Add a task to load properties from a property file - optionally with a specified prefix

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@270525 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/antlib/core/LoadProperties.java

@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.antlib.core;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.Properties;
+import org.apache.avalon.excalibur.i18n.ResourceManager;
+import org.apache.avalon.excalibur.i18n.Resources;
+import org.apache.avalon.excalibur.io.IOUtil;
+import org.apache.myrmidon.api.TaskException;
+import org.apache.myrmidon.framework.AbstractContainerTask;
+
+/**
+ * This task loads properties from a property file and places them in the context.
+ *
+ * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ */
+public class LoadProperties
+    extends AbstractContainerTask
+{
+    private static final Resources REZ =
+        ResourceManager.getPackageResources( LoadProperties.class );
+
+    private String m_prefix;
+    private File m_file;
+
+    /**
+     * Specify the prefix to be placed before all properties (if any).
+     */
+    public void setPrefix( final String prefix )
+    {
+        m_prefix = prefix;
+    }
+
+    public void setFile( final File file )
+    {
+        m_file = file;
+    }
+
+    public void execute()
+        throws TaskException
+    {
+        if( null == m_file )
+        {
+            final String message = REZ.getString( "loadprop.no-file.error" );
+            throw new TaskException( message );
+        }
+
+        //Make sure prefix ends with a '.' if specified
+        if( null == m_prefix )
+        {
+            m_prefix = "";
+        }
+        else if( !m_prefix.endsWith( "." ) )
+        {
+            m_prefix += ".";
+        }
+
+        loadFile( m_file );
+    }
+
+    /**
+     * Utility method to load properties file.
+     */
+    private void loadFile( final File file )
+        throws TaskException
+    {
+        if( getLogger().isDebugEnabled() )
+        {
+            final String message =
+                REZ.getString( "loadprop.file.notice", file.getAbsolutePath() );
+            getLogger().debug( message );
+        }
+
+        if( !file.exists() )
+        {
+            final String message =
+                REZ.getString( "loadprop.missing-file.notice", file.getAbsolutePath() );
+            getLogger().debug( message );
+        }
+        else
+        {
+            FileInputStream input = null;
+
+            try
+            {
+                input = new FileInputStream( file );
+                final Properties properties = new PropertyLoader( this );
+                properties.load( input );
+            }
+            catch( final IOException ioe )
+            {
+                throw new TaskException( ioe.getMessage(), ioe );
+            }
+
+            IOUtil.shutdownStream( input );
+        }
+    }
+
+    /**
+     * Utility method that will resolve and add specified proeprty.
+     * Used by external PropertyLoader class as a call back method.
+     */
+    protected final void addUnresolvedValue( final String name, final String value )
+    {
+        try
+        {
+            final Object objectValue = resolveValue( value.toString() );
+            setProperty( m_prefix + name, objectValue );
+        }
+        catch( final TaskException te )
+        {
+            final String message = REZ.getString( "loadprop.bad-resolve.error", name, value );
+            getLogger().info( message, te );
+        }
+    }
+}

proposal/myrmidon/src/java/org/apache/antlib/core/PropertyLoader.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.antlib.core;
+
+import java.util.Properties;
+
+/**
+ * This class is an UGLY HACK utility class to enable us to reuse
+ * the property parsing and loading code from Properties object.
+ */
+class PropertyLoader
+    extends Properties
+{
+    private LoadProperties m_loadProperties;
+
+    public PropertyLoader( LoadProperties loadProperties )
+    {
+        m_loadProperties = loadProperties;
+    }
+
+    /**
+     * Overidden put to add unresolved values.
+     */
+    public synchronized Object put( Object key, Object value )
+    {
+        m_loadProperties.addUnresolvedValue( key.toString(), value.toString() );
+        return null;
+    }
+}

proposal/myrmidon/src/java/org/apache/antlib/core/Resources.properties

@@ -4,6 +4,11 @@ property.multi-set.error=Value can not be set multiple times.
 property.no-name.error=Name must be specified.
 property.no-value.error=Value must be specified.
 
+loadprop.no-file.error=No file specified to load properties from.
+loadprop.file.notice=Loading proeprties from {0}.
+loadprop.missing-file.notice=Unable to find property file: {0}.
+loadprop.bad-resolve.error=Unable to resolve and set property named "{0}" to value "{1}".
+
 convert.bad-byte.error=Error converting object ({0}) to Byte.
 convert.bad-class.error=Error converting object ({0}) to Class.
 convert.bad-double.error=Error converting object ({0}) to Double.