java 调用第三方系统时的连接代码-记录

前言：该文章主要是总结我在实际工作中遇到的问题，在调取第三方系统的时候出现的问题，算自己的总结。各位博友如果有什么建议或意见欢迎留言指正。

1. 先将准备传入参数
2. 再与第三方系统建立连接
3. 再第三方系统处理后给你返回需要的信息

调用第三方的系统的url(restful风格) 
http://Ip地址:端口号/casereview/api/addTCaseReview

在业务逻辑实现类中通过工具类调用第三方接口。 
String postParam = “”; //传入参数 
String url = “”; //第三方接口url 
long timeOut = 20000; //超时时间 
JSONObject response = CaseEvaluationUtil.sendPost(postParam, url, timeOut ); 
//可以通过读取配置文件获取第三方接口地址 
private static final String EVALUATION_IP = (String) ConcurrentCache.getFieldValue(“evaluationIp”);

通过工具类进行与第三方接口连接交互。 

输出的参数 
 
下面代码中设置请求头的信息来源于Request Headers

/**
     * @description 向合议庭评议系统发送post请求
     * @author junbao
     * @create 2017年11月13日下午3:22:56
     * @version 1.0
     * @param postParam
     * @param url
     * @return String
     * @throws BusinessErrorException
     */
    public static JSONObject sendPost(String postParam, String url, int timeout) throws BusinessErrorException {
        JSONObject result = new JSONObject();
        PrintWriter out = null;
        BufferedReader in = null;
        try {
            if (StringUtils.isBlank(EVALUATION_IP)) {
                throw new BusinessErrorException(CommonConstants.FAILURE, "EVALUATION_IP 不能为空");    
            }
            String targetURL = "http://" + EVALUATION_IP  + url;
            URL resetServiceURL = new URL(targetURL);
            //打开url连接
            HttpURLConnection httpConnection = (HttpURLConnection) resetServiceURL.openConnection();
            //设置连接请求头信息属性       
            httpConnection.setRequestProperty("Accept", "application/json, text/javascript, */*; q=0.01");
            httpConnection.setRequestProperty("Accept-Encoding", "gzip, deflate");
            httpConnection.setRequestProperty("Accept-Language", "zh-CN,zh;q=0.9");
            httpConnection.setRequestProperty("Connection", "keep-alive");
            httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
            httpConnection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36");
            httpConnection.setRequestProperty("X-Requested-With", "XMLHttpRequest");
            //设置超时时间
            httpConnection.setConnectTimeout(timeout);
            httpConnection.setReadTimeout(timeout);
            //设置请求方式
            httpConnection.setRequestMethod("POST");
            httpConnection.setDoInput(true);
            httpConnection.setDoOutput(true);
            //POST请求不应该使用cache
            httpConnection.setUseCaches(false);
            //获取url连接
            httpConnection.connect();
            //获取UrlConnection对象的输出流，调用httpConnection.getOutputStream的时候就会设置为POST方法
            out = new PrintWriter(new OutputStreamWriter(httpConnection.getOutputStream(),"UTF-8"));
            out.write(postParam);
            //flush输出流的缓冲，将参数发送出去
            out.flush();
            //表示连接异常
            if (httpConnection.getResponseCode() != 200) {
                result.put("message", "数据获取异常，请联系系统管理员");
                result.put("result", "ERROR");
                result.put("code", null);
                result.put("object", null);
                return result;
            }
            //读取流中的内容
            in = new BufferedReader(new InputStreamReader(httpConnection.getInputStream(), "UTF-8"));
            String line = "";
            StringBuffer bf = new StringBuffer();
            while (null !=(line = in.readLine())) {
                bf.append(line);
            }

            if (StringUtils.isNoneBlank(bf.toString())) {
                JSONObject evalutionResult = JSONObject.parseObject(bf.toString());
                return evalutionResult;
            }
        } catch (Exception e) {
            logger.error("Send post Exection!",e);
            result.put("message", "数据获取异常，请联系系统管理员");
            result.put("result", "ERROR");
            result.put("code", null);
            result.put("object", null);
            return result;
        } finally {
            // 关闭流
            try {
                if (null != out) {
                    out.close();
                }
                if (null != in) {
                    in.close();
                }
            } catch (Exception e) {
                logger.info("Send post Exection!");
                e.printStackTrace();
                result.put("message", "数据获取异常，请联系系统管理员");
                result.put("result", "ERROR");
                result.put("code", null);
                result.put("object", null);
                return result;
            }
        }
        return result;
    }