Add operation to get users from the server

/* ownCloud Android Library is available under MIT license

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package com.owncloud.android.lib.resources.users;

import com.owncloud.android.lib.common.OwnCloudClient;

import com.owncloud.android.lib.common.operations.RemoteOperation;

import com.owncloud.android.lib.common.operations.RemoteOperationResult;

import com.owncloud.android.lib.common.utils.Log_OC;

import org.apache.commons.httpclient.NameValuePair;

import org.apache.commons.httpclient.methods.GetMethod;

import org.apache.http.HttpStatus;

import org.json.JSONArray;

import org.json.JSONObject;

import java.util.ArrayList;

/**

 * Created by masensio on 08/10/2015.

 *

 * Retrieves a list of users from the ownCloud server. Authentication is done by sending a Basic HTTP Authorization header.

 * Syntax: ocs/v1.php/cloud/users

 *    HTTP method: GET

 *    url arguments: search - string, optional search string

 *    url arguments: limit - int, optional limit value

 *    url arguments: offset - int, optional offset value

 *

 * Status codes:

 *    100 - successful

 */

public class GetRemoteUsersOperation extends RemoteOperation{

    private static final String TAG = GetRemoteUserNameOperation.class.getSimpleName();

    // OCS Route

    private static final String OCS_ROUTE ="/ocs/v1.php/cloud/users?format=json";

    // Arguments

    private static final String PARAM_SEARCH = "search";

    private static final String PARAM_LIMIT = "limit";

    private static final String PARAM_OFFSET = "offset";

    // JSON Node names

    private static final String NODE_OCS = "ocs";

    private static final String NODE_META = "meta";

    private static final String NODE_STATUS = "status";

    private static final String NODE_STATUSCODE = "statuscode";

    private static final String NODE_MESSAGE = "message";

    private static final String NODE_DATA = "data";

    private static final String NODE_USERS = "users";

    private ArrayList<String> mUsers;  // List of users

    private String mSearchString;

    private int mLimit;

    private int mOffset;

    /**

     * Constructor

     *

     * @param searchString  	string for searching users, optional

     * @param limit 			limit, optional

     * @param offset			offset, optional

     */

    public GetRemoteUsersOperation(String searchString, int limit, int offset) {

        mSearchString = searchString;

        mLimit = limit;

        mOffset = offset;

    }

    @Override

    protected RemoteOperationResult run(OwnCloudClient client) {

        RemoteOperationResult result = null;

        int status = -1;

        GetMethod get = null;

        try{

            // Get Method

            get = new GetMethod(client.getBaseUri() + OCS_ROUTE);

            // Add Parameters to Get Method

            get.setQueryString(new NameValuePair[]{

                    new NameValuePair(PARAM_SEARCH, mSearchString),

                    new NameValuePair(PARAM_LIMIT, String.valueOf(mLimit)),

                    new NameValuePair(PARAM_OFFSET, String.valueOf(mOffset))

            });

            //¿?

            get.addRequestHeader(OCS_API_HEADER, OCS_API_HEADER_VALUE);

            status = client.executeMethod(get);

            if(isSuccess(status)) {

                String response = get.getResponseBodyAsString();

                Log_OC.d(TAG, "Successful response: " + response);

                // Parse the response

                JSONObject respJSON = new JSONObject(response);

                JSONObject respOCS = respJSON.getJSONObject(NODE_OCS);

                JSONObject respData = respOCS.getJSONObject(NODE_DATA);

                JSONArray  respUsers = respData.getJSONArray(NODE_USERS);

                mUsers = new ArrayList<String>();

                ArrayList<Object> data = new ArrayList<Object>(); // For result data

                for(int i=0; i<= respUsers.length(); i++){

                    JSONObject jsonUser = respUsers.getJSONObject(i);

                    String user = jsonUser.toString();

                    mUsers.add(user);

                    data.add(user);

                    Log_OC.d(TAG, "*** USER : " + user);

                }

                // Result

                result = new RemoteOperationResult(true, status, get.getResponseHeaders());

                result.setData(data);

                Log_OC.d(TAG, "*** Get Users completed " );

            } else {

                result = new RemoteOperationResult(false, status, get.getResponseHeaders());

                String response = get.getResponseBodyAsString();

                Log_OC.e(TAG, "Failed response while getting users from the server ");

                if (response != null) {

                    Log_OC.e(TAG, "*** status code: " + status + "; response message: " + response);

                } else {

                    Log_OC.e(TAG, "*** status code: " + status);

                }

            }

        } catch (Exception e) {

            result = new RemoteOperationResult(e);

            Log_OC.e(TAG, "Exception while getting users", e);

        } finally {

            if (get != null) {

                get.releaseConnection();

            }

        }

        return result;

    }

    private boolean isSuccess(int status) {

        return (status == HttpStatus.SC_OK);

    }

}