Java如何优雅的调用外部Api

停下脚步才注意到 世界被染得雪白

在日常开发的时候，经常会遇到需要调用别人的接口的场景。但是每次需要的时候，都需要百度，很麻烦，所以这里总结一下，经常调用的方法。
1.含有文件的post请求

public static String requestOCRForHttp(String url, Map<String, String> requestParams, String filePathAndName)
        throws Exception {
    String result = null;
    CloseableHttpClient httpClient = HttpClients.createDefault();
    /** HttpPost */
    HttpPost httpPost = new HttpPost(url);
    MultipartEntity reqEntity = new MultipartEntity(); // 建立多文件实例
    FileBody filebody = new FileBody(new File(filePathAndName));
    reqEntity.addPart("pic", filebody);// upload为请求后台的File upload;
    for (String key : requestParams.keySet()) {
        String value = requestParams.get(key);
        reqEntity.addPart(key, new StringBody(value, Charset.forName("utf-8")));
    }
    httpPost.setEntity(reqEntity); // 设置实体
    /** HttpResponse */
    CloseableHttpResponse httpResponse = httpClient.execute(httpPost);
    try {
        HttpEntity httpEntity = httpResponse.getEntity();
        result = EntityUtils.toString(httpEntity, "utf-8");
        EntityUtils.consume(httpEntity);
    } finally {
        try {
            if (httpResponse != null) {
                httpResponse.close();
            }
        } catch (IOException e) {
            logger.info("## release resouce error ##" + e);
        }
    }
    return result;
}

2.单纯的Json

public static String sendHttpPost(String url, String JSONBody) throws Exception {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(url);
        httpPost.addHeader("Content-Type", "application/json");
        httpPost.setEntity(new StringEntity(JSONBody));
        CloseableHttpResponse response = httpClient.execute(httpPost);
//        System.out.println(response.getStatusLine().getStatusCode() + "\n");
        HttpEntity entity = response.getEntity();
        String responseContent = EntityUtils.toString(entity, "UTF-8"); 
//        System.out.println(responseContent);
        response.close();
        httpClient.close();
        return responseContent;
    }

3.String参数

public static String requestOCRForHttp(String url, Map<String, String> requestParams) throws Exception {
   
        String result = null;
        CloseableHttpClient httpClient = HttpClients.createDefault();
        /** HttpPost */
        HttpPost httpPost = new HttpPost(url);
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        Iterator<Entry<String, String>> it = requestParams.entrySet().iterator();
//        System.out.println(params.toString());
        while (it.hasNext()) {
   
            Entry<String, String> en = it.next();
            String key = en.getKey();
            String value = en.getValue();
            if (value != null) {
   
                params.add(new BasicNameValuePair(key, value));
            }