java调用第三方接口代码，返回json/xml数据并可以输出到页面（含pom）

红太狼 2022-04-23 13:26 288阅读 0赞

**pom文件**

<dependency>
          <groupId>org.apache.httpcomponents</groupId>
          <artifactId>httpclient</artifactId>
          <version>4.5.2</version>
        </dependency>
    
        <dependency>
          <groupId>org.apache.httpcomponents</groupId>
          <artifactId>httpclient-cache</artifactId>
          <version>4.5</version>
        </dependency>
    
        <dependency>
          <groupId>org.apache.httpcomponents</groupId>
          <artifactId>httpmime</artifactId>
          <version>4.3.2</version>
        </dependency>

**一、使用get方式调用（返回json）**

protected void service(HttpServletRequest request, HttpServletResponse response){
    	         response.setCharacterEncoding("utf-8");
    	         response.setContentType("application/json; charset=utf-8");
    	         String urlStr= "第三方url接口";
    	         String jsonString = null;
                 try {
    		            URL url = new URL(urlStr);
    		            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    		            conn.setRequestMethod("GET");
    		            conn.connect();
    		            BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));
    		            String line = "";
    		            StringBuffer buffer = new StringBuffer();
    		            while ((line = reader.readLine() )!= null){
    		                buffer.append(line);
    		            }
    		            reader.close();
    		            conn.disconnect();
    		             jsonString = buffer.toString();
    	        } catch (Exception e) {
    	            e.printStackTrace();
    	        }
             PrintWriter printWriter = null;
             try {
                 printWriter = response.getWriter();
             } catch (IOException e) {
                 e.printStackTrace();
             }
             printWriter.print(jsonString );
        }

**二、使用post方式调用**

//以后更新

**三、第三方返回的是一个xml文件（get方式）**

protected void service(HttpServletRequest request, HttpServletResponse response){
        response.setCharacterEncoding("utf-8");
        String urlStr = "第三方url接口";
        String result = getInfoByHttp(urlStr);
        PrintWriter printWriter = null;
        try {
            printWriter = response.getWriter();
        } catch (IOException e) {
            e.printStackTrace();
        }
        printWriter.print(result);
    }
        public static String getInfoByHttp(String url) {
            HttpGet httpGet = new HttpGet(url);
            HttpClient httpClient = new DefaultHttpClient();
            String result = "";
            try {
                HttpResponse httpResponse = httpClient.execute(httpGet);
                result = getJsonStringFromGZIP(httpResponse);
                return result;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
        private static String getJsonStringFromGZIP(HttpResponse response) {
            String jsonString = null;
            try {
                InputStream is = response.getEntity().getContent();
                BufferedInputStream bis = new BufferedInputStream(is);
                bis.mark(2);
                // 取前两个字节
                byte[] header = new byte[2];
                int result = bis.read(header);
                // reset输入流到开始位置
                bis.reset();
                // 判断是否是GZIP格式
                int headerData = getShort(header);
                if (result != -1 && headerData == 0x1f8b) {
                    is = new GZIPInputStream(bis);
                } else {
                    is = bis;
                }
                InputStreamReader reader = new InputStreamReader(is, "utf-8");
                char[] data = new char[100];
                int readSize;
                StringBuffer sb = new StringBuffer();
                while ((readSize = reader.read(data)) > 0) {
                    sb.append(data, 0, readSize);
                }
                jsonString = sb.toString();
                bis.close();
                reader.close();
            } catch (Exception e) {
            }
            return jsonString;
        }
        private static int getShort(byte[] data) {
            return (int) ((data[0] << 8) | data[1] & 0xFF);
        }