ops.http.GsonRestClient.java Source code

Introduction

Here is the source code for ops.http.GsonRestClient.java

Source

/**
*
* Copyright (C) 2011 Anton Gravestam.
*
* This file is part of OPS (Open Publish Subscribe).
*
* OPS (Open Publish Subscribe) is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
    
* OPS (Open Publish Subscribe) is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with OPS (Open Publish Subscribe).  If not, see <http://www.gnu.org/licenses/>.
*/
package ops.http;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Type;
import java.net.URLEncoder;

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import com.google.gson.Gson;

class GsonRestClient {

    protected final Gson gson = new Gson();
    protected final String baseUrl;

    public GsonRestClient(String baseUrl) {
        this.baseUrl = baseUrl;

    }

    protected <D> D executeGet(String url, Type listType, Param... params) {
        try {
            String addParams = "?";
            for (Param param : params) {
                addParams += param.key + "=" + param.value + "&";
            }
            if (addParams.endsWith("&") || addParams.endsWith("?")) {
                addParams = addParams.substring(0, addParams.length() - 1);
            }

            HttpClient client = new DefaultHttpClient();
            HttpGet httpGet = new HttpGet(baseUrl + url + addParams);
            HttpResponse execute = client.execute(httpGet);
            return (D) gson.fromJson(new InputStreamReader(execute.getEntity().getContent()), listType);
        } catch (ClientProtocolException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }

    }

    protected Param param(String key, String value) {
        return new Param(key, value);
    }

    protected class Param {
        String key;
        String value;

        public Param(String key, String value) {
            this.key = key;
            try {
                this.value = URLEncoder.encode(value, "UTF-8");
            } catch (UnsupportedEncodingException e) {
                // Should never happen
                throw new RuntimeException(e.getMessage(), e);
            }
        }

    }

}