com.linkedin.bowser.tool.REPLCommandLine.java Source code

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Here is the source code for com.linkedin.bowser.tool.REPLCommandLine.java

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/*
 * Copyright 2010-2011 LinkedIn Corporation
 * 
 * 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.linkedin.bowser.tool;

import java.io.Console;
import java.util.Collections;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.PosixParser;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;

import com.linkedin.bowser.core.exceptions.QueryFormatException;
import com.linkedin.bowser.core.exceptions.QueryRuntimeException;
import com.linkedin.bowser.core.objects.NQLObject;

public class REPLCommandLine {
    private final String _prompt = "nql> ";
    private final String _dots;

    private final REPL _repl;

    public REPLCommandLine(boolean verbose, Integer parallelism) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < _prompt.length() - 1; i++)
            sb.append(".");
        sb.append(" ");
        _dots = sb.toString();

        _repl = new REPL(verbose, parallelism, Collections.<String, NQLObject>emptyMap());
    }

    public static void main(String... args) throws Exception {
        Logger root = Logger.getRootLogger();

        Options options = new Options();
        options.addOption("v", "verbose", false, "verbose output");
        options.addOption("t", "threads", true, "parallel threads");
        CommandLineParser parser = new PosixParser();
        CommandLine cmdline = parser.parse(options, args);

        if (cmdline.hasOption("v"))
            root.setLevel(Level.DEBUG);
        else
            root.setLevel(Level.INFO);

        REPLCommandLine cmd = new REPLCommandLine(cmdline.hasOption("v"),
                cmdline.hasOption("t") ? Integer.parseInt(cmdline.getOptionValue("t")) : null);
        cmd.doRun();
    }

    public void doRun() throws Exception {
        StringBuilder line = new StringBuilder();
        Console console = System.console();

        while (true) {
            String input;
            if (line.length() > 0) {
                input = console.readLine(_dots);
            } else {
                input = console.readLine(_prompt);
                if ("quit".equals(input) || "exit".equals(input))
                    break;
            }

            if (input.endsWith("\\")) {
                line.append(input.substring(0, input.length() - 1));
                line.append("\n");
                continue;
            }

            if (line.length() > 0) {
                input = line.toString() + input;
                line = new StringBuilder();
            }

            try {
                _repl.execute(input, System.out);
            } catch (QueryRuntimeException e) {
                System.err.println(e.getMessage());
            } catch (QueryFormatException e) {
                System.err.println(e.getMessage());
            }
        }
    }

}