(Java) 模擬http請求調用遠程接口

 

package com.vcgeek.hephaestus.utils;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 功能描述
 *
 * @author: zyu
 * @description:
 * @date: 2019/3/22 11:10
 */
public class HttpClientUtil {

    /**
     * 發送GET請求
     *
     * @param url        目的地址
     * @param parameters 請求參數，Map類型。
     * @return 遠程響應結果
     */
    public static String sendGet(String url, Map<String, String> parameters) {
        String result = "";
        BufferedReader in = null;// 讀取響應輸入流
        StringBuffer sb = new StringBuffer();// 存儲參數
        String params = "";// 編碼之后的參數
        try {
            // 編碼請求參數
            if (parameters.size() == 1) {
                for (String name : parameters.keySet()) {
                    sb.append(name).append("=").append(
                            java.net.URLEncoder.encode(parameters.get(name),
                                    "UTF-8"));
                }
                params = sb.toString();
            } else {
                for (String name : parameters.keySet()) {
                    sb.append(name).append("=").append(
                            java.net.URLEncoder.encode(parameters.get(name),
                                    "UTF-8")).append("&");
                }
                String temp_params = sb.toString();
                params = temp_params.substring(0, temp_params.length() - 1);
            }
            String full_url = url + "?" + params;
            System.out.println(full_url);
            // 創建URL對象
            java.net.URL connURL = new java.net.URL(full_url);
            // 打開URL連接
            java.net.HttpURLConnection httpConn = (java.net.HttpURLConnection) connURL
                    .openConnection();
            // 設置通用屬性
            httpConn.setRequestProperty("Accept", "*/*");
            httpConn.setRequestProperty("Connection", "Keep-Alive");
            httpConn.setRequestProperty("User-Agent",
                    "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1)");
            // 建立實際的連接
            httpConn.connect();
            // 響應頭部獲取
            Map<String, List<String>> headers = httpConn.getHeaderFields();
            // 遍歷所有的響應頭字段
            for (String key : headers.keySet()) {
                System.out.println(key + "\t：\t" + headers.get(key));
            }
            // 定義BufferedReader輸入流來讀取URL的響應,並設置編碼方式
            in = new BufferedReader(new InputStreamReader(httpConn
                    .getInputStream(), "UTF-8"));
            String line;
            // 讀取返回的內容
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result;
    }

    /**
     * 發送POST請求
     *
     * @param url        目的地址
     * @param parameters 請求參數，Map類型。
     * @return 遠程響應結果
     */
    public static String sendPost(String url, Map<String, String> parameters) {
        String result = "";// 返回的結果
        BufferedReader in = null;// 讀取響應輸入流
        PrintWriter out = null;
        StringBuffer sb = new StringBuffer();// 處理請求參數
        String params = "";// 編碼之后的參數
        try {
            // 編碼請求參數
            if (parameters.size() == 1) {
                for (String name : parameters.keySet()) {
                    sb.append(name).append("=").append(
                            java.net.URLEncoder.encode(parameters.get(name),
                                    "UTF-8"));
                }
                params = sb.toString();
            } else {
                for (String name : parameters.keySet()) {
                    sb.append(name).append("=").append(
                            java.net.URLEncoder.encode(parameters.get(name),
                                    "UTF-8")).append("&");
                }
                String temp_params = sb.toString();
                params = temp_params.substring(0, temp_params.length() - 1);
            }
            // 創建URL對象
            java.net.URL connURL = new java.net.URL(url);
            // 打開URL連接
            java.net.HttpURLConnection httpConn = (java.net.HttpURLConnection) connURL
                    .openConnection();
            // 設置通用屬性
            httpConn.setRequestProperty("Accept", "*/*");
            httpConn.setRequestProperty("Connection", "Keep-Alive");
            httpConn.setRequestProperty("User-Agent",
                    "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1)");
            // 設置POST方式
            httpConn.setDoInput(true);
            httpConn.setDoOutput(true);
            // 獲取HttpURLConnection對象對應的輸出流
            out = new PrintWriter(httpConn.getOutputStream());
            // 發送請求參數
            out.write(params);
            // flush輸出流的緩沖
            out.flush();
            // 定義BufferedReader輸入流來讀取URL的響應，設置編碼方式
            in = new BufferedReader(new InputStreamReader(httpConn
                    .getInputStream(), "UTF-8"));
            String line;
            // 讀取返回的內容
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result;
    }

}