        try {
            httpResponse = httpClient.execute(httpPost);
            result = EntityUtils.toString(httpResponse.getEntity(), "UTF-8");
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        return result;
    }
 
    /**
     * 获取请求ip地址
     */
    public static String getRequestIp(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)) {
            //多次反向代理后会有多个ip值，第一个ip才是真实ip
            int index = ip.indexOf(",");
            if (index != -1) {
                return ip.substring(0, index);
            } else {
                return ip;
            }
        }
        ip = request.getHeader("X-Real-IP");
        if (StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)) {
            return ip;
        }
        return request.getRemoteAddr();
    }
}