package org.neo4j.util.shell.apps.extra;
import java.io.IOException;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.rmi.RemoteException;
import java.util.Map;
import org.neo4j.util.shell.Output;
import org.neo4j.util.shell.ShellException;
/**
* Executes groovy scripts purely via reflection
*/
public class GshExecutor extends ScriptExecutor
{
private static final String BINDING_CLASS = "groovy.lang.Binding";
private static final String ENGINE_CLASS = "groovy.util.GroovyScriptEngine";
@Override
protected String getPathKey()
{
return "GSH_PATH";
}
@Override
protected void runScript( Object groovyScriptEngine,
String scriptName, Map<String, Object> properties, String[] paths )
throws ShellException
{
try
{
properties.put( "out",
new GshOutput( ( Output ) properties.get( "out" ) ) );
Object binding = this.newGroovyBinding( properties );
Method runMethod = groovyScriptEngine.getClass().getMethod(
"run", String.class, binding.getClass() );
runMethod.invoke( groovyScriptEngine, scriptName + ".groovy",
binding );
}
catch ( Exception e )
{
// Don't pass the exception on because the client most certainly
// doesn't have groovy in the classpath.
throw new ShellException( "Groovy exception: " +
this.findProperMessage( e ) );
}
}
private Object newGroovyBinding( Map<String, Object> properties )
throws ShellException
{
try
{
Class<?> cls = Class.forName( BINDING_CLASS );
Object binding = cls.newInstance();
Method setPropertyMethod =
cls.getMethod( "setProperty", String.class, Object.class );
for ( String key : properties.keySet() )
{
setPropertyMethod.invoke( binding, key, properties.get( key ) );
}
return binding;
}
catch ( Exception e )
{
throw new ShellException( "Invalid groovy classes", e );
}
}
@Override
protected Object newInterpreter( String[] paths )
throws ShellException
{
try
{
Class<?> cls = Class.forName( ENGINE_CLASS );
return cls.getConstructor( String[].class ).newInstance(
new Object[] { paths } );
}
catch ( Exception e )
{
throw new ShellException( "Invalid groovy classes", e );
}
}
@Override
protected void ensureDependenciesAreInClasspath() throws ShellException
{
try
{
Class.forName( BINDING_CLASS );
}
catch ( ClassNotFoundException e )
{
throw new ShellException( "Groovy not found in the classpath", e );
}
}
/**
* A wrapper for a supplied {@link Output} to correct a bug where a call
* to "println" or "print" with a GString or another object would use
* System.out instead of the right output instance.
*/
public static class GshOutput implements Output
{
private Output source;
GshOutput( Output output )
{
this.source = output;
}
public void print( Serializable object ) throws RemoteException
{
source.print( object );
}
public void println( Serializable object ) throws RemoteException
{
source.println( object );
}
public Appendable append( char c ) throws IOException
{
return source.append( c );
}
public Appendable append( CharSequence csq, int start, int end )
throws IOException
{
return source.append( csq, start, end );
}
public Appendable append( CharSequence csq ) throws IOException
{
return source.append( csq );
}
/**
* Prints an object to the wrapped {@link Output}.
* @param object the object to print.
* @throws RemoteException RMI error.
*/
public void print( Object object ) throws RemoteException
{
source.print( object.toString() );
}
public void println() throws RemoteException
{
source.println();
}
/**
* Prints an object to the wrapped {@link Output}.
* @param object the object to print.
* @throws RemoteException RMI error.
*/
public void println( Object object ) throws RemoteException
{
source.println( object.toString() );
}
}
}