org.kiji.examples.phonebook.util.ConsolePrompt.java Source code

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Here is the source code for org.kiji.examples.phonebook.util.ConsolePrompt.java

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/**
 * (c) Copyright 2012 WibiData, Inc.
 *
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * 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 org.kiji.examples.phonebook.util;

import java.io.BufferedReader;
import java.io.Closeable;
import java.io.IOError;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

import org.apache.commons.io.IOUtils;

/**
 * A source of input that delivers prompts to the user and reads responses from the console.
 */
public final class ConsolePrompt implements Closeable {

    /** The underlying reader instance. */
    private BufferedReader mConsoleReader;

    /** Initialize a ConsolePrompt instance. */
    public ConsolePrompt() {
        try {
            mConsoleReader = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
        } catch (UnsupportedEncodingException uee) {
            // UTF-8 is specified as supported everywhere on Java; should not get here.
            throw new IOError(uee);
        }
    }

    /**
     * Display a prompt and then wait for the user to respond with input.
     *
     * @param prompt the prompt string to deliver.
     * @return the user's response.
     * @throws IOError if there was an error reading from the console.
     */
    public String readLine(String prompt) {
        System.out.print(prompt);

        try {
            return mConsoleReader.readLine();
        } catch (IOException ioe) {
            throw new IOError(ioe);
        }
    }

    /**
     * Close all underlying resources.
     */
    @Override
    public void close() {
        IOUtils.closeQuietly(mConsoleReader);
    }
}