/**
* Copyright (c) 2002-2010 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.shell.impl;
import java.io.Serializable;
import java.rmi.RemoteException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import org.neo4j.shell.Console;
import org.neo4j.shell.ShellClient;
import org.neo4j.shell.ShellException;
import org.neo4j.shell.TextUtil;
/**
* A common implementation of a {@link ShellClient}.
*/
public abstract class AbstractClient implements ShellClient
{
/**
* The session key for the prompt key, just like in Bash.
*/
public static final String PROMPT_KEY = "PS1";
/**
* The session key for whether or not to print stack traces for exceptions.
*/
public static final String STACKTRACES_KEY = "STACKTRACES";
/**
* When displaying node ids this variable is also used for getting an
* appropriate property value from that node to display as the title.
* This variable can contain many property keys (w/ regex) separated by
* comma prioritized in order.
*/
public static final String TITLE_KEYS_KEY = "TITLE_KEYS";
/**
* The maximum length of titles to be displayed.
*/
public static final String TITLE_MAX_LENGTH = "TITLE_MAX_LENGTH";
private static final Set<String> EXIT_COMMANDS = new HashSet<String>(
Arrays.asList( "exit", "quit" ) );
private Console console;
private long timeConnection;
private final Set<String> grabbedKeysFromServer = new HashSet<String>();
public void grabPrompt()
{
this.init();
while ( true )
{
try
{
// this.console.format( tryGetProperPromptString() );
String line = this.readLine( tryGetProperPromptString() );
if ( EXIT_COMMANDS.contains( line ) )
{
break;
}
line = expandLine( line );
String result = this.getServer().interpretLine( line, session(), getOutput() );
if ( result == null || result.trim().length() == 0 )
{
continue;
}
if ( result.contains( "e" ) )
{
break;
}
}
catch ( Exception e )
{
if ( this.shouldPrintStackTraces() )
{
e.printStackTrace();
}
this.console.format( getShortExceptionMessage( e ) + "\n" );
}
}
this.shutdown();
}
private String expandLine( String line ) throws RemoteException
{
// Look for environment variables and expand to the real values
return TextUtil.templateString( line, this.session().asMap() );
}
protected String getShortExceptionMessage( Exception e )
{
String result = e instanceof ShellException ?
"" : e.getClass().getName() + ": ";
result += e.getMessage();
return result;
}
protected String tryGetProperPromptString() throws ShellException
{
String result = null;
try
{
result = ( String ) getSessionVariable( PROMPT_KEY, null, true );
}
catch ( Exception e )
{
result = ( String ) getSessionVariable( PROMPT_KEY, null, false );
}
return result;
}
private boolean shouldPrintStackTraces()
{
Object value = this.session().get( STACKTRACES_KEY );
return this.getSafeBooleanValue( value, false );
}
private boolean getSafeBooleanValue( Object value, boolean def )
{
if ( value == null )
{
return def;
}
return Boolean.parseBoolean( value.toString() );
}
private void init()
{
try
{
possiblyGrabDefaultVariableFromServer( PROMPT_KEY, "$ " );
possiblyGrabDefaultVariableFromServer( TITLE_KEYS_KEY, null );
possiblyGrabDefaultVariableFromServer( TITLE_MAX_LENGTH, null );
this.getOutput().println( this.getServer().welcome() );
// Grab a jline console if available, else a standard one.
this.console = JLineConsole.newConsoleOrNullIfNotFound( this );
if ( this.console == null )
{
System.out.println( "Want bash-like features? throw in " +
"jLine (http://jline.sourceforge.net) on the classpath" );
this.console = new StandardConsole();
}
this.getOutput().println();
}
catch ( RemoteException e )
{
throw new RuntimeException( e );
}
}
protected void possiblyGrabDefaultVariableFromServer( String key,
Serializable defaultValue )
{
try
{
if ( this.session().get( key ) == null )
{
grabbedKeysFromServer.add( key );
Serializable value = this.getServer().getProperty( key );
if ( value == null )
{
value = defaultValue;
}
if ( value != null )
{
this.session().set( key, value );
}
}
}
catch ( RemoteException e )
{
throw new RuntimeException( e );
}
}
protected void regrabVariablesFromServer()
{
for ( String key : grabbedKeysFromServer )
{
Serializable value = this.session().remove( key );
possiblyGrabDefaultVariableFromServer( key, value );
}
}
protected Serializable getSessionVariable( String key,
Serializable defaultValue, boolean interpret ) throws ShellException
{
try
{
Serializable result = this.session().get( key );
if ( result == null )
{
result = defaultValue;
}
if ( interpret && result != null )
{
result = this.getServer().interpretVariable( key, result,
session() );
}
return result;
}
catch ( RemoteException e )
{
throw new RuntimeException( e );
}
}
public String readLine( String prompt )
{
return this.console.readLine( prompt );
}
static String[] getExitCommands()
{
return EXIT_COMMANDS.toArray( new String[ EXIT_COMMANDS.size() ] );
}
protected void updateTimeForMostRecentConnection()
{
this.timeConnection = System.currentTimeMillis();
}
public long timeForMostRecentConnection()
{
return timeConnection;
}
}