java代码调用第三方接口

一、利用httpclient来字符串参数（url是第三方接口，不带参数，如:http://192.168.16.200:8081/faceInfo/list，param是url后面所要带的参数）

public static JSONObject getHttpResponseJson(String url,Map<String,String> param){
        CloseableHttpClient httpclient = null;
        CloseableHttpResponse response = null;
        JSONObject jsonObject = null;

        try {
            //请求发起客户端
            httpclient = HttpClients.createDefault();
            //参数集合
            List postParams = new ArrayList();
            //遍历参数并添加到集合
            for(Map.Entry<String, String> entry:param.entrySet()){
                postParams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
            }
            //通过post方式访问
            HttpPost post = new HttpPost(url);
            HttpEntity paramEntity = new UrlEncodedFormEntity(postParams,"UTF-8");
            post.setEntity(paramEntity);
            response = httpclient.execute(post);
            HttpEntity valueEntity = response.getEntity();
            String content = EntityUtils.toString(valueEntity);
            jsonObject = JSONObject.fromObject(content);

            return jsonObject;
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            if(httpclient != null){
                try {
                    httpclient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(response != null){
                try {
                    response.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return jsonObject;
    }

二、利用httpclient来同时上传文件和其他字符串参数(postUrl请求地址，第三方接口，不带参数，如:http://192.168.16.200:8081/faceInfo/list，filePathParam封装文件的上传路径，param封装参数)

public static String getHttpResponseString(String postUrl,Map<String,String> filePathParam,Map<String,String> param){
        //1:创建一个httpclient对象
        HttpClient httpclient = new DefaultHttpClient();
        Charset charset = Charset.forName("UTF-8");//设置编码
        try {
            //2：创建http的发送方式对象，是GET还是post
            HttpPost httppost = new HttpPost(postUrl);

            //3：创建要发送的实体，就是key-value的这种结构，借助于这个类，可以实现文件和参数同时上传
            MultipartEntity reqEntity = new MultipartEntity();

            if (filePathParam != null) {
                //遍历图片并添加到MultipartEntity实体中
                for(Map.Entry<String, String> entry:filePathParam.entrySet()){
                     FileBody fileContent = new FileBody(new File(entry.getValue()));
                     reqEntity.addPart(entry.getKey(),fileContent);
                }
            }

            if (param != null) {
                //遍历参数并添加到MultipartEntity实体中
                for(Map.Entry<String, String> entry:param.entrySet()){
                    StringBody content = new StringBody(entry.getValue(),charset);
                    reqEntity.addPart(entry.getKey(), content);
                }
            }

            httppost.setEntity(reqEntity);

            //4：执行httppost对象，从而获得信息
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity resEntity = response.getEntity();

            //获得返回来的信息，转化为字符串string
            String resString = EntityUtils.toString(resEntity);
            return resString;

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try { httpclient.getConnectionManager().shutdown(); } catch (Exception ignore) {}
        }
        return null;
    }