yanmnode helper for SnakeYAML

yamlnode.java

//
//	YamlNode helper
//	author: mpenzin@gmail.com
//	date: 2010-02-22
//

package util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Logger;

// - - -
import java.io.File;
import java.io.FileInputStream;
import org.yaml.snakeyaml.Yaml;
// - - -
	
public class YamlNode 
{
	String val;
	
	Map<String,YamlNode>	map;
	List<YamlNode> 			lst;

	static final Logger L = Logger.getLogger(YamlNode.class.getName());
	
	static HashMap<String,Boolean> BOOL_VAL = new HashMap<String,Boolean>();
	static {
		BOOL_VAL.put( "", false );
		BOOL_VAL.put( "0", false );
		BOOL_VAL.put( "no", false );
		BOOL_VAL.put( "false", false );
		BOOL_VAL.put( "1", true );
		BOOL_VAL.put( "yes", true );
		BOOL_VAL.put( "true", true );
	}
	
	static final YamlNode NULL_NODE = new YamlNode( null );
	

	public YamlNode( String val )
	{
		this.val = val;
	}

	public boolean is_null() 
	{ 
		return (this.val == null && this.map == null && this.lst == null); 
	}
	
	@SuppressWarnings("unchecked")
	public YamlNode( Object yaml_tree )
	{
	
		if( yaml_tree instanceof List<?> ) 
		{
			this.lst = new ArrayList<YamlNode>();
			for( Object n: (List<Object>)yaml_tree )
			{
				this.lst.add( new YamlNode(n) );
			}
		}
		else if( yaml_tree instanceof Map<?,?> ) 
		{
			this.map = new HashMap<String,YamlNode>();
			for( Map.Entry<String, Object> m: ((Map<String,Object>)yaml_tree).entrySet() )
			{
				this.map.put( m.getKey(), new YamlNode( m.getValue() ) );
			}
		}
		else {
			this.val = (yaml_tree != null)? yaml_tree.toString(): null;
		}
	}
	
	public boolean bool()
	{ 
		return this.bool(false); 
	}
	
	public boolean bool( boolean def )
	{
		if( this.val == null ) return def;
		Boolean b = BOOL_VAL.get( this.val.trim().toLowerCase() );
		return (b != null)? b.booleanValue(): def;
	}

	public int num()
	{ 
		return this.num(0); 
	}
	
	public int num( int def )
	{
		try { return Integer.parseInt(this.val); } 
		catch( Exception ign ) { return def; }
	}

	public String str()
	{ 
		return this.str(""); 
	}
	
	public String str( String def )
	{
		return (this.val != null)? this.val: def;
	}

	public List<YamlNode> list()
	{ 
		return (this.lst != null)? this.lst: Collections.<YamlNode>emptyList();
	}
	
	public Collection<String> keys()
	{
		return (this.map != null)? this.map.keySet(): Collections.<String>emptyList(); 
	}
	
	public YamlNode item( String key )
	{
		if( this.map == null ) return NULL_NODE;
		YamlNode n = this.map.get(key);
		return (n != null)? n: NULL_NODE;
	}

	
	public static YamlNode load( File yf )
	{
		try {
			return new YamlNode( new Yaml().load( new FileInputStream( yf ) ) );
		}
		catch( Exception ex ) {
			L.warning("YamlNode.load("+yf+") "+ex.toString());
		}
		return NULL_NODE;
	}
	
// - - - 
	
	public static void main( String[] argv )
	{
		YamlNode root = YamlNode.load( new File("/path/to/file.yaml") ); 
			
		for( YamlNode n: root.list() ) {
			System.out.println( "id: "+n.item("id").str() );
			System.out.println( "addr: "+n.item("town").str()+" "+n.item("addr").str() );
			System.out.println( "note: "+n.item("note").str() );
			
			for( YamlNode li: n.item("test").list() ) {
				System.out.println( "test item: "+li.str() );
			}
		}
	}
	
}

//.