net.ronoaldo.code.appenginetools.RemoteApiHelper.java Source code

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Here is the source code for net.ronoaldo.code.appenginetools.RemoteApiHelper.java

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//
//   Copyright 2012 Ronoaldo JLP
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.
//
package net.ronoaldo.code.appenginetools;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Properties;
import java.util.logging.Logger;

import com.google.appengine.repackaged.org.apache.commons.httpclient.Credentials;
import com.google.appengine.tools.remoteapi.RemoteApiInstaller;
import com.google.appengine.tools.remoteapi.RemoteApiOptions;
import com.google.apphosting.api.ApiProxy;

/**
 * Google AppEngine Remote API helper class.
 * 
 * <p>
 * Just a few helper functionality to load previously stored user credentials
 * from configuration file.
 * 
 * @author Ronoaldo JLP &lt;ronoaldo@ronoaldo.net&gt;
 */
public class RemoteApiHelper {

    private static final Logger logger = Logger.getLogger(RemoteApiHelper.class.getName());

    private URL url;

    private RemoteApiInstaller remoteApi;

    /**
     * Creates a new helper instance to connect with the specified URL.
     * 
     * @param url
     *            the URL to be used to connect with the Google AppEngine Remote
     *            API.
     */
    public RemoteApiHelper(String url) {
        try {
            this.url = new URL(url);
        } catch (MalformedURLException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Start the connection, and perform the {@link ApiProxy} setup for the
     * current {@link Thread}.
     */
    public void connect() {
        logger.info("Connecting with " + url.getHost() + ", port " + url.getPort() + ", path=" + url.getPath());

        RemoteApiOptions options = new RemoteApiOptions().server(//
                url.getHost(), url.getPort()).remoteApiPath(url.getPath());

        Properties credentials = getCredentials();

        // If we have a previous session, reuse it:
        if (credentials.containsKey("host")) {
            options.credentials(//
                    credentials.getProperty("email"), serialize(credentials));
        } else {
            options.credentials(credentials.getProperty("email"), credentials.getProperty("password"));
        }

        remoteApi = new RemoteApiInstaller();
        try {
            remoteApi.install(options);
            storeCredentials(remoteApi.serializeCredentials());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private String serialize(Properties credentials) {
        StringWriter sw = new StringWriter();
        credentials.list(new PrintWriter(sw));
        return sw.toString();
    }

    /**
     * Uninstall the Remote API proxy delegate.
     */
    public void disconnect() {
        try {
            remoteApi.uninstall();
        } catch (Exception e) {
            logger.info("Unable to uninstall Remote API: " + e.getMessage());
        }
    }

    /**
     * Retrieve the user {@link Credentials} to connect with the AppEngine
     * Remote API.
     * 
     * <p>
     * Currently, try to load a file from $HOME/.remoteapi.properties, a
     * {@link Properties} file that is suposed to store the email and password
     * for your Google Account. If this file is not found, ask for user
     * credentials from the command-line.
     * 
     * @return the informed user {@link Credentials}.
     */
    protected Properties getCredentials() {
        Properties p = new Properties();
        File f = FileUtils.atHomeDir(".remoteapi.properties");
        if (f.exists()) {
            try {
                p.load(new FileReader(f));
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } else {
            String email = new String(System.console().readLine("Email: "));
            String password = new String(System.console().readPassword("Password: "));
            p.setProperty("email", email);
            p.setProperty("password", password);
        }
        return p;
    }

    /**
     * Stores the current file credentials.
     * 
     * @param credentials
     *            the credentials to be stored.
     */
    protected void storeCredentials(String credentials) {
        FileUtils.saveFileContents(FileUtils.atHomeDir(".remoteapi.properties"), credentials);
    }
}