com.google.cloud.trace.sdk.InstalledAppCredentialProvider.java Source code

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Here is the source code for com.google.cloud.trace.sdk.InstalledAppCredentialProvider.java

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// Copyright 2015 Google Inc. All rights reserved.
//
// 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 com.google.cloud.trace.sdk;

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.store.DataStoreFactory;
import com.google.api.client.util.store.FileDataStoreFactory;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.util.List;
import java.util.Properties;

/**
 * Authorizes using the Installed Application approach. See
 * https://developers.google.com/accounts/docs/OAuth2InstalledApp.
 * 
 * TODO: Handle refreshing via the refresh token. Currently when an access token
 * expires, you just go to the data store and delete the stored credentials.
 */
public class InstalledAppCredentialProvider implements CredentialProvider, CanInitFromProperties {

    /**
     * Directory to store user credentials. Defaults to a location under the home directory of the
     * running user.
     */
    private File dataStoreDir = new File(System.getProperty("user.home"), ".store/cloud-trace-sdk");

    /** Instance of the HTTP transport. */
    private HttpTransport httpTransport;

    /**
     * Global instance of the {@link DataStoreFactory}. The best practice is to make it a single
     * globally shared instance across your application.
     */
    private FileDataStoreFactory dataStoreFactory;

    /**
     * The client secrets file for the installed application.
     */
    private File clientSecretsFile;

    public InstalledAppCredentialProvider() throws GeneralSecurityException, IOException {
        httpTransport = GoogleNetHttpTransport.newTrustedTransport();
        dataStoreFactory = new FileDataStoreFactory(dataStoreDir);
    }

    /**
     * Initializes the installed application credentials parameters from a properties file.
     */
    @Override
    public void initFromProperties(Properties props) {
        String clientSecretsFileName = props.getProperty(getClass().getName() + ".clientSecretsFileName");
        if (clientSecretsFileName != null) {
            this.clientSecretsFile = new File(clientSecretsFileName);
        }
        String dataStoreDirName = props.getProperty(getClass().getName() + ".dataStoreDirName");
        if (clientSecretsFileName != null) {
            this.dataStoreDir = new File(dataStoreDirName);
        }
    }

    public File getDataStoreDir() {
        return dataStoreDir;
    }

    public void setDataStoreDir(File dataStoreDir) {
        this.dataStoreDir = dataStoreDir;
    }

    public File getClientSecretsFile() {
        return clientSecretsFile;
    }

    public void setClientSecretsFile(File clientSecretsFile) {
        this.clientSecretsFile = clientSecretsFile;
    }

    @Override
    public Credential getCredential(List<String> scopes) throws CloudTraceException {
        if (clientSecretsFile == null) {
            throw new IllegalStateException("Client-secrets file is required");
        }

        JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
        GoogleClientSecrets clientSecrets;
        try {
            clientSecrets = GoogleClientSecrets.load(jsonFactory, new FileReader(clientSecretsFile));
            GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(httpTransport, jsonFactory,
                    clientSecrets, scopes).setDataStoreFactory(dataStoreFactory).build();
            return new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
        } catch (IOException e) {
            throw new CloudTraceException("Exception getting oauth2 credential", e);
        }
    }
}