org.apache.lens.client.LensClientSingletonWrapper.java Source code

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Here is the source code for org.apache.lens.client.LensClientSingletonWrapper.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.lens.client;

import org.apache.lens.client.exceptions.LensClientServerConnectionException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * The Enum LensClientSingletonWrapper.
 */
public enum LensClientSingletonWrapper {

    /** The instance. */
    INSTANCE;

    /** The log. */
    private static final Log LOG = LogFactory.getLog(LensClientSingletonWrapper.class);

    /** The client. */
    private LensClient client;

    /** The Constant MAX_RETRIES. */
    private static final int MAX_RETRIES = 3;

    /**
     * Instantiates a new lens client singleton wrapper.
     */
    LensClientSingletonWrapper() {
        try {
            client = new LensClient();
        } catch (LensClientServerConnectionException e) {
            if (e.getErrorCode() != 401) {
                explainFailedAttempt(e);
                throw e;
            }
            // Connecting without password prompt failed.
            for (int i = 0; i < MAX_RETRIES; i++) {
                try {
                    client = new LensClient(Credentials.prompt());
                    break;
                } catch (LensClientServerConnectionException lensClientServerConnectionException) {
                    explainFailedAttempt(lensClientServerConnectionException);
                    if (i == MAX_RETRIES - 1) {
                        throw lensClientServerConnectionException;
                    }
                }
            }
        }
    }

    /**
     * Explain failed attempt.
     *
     * @param e the e
     */
    public void explainFailedAttempt(LensClientServerConnectionException e) {
        LOG.error("failed login attempt", e);
        switch (e.getErrorCode()) {
        case 401:
            System.console().printf("username/password combination incorrect.\n");
            break;
        case 500:
            System.console().printf("server unresponsive, Returned error code 500\n");
            break;
        default:
            System.console().printf("Unknown error in authenticating with the server. Error code = %d\n",
                    e.getErrorCode());
        }
    }

    public LensClient getClient() {
        return client;
    }

    public void setClient(LensClient client) {
        this.client = client;
    }

}