JAVA HTTP请求

GET请求方式

   /**
     * Description: 发送GET请求，请求参数为MAP
     * @author: willem
     * @date: 2020/7/13 11:45
     * @param url
     * @param param
     * @return:java.lang.String
     */
    public static String sendGet(String url, Map<String, String> param) {
        // 创建Httpclient对象 
        CloseableHttpClient httpclient = HttpClients.createDefault();
        //设置请求超时时间（各项超时参数具体含义链接）
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(10000)
                .setConnectionRequestTimeout(10000)
                .setSocketTimeout(10000)
                .build();
        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);

            //给这个请求设置请求配置
            httpGet.setConfig(requestConfig);
            httpGet.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; rv:6.0.2) Gecko/20100101 Firefox/6.0.2");

            // 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;
    }

   /**
     * Description: 发送GET请求，请求参数为键值对
     * @author: willem
     * @date: 2020/7/13 11:45
     * @param url
     * @param param
     * @return:java.lang.String
     */
    public static String sendGet(String url, String param) {  
        String result = "";  
        BufferedReader in = null;  
        try {  
            String urlName = param != null && param != "" ?  url + "?" + param : url;
            URL realUrl = new URL(urlName);  
            // 打开和URL之间的连接  
            URLConnection conn = realUrl.openConnection();  
            // 设置通用的请求属性  
            conn.setRequestProperty("accept", "*/*");  
            conn.setRequestProperty("connection", "Keep-Alive");  
            conn.setRequestProperty("user-agent",  
                    "Mozilla/5.0 (Windows NT 6.1; rv:6.0.2) Gecko/20100101 Firefox/6.0.2");  
            // 建立实际的连接  
            conn.connect();  
            // 获取所有响应头字段  
            Map<String, List<String>> map = conn.getHeaderFields();  
            // 遍历所有的响应头字段  
            for (String key : map.keySet()) {  
                System.out.println(key + "--->" + map.get(key));  
            }  
            // 定义BufferedReader输入流来读取URL的响应  
            in = new BufferedReader(  
                    new InputStreamReader(conn.getInputStream()));  
            String line;  
            while ((line = in.readLine()) != null) {  
                result += "/n" + line;  
            }  
        } catch (Exception e) {  
            System.out.println("发送GET请求出现异常！" + e);  
            e.printStackTrace();  
        }  
        // 使用finally块来关闭输入流  
        finally {  
            try {  
                if (in != null) {  
                    in.close();  
                }  
            } catch (IOException ex) {  
                ex.printStackTrace();  
            }  
        }  
        return result;  
    }

POST请求方式

  /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url
     *            发送请求的 URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @param isproxy
     *               是否使用代理模式
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, String param, boolean isproxy) {
        OutputStreamWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            HttpURLConnection conn = null;
            if(isproxy){//使用代理模式
                @SuppressWarnings("static-access")
                Proxy proxy = new Proxy(Proxy.Type.DIRECT.HTTP, new InetSocketAddress(proxyHost, proxyPort));
                conn = (HttpURLConnection) realUrl.openConnection(proxy);
            }else{
                conn = (HttpURLConnection) realUrl.openConnection();
            }
            // 打开和URL之间的连接

            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setRequestMethod("POST");    // POST方法


            // 设置通用的请求属性

            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            conn.connect();

            // 获取URLConnection对象对应的输出流
            out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");
            // 发送请求参数
            out.write(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    }

/**
     * Description: 发送POST请求，参数为MAP
     * @author: willem
     * @date: 2020/7/13 12:21
     * @param url  路径
     * @param param  参数
     * @return:java.lang.String
     */
    public static String sendPost(String url, Map<String, String> param) {
        // 创建Httpclient对象 
        CloseableHttpClient httpClient =  HttpClients.createDefault();
        //设置请求超时时间（各项超时参数具体含义链接）
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(10000)
                .setConnectionRequestTimeout(10000)
                .setSocketTimeout(10000)
                .build();
        String resultString = "";
        CloseableHttpResponse response = null;
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            httpPost.setConfig(requestConfig);
            // 创建参数列表
            if (param != null) {
                List<NameValuePair> paramList = new ArrayList<>();
                for (String key : param.keySet()) {
                    paramList.add(new BasicNameValuePair(key, param.get(key)));
                }

                // 模拟表单
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);
                httpPost.setEntity(entity);
            }

            // 执行http请求
            response = httpClient.execute(httpPost);
            if(response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
                resultString = EntityUtils.toString(response.getEntity(), "utf-8");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return resultString;
    }

/**
     * Description:发送POST请求，参数为JSON
     * @author: willem
     * @date: 2020/7/13 12:26
     * @param url 路径
     * @param params  参数
     * @return:java.lang.String
     */
    public static String sendPostJson(String url, String params) {
        // 创建Httpclient对象 
        CloseableHttpClient httpClient = getHttpClient();
        //设置请求超时时间（各项超时参数具体含义链接）
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(10000)
                .setConnectionRequestTimeout(10000)
                .setSocketTimeout(10000)
                .build();
        String resultString = "";
        CloseableHttpResponse response = null;
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            httpPost.setConfig(requestConfig);
            // 创建请求内容 ，发送json数据需要设置contentType
            StringEntity entity = new StringEntity(params, ContentType.APPLICATION_JSON);
            httpPost.setEntity(entity);


            // 执行http请求
            response = httpClient.execute(httpPost);
            if(response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
                resultString = EntityUtils.toString(response.getEntity(), "utf-8");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return resultString;
    }