JavaのHttpClientのバージョンを上げる時のマイグレーション

HttpClientの３系から４系にする時の変更方法です。

POSTメソッドを使用してパラメータとともにJSONをリクエストとして送っています。

HttpClient 3系

      String myUrl = "http://XXXXXXX";
      HttpClient httpClient = new HttpClient();
      httpClient.getParams().setParameter("http.connection.timeout", 5000);
      httpClient.getParams().setParameter("http.socket.timeout", 3000);
      PostMethod postMethod = new PostMethod(myUrl);
      postMethod.addRequestHeader("Content-Type", "application/javascript");
      postMethod.addParameter("req", "1");
      postMethod.addParameter("callback", "1");
      JSONObject jsonObject = new JSONObject();
      JSONObject context = new JSONObject();
      context.put("country", "JP");
      context.put("language", "ja");
      jsonObject.put("context", context);
      postMethod.setRequestEntity(new StringRequestEntity(
        jsonObject.toString(),
        "application/javascript",
        "UTF-8"));
      httpClient.executeMethod(postMethod);
      String result = postMethod.getResponseBodyAsString();
      JSONObject fromObject = JSONObject.fromObject(result);

これを書き換えると以下のようになります。

HttpClient 4系

      String myUrl = "http://XXXXXXX";
      RequestConfig requestConfig =
        RequestConfig
          .custom()
          .setConnectTimeout(5000)
          .setSocketTimeout(3000)
          .build();
      HttpClient httpClient =
        HttpClientBuilder
          .create()
          .setDefaultRequestConfig(requestConfig)
          .build();
      List<NameValuePair> requestParams = new ArrayList<NameValuePair>();
      requestParams.add(new BasicNameValuePair("req", "1"));
      requestParams.add(new BasicNameValuePair("callback", "1"));
      URIBuilder builder = new URIBuilder(myUrl);
      builder.setParameters(requestParams);
      HttpPost postMethod = new HttpPost(builder.build());
      postMethod.addHeader("Content-Type", "application/javascript");
      JSONObject jsonObject = new JSONObject();
      JSONObject context = new JSONObject();
      context.put("country", "JP");
      context.put("language", "ja");
      jsonObject.put("context", context);
      StringEntity postEntity =
        new StringEntity(jsonObject.toString(), "UTF-8");
      postEntity.setContentType("application/javascript");
      postMethod.setEntity(postEntity);
      HttpResponse response = httpClient.execute(postMethod);
      String result = EntityUtils.toString(response.getEntity());
      JSONObject fromObject = JSONObject.fromObject(result);

参考

パラメータの渡し方の変更方法

http://stackoverflow.com/questions/22038957/httpclient-getparams-deprecated-what-should-i-use-instead

http://stackoverflow.com/questions/12059278/how-to-post-json-request-using-apache-httpclient

レスポンスボディの受け取り方

http://stackoverflow.com/questions/14024625/how-to-get-httpclient-returning-status-code-and-response-body

JSONリクエストをPOSTする方法

http://qiita.com/yukiko-kato-bass/items/092e30bea021286d0348

３系と４系の書き換え方

https://developer.salesforce.com/page/JP:Getting_Started_with_the_Force.com_REST_API

https://developer.salesforce.com/page/JP:DemoREST.java