Groovy example source code file (ErrorReporter.java)

This example Groovy source code file (ErrorReporter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

compilationfailedexception, compilationfailedexception, errorreporter, exception, exception, groovyexceptioninterface, groovyruntimeexception, io, object, printstream, printstream, printwriter, the, throwable, throwable

The Groovy ErrorReporter.java source code

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * 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.codehaus.groovy.tools;

import java.io.PrintStream;
import java.io.PrintWriter;

import org.codehaus.groovy.GroovyExceptionInterface;
import org.codehaus.groovy.control.CompilationFailedException;
import groovy.lang.GroovyRuntimeException;


/**
 *  Provides services for reporting compilation errors to the
 *  user.  Primary entry point is <code>write().
 *
 *  @author <a href="mailto:cpoirier%20AT%20tapestry_os%20DOT%20org">Chris Poirier
 *  @version $Revision: 6778 $
 */

public class ErrorReporter
{
    private Throwable   base     = null;    // The exception on which to report
    private boolean     debug    = false;   // If true, stack traces are always output

    private Object      output   = null;    // The stream/writer to which to output


   /**
    *  Configures a new Reporter.  Default mode is not to report a stack trace unless
    *  the error was not of one of the supported types.
    *
    *  @param e  the exception on which to report
    */

    public ErrorReporter( Throwable e )
    {
        this.base     = e;
    }


   /**
    *  Configures a new Reporter.  
    *
    *  @param e      the exception on which to report
    *  @param debug  if set, stack traces will be output for all reports
    */

    public ErrorReporter( Throwable e, boolean debug )
    {
        this.base  = e;
        this.debug = debug;
    }


   /**
    *  Writes the error to the specified <code>PrintStream.
    */

    public void write( PrintStream stream )
    {
        this.output = stream;
        dispatch( base, false );
        stream.flush();
    }


   /**
    *  Writes the error to the specified <code>PrintWriter.
    */

    public void write( PrintWriter writer )
    {
        this.output = writer;
        dispatch( base, false );
        writer.flush();
    }


   /**
    *  Runs the report once all initialization is complete.
    */

    protected void dispatch( Throwable object, boolean child )
    {
        if( object instanceof CompilationFailedException )
        {
            report( (CompilationFailedException)object, child );
        }
        else if( object instanceof GroovyExceptionInterface )
        {
            report( (GroovyExceptionInterface)object, child );
        }
        else if( object instanceof GroovyRuntimeException )
        {
            report( (GroovyRuntimeException)object, child );
        }
        else if( object instanceof Exception )
        {
            report( (Exception)object, child );
        }
        else
        {
            report( object, child );
        }

    }



  //---------------------------------------------------------------------------
  // REPORTING ROUTINES


   /**
    *  For CompilationFailedException.
    */

    protected void report( CompilationFailedException e, boolean child )
    {
        println( e.toString() );
        stacktrace( e, false );
    }



   /**
    *  For GroovyException.
    */

    protected void report( GroovyExceptionInterface e, boolean child )
    {
        println( ((Exception)e).getMessage() );
        stacktrace( (Exception)e, false );
    }



   /**
    *  For Exception.
    */

    protected void report( Exception e, boolean child )
    {
        println( e.getMessage() );
        stacktrace( e, false );
    }



   /**
    *  For everything else.
    */

    protected void report( Throwable e, boolean child )
    {
        println( ">>> a serious error occurred: " + e.getMessage() );
        stacktrace( e, true );
    }



  //---------------------------------------------------------------------------
  // GENERAL SUPPORT ROUTINES


   /**
    *  Prints a line to the underlying <code>PrintStream
    */

    protected void println( String line )
    {
        if( output instanceof PrintStream )
        {
            ((PrintStream)output).println( line );
        }
        else
        {
            ((PrintWriter)output).println( line );
        }
    }

    protected void println( StringBuffer line )
    {
        if( output instanceof PrintStream )
        {
            ((PrintStream)output).println( line );
        }
        else
        {
            ((PrintWriter)output).println( line );
        }
    }


   /**
    *  Displays an exception's stack trace, if <code>debug or 
    *  <code>always.
    */

    protected void stacktrace( Throwable e, boolean always )
    {
        if( debug || always )
        {
            println( ">>> stacktrace:" );
            if( output instanceof PrintStream )
            {
                e.printStackTrace( (PrintStream)output );
            }
            else
            {
                e.printStackTrace( (PrintWriter)output );
            }
        }
    }



}