java实现发送get/post请求并携带参数

前言

package com.example.httpSimulate;

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
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.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.message.BasicHeader;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;
import java.net.URI;
import java.util.*;

/**
 * http请求工具
 */
public class HttpUtil {

//    private static final Logger logger = LoggerFactory.getLogger(HttpUtil.class);

    /**
     * 发送post请求携带json数据
     * @param URL
     * @param json
     * @param headerMap
     * @return
     */
    public static String sendPostJson(String URL, JSONObject json, HashMap headerMap) {
        CloseableHttpClient client = HttpClients.createDefault();
        HttpPost post = new HttpPost(URL);
        Iterator> iterator = headerMap.entrySet().iterator();
        while (iterator.hasNext()) {
            Map.Entry next = iterator.next();
            post.addHeader(next.getKey(),next.getValue());
        }
        String result;
        try {
            StringEntity s = new StringEntity(json.toString(), "utf-8");
            s.setContentType(new BasicHeader(HTTP.CONTENT_TYPE,
                    "application/json"));
            post.setEntity(s);
            // 发送请求
            HttpResponse httpResponse = client.execute(post);
            System.out.println(httpResponse.getEntity().toString());
            // 获取响应输入流
            InputStream inStream = httpResponse.getEntity().getContent();
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    inStream, "utf-8"));
            StringBuilder strber = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null)
                strber.append(line + "\n");
            inStream.close();
            result = strber.toString();
            if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                System.out.println("请求服务器成功，做相应处理");
            } else {
                System.out.println("请求服务端失败");
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return result;
    }

    /**
     * @param url 访问地址
     * @param headerMap  header 参数；可以通过下面工具类将string类型转换成map
     * @param contentMap 需要传输参数参数；对象可以通过json转换成map
     * @return 返回网页返回的数据
     */
    public static String sendPostForm(String url, Map headerMap, Map contentMap) {
        String result = null;
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost post = new HttpPost(url);

        // 设置请求头
//        post.addHeader("Content-Type", "application/x-www-form-urlencoded");

        List content = new ArrayList();
        //将content生成entity
        Iterator iterator = contentMap.entrySet().iterator();
        while (iterator.hasNext()) {
            Map.Entry elem = (Map.Entry) iterator.next();
            content.add(new BasicNameValuePair(elem.getKey(), elem.getValue()));
        }
        CloseableHttpResponse response = null;
        try {
            //循环增加header
            Iterator headerIterator = headerMap.entrySet().iterator();
            while (headerIterator.hasNext()) {
                Map.Entry elem = (Map.Entry) headerIterator.next();
                post.addHeader(elem.getKey(), elem.getValue());
            }
            if (content.size() > 0) {
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(content, "UTF-8");
                post.setEntity(entity);
            }
            //发送请求并接收返回数据
            response = httpClient.execute(post);
            if (response != null && response.getStatusLine().getStatusCode() == 200) {
                //获取response的body部分
                HttpEntity entity = response.getEntity();
                //读取reponse的body部分并转化成字符串
                result = EntityUtils.toString(entity);
            }
            return result;
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                httpClient.close();
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
    /**
     * 发送get请求
     * @param url 请求URL
     * @param param 请求参数 key:value url携带参数 或者无参可不填
     * @return
     */
    public static String doGet(String url, Map param) {

        // 创建Httpclient对象
        CloseableHttpClient httpclient = HttpClients.createDefault();

        String resultString = "";
        CloseableHttpResponse response = null;
        try {
            // 创建uri
            URIBuilder builder = new URIBuilder(url);
            if (param != null) {
                for (String key : param.keySet()) {
                    builder.addParameter(key, param.get(key));
                }
            }
            URI uri = builder.build();

            // 创建http GET请求
            HttpGet httpGet = new HttpGet(uri);

            // 执行请求
            response = httpclient.execute(httpGet);
            // 判断返回状态是否为200
            if (response.getStatusLine().getStatusCode() == 200) {
                resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (response != null) {
                    response.close();
                }
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return resultString;
    }

}