introspectionutils.java

Tomcat 4.1与WebServer集成组件的源代码包.

                sb.append( value.substring( prev, pos ) );
            }
            if( pos == (value.length() - 1)) {
                sb.append('$');
                prev = pos + 1;
            }
            else if (value.charAt( pos + 1 ) != '{' ) {
                sb.append( value.charAt( pos + 1 ) );
                prev=pos+2; // XXX
            } else {
                int endName=value.indexOf( '}', pos );
                if( endName < 0 ) {
		    sb.append( value.substring( pos ));
		    prev=value.length();
		    continue;
                }
                String n=value.substring( pos+2, endName );
		String v= null;
		if( staticProp != null ) {
		    v=(String)((Hashtable)staticProp).get(n);
		}
                if( v==null && dynamicProp != null) {
                    for( int i=0; i<dynamicProp.length; i++ ) {
                        v=dynamicProp[i].getProperty( n );
                        if( v!=null ) {
                            break;
                        }
                    }
		}
		if( v== null )
		    v = "${"+n+"}"; 
                
                sb.append( v );
                prev=endName+1;
            }
        }
        if( prev < value.length() ) sb.append( value.substring( prev ) );
        return sb.toString();
    }
    
    /** Reverse of Introspector.decapitalize
     */
    public static String capitalize(String name) {
	if (name == null || name.length() == 0) {
	    return name;
	}
	char chars[] = name.toCharArray();
	chars[0] = Character.toUpperCase(chars[0]);
	return new String(chars);
    }

    public static String unCapitalize(String name) {
	if (name == null || name.length() == 0) {
	    return name;
	}
	char chars[] = name.toCharArray();
	chars[0] = Character.toLowerCase(chars[0]);
	return new String(chars);
    }

    // -------------------- Class path tools --------------------

    /** Add all the jar files in a dir to the classpath,
     *  represented as a Vector of URLs.
     */ 
    public static void addToClassPath( Vector cpV, String dir ) {
	try{
            String cpComp[]=getFilesByExt(dir, ".jar");
            if (cpComp != null){
                int jarCount=cpComp.length;
                for( int i=0; i< jarCount ; i++ ) {
		    URL url=getURL(  dir , cpComp[i] );
                    if( url!=null )
			cpV.addElement( url );
                }
            }
        }catch(Exception ex){
            ex.printStackTrace();
        }
    }


    public static void addToolsJar( Vector v )
    {
	try {
            // Add tools.jar in any case
            File f=new File( System.getProperty( "java.home" ) +
                             "/../lib/tools.jar");

            if( ! f.exists() ) {
                // On some systems java.home gets set to the root of jdk.
                // That's a bug, but we can work around and be nice.
                f=new File( System.getProperty( "java.home" ) +
                                 "/lib/tools.jar");
                if( f.exists() ) {
                    System.out.println("Detected strange java.home value " +
                                       System.getProperty( "java.home" ) +
                                       ", it should point to jre");
                }
            }
            URL url=new URL( "file", "" , f.getAbsolutePath() );

	    v.addElement( url );
	} catch ( MalformedURLException ex ) {
	    ex.printStackTrace();
	}
    }

    
    /** Return all files with a given extension in a dir
     */
    public static String[] getFilesByExt( String ld, String ext ) {
	File dir = new File(ld);
        String[] names=null;
	final String lext=ext;
        if (dir.isDirectory()){
            names = dir.list( new FilenameFilter(){
            public boolean accept(File d, String name) {
                if (name.endsWith(lext)){
                    return true;
                }
                return false;
            }
            });
        }
	return names;
    }


    /** Construct a file url from a file, using a base dir
     */
    public static URL getURL( String base, String file ) {
        try {
            File baseF = new File(base);
            File f = new File(baseF,file);
            String path = f.getCanonicalPath();
            if( f.isDirectory() ){
                    path +="/";
            }
	    if( ! f.exists() ) return null;
            return new URL( "file", "", path );
        } catch (Exception ex) {
            ex.printStackTrace();
            return null;
        }
    }

    /**
     * add elements from the classpath <i>cp</i> to a Vector
     * <i>jars</i> as file URLs (We use Vector for JDK 1.1 compat).
     * <p>
     * @param <b>cp</b> a String classpath of directory or jar file
     *                    elements separated by path.separator delimiters.
     * @return a Vector of URLs.
     */
    public static void addJarsFromClassPath(Vector jars, String cp)
            throws IOException,MalformedURLException
    {
        String sep = System.getProperty("path.separator");
        String token;
        StringTokenizer st;
        if(cp!=null){
            st = new StringTokenizer(cp,sep);
            while(st.hasMoreTokens()){
                File f = new File(st.nextToken());
                String path = f.getCanonicalPath();
                if(f.isDirectory()){
                        path += "/";
                }
                URL url = new URL("file","",path);
                if(!jars.contains(url)){
                        jars.addElement(url);
                }
            }
        }
    }

    /** Return a URL[] that can be used to construct a class loader
     */
    public static URL[] getClassPath(Vector v){
        URL[] urls=new URL[ v.size() ];
        for( int i=0; i<v.size(); i++ ) {
            urls[i]=(URL)v.elementAt( i );
        }
        return urls;
    }

    /** Construct a URL classpath from files in a directory,
     *  a cpath property, and tools.jar.
     */
    public static URL[] getClassPath( String dir, String cpath,
				      String cpathProp, boolean addTools )
	throws IOException, MalformedURLException
    {
	Vector jarsV = new Vector();
	if( dir!=null ) {
	    // Add dir/classes first, if it exists
	    URL url=getURL( dir, "classes");
	    if( url!=null )
		jarsV.addElement(url);
	    addToClassPath( jarsV, dir );
	}
	
	if( cpath != null )
	    addJarsFromClassPath(jarsV,cpath);
	
	if( cpathProp!=null ) {
	    String cpath1=System.getProperty( cpathProp );
	    addJarsFromClassPath(jarsV,cpath1);
	}

	if(addTools)
	    addToolsJar( jarsV );
	
	return getClassPath(jarsV);
    }
    
    // -------------------- Mapping command line params to setters

    public static boolean processArgs(Object proxy, String args[] ) 
	throws Exception
    {
	String args0[]=null;
	if( null != findMethod( proxy.getClass(),
				"getOptions1", new Class[] {} )) {
	    args0=(String[])callMethod0( proxy, "getOptions1");
	}

	if( args0==null ) {
	    //args0=findVoidSetters(proxy.getClass());
	    args0=findBooleanSetters(proxy.getClass());
	}
	Hashtable h=null;
	if( null != findMethod( proxy.getClass(),
				"getOptionAliases", new Class[] {} )) {
	    h=(Hashtable)callMethod0( proxy, "getOptionAliases");
	}
	return processArgs( proxy, args, args0, null, h );
    }

    public static boolean processArgs(Object proxy, String args[],
				      String args0[], String args1[],
				      Hashtable aliases )
	throws Exception
    {
	for( int i=0; i< args.length; i++ ) {
	    String arg=args[i];
	    if( arg.startsWith("-"))
		arg=arg.substring(1);
	    if( aliases != null && aliases.get( arg ) != null)
		arg=(String)aliases.get(arg);

	    if( args0!=null ) {
		boolean set=false;
		for( int j=0; j< args0.length ; j++ ) {
		    if( args0[j].equalsIgnoreCase( arg )) {
			setProperty( proxy, args0[j], "true");
			set=true;
			break;
		    }
		}
		if( set ) continue;
	    }
	    if( args1!=null ) {
		for( int j=0; j< args1.length ; j++ ) {
		    if( args1[j].equalsIgnoreCase( arg )) {
			i++;
			if( i >= args.length )
			    return false;
			setProperty( proxy, arg, args[i]);
			break;
		    }
		}
	    } else {
		// if args1 is not specified,assume all other options have param
		i++;
		if( i >= args.length )
		    return false;
		setProperty( proxy,arg, args[i]);
	    }

	}
	return true;
    }

    // -------------------- other utils  --------------------
    public static String[] findVoidSetters( Class c ) {
	Method m[]=findMethods( c );
	if( m==null ) return null;
	Vector v=new Vector();
	for( int i=0; i<m.length; i++ ) {
	    if( m[i].getName().startsWith("set") &&
		m[i].getParameterTypes().length == 0 ) {
		String arg=m[i].getName().substring( 3 );
		v.addElement( unCapitalize( arg ));
	    }
	}
	String s[]=new String[v.size()];
	for( int i=0; i<s.length; i++ ) {
	    s[i]=(String)v.elementAt( i );
	}
	return s;
    }

    public static String[] findBooleanSetters( Class c ) {
	Method m[]=findMethods( c );
	if( m==null ) return null;
	Vector v=new Vector();
	for( int i=0; i<m.length; i++ ) {
	    if( m[i].getName().startsWith("set") &&
	    	m[i].getParameterTypes().length == 1 &&
	    	"boolean".equalsIgnoreCase( m[i].getParameterTypes()[0].getName()) ) {
	    	String arg=m[i].getName().substring( 3 );
	    	v.addElement( unCapitalize( arg ));
	    } 
	}
	String s[]=new String[v.size()];
	for( int i=0; i<s.length; i++ ) {
	    s[i]=(String)v.elementAt( i );
	}
	return s;
    }
    
    static Hashtable objectMethods=new Hashtable();

    public static Method[] findMethods( Class c ) {
	Method methods[]= (Method [])objectMethods.get( c );
	if( methods != null ) return methods;
	
	methods=c.getMethods();
	objectMethods.put( c, methods );
	return methods;
    }

    public static Method findMethod( Class c, String name, Class params[] ) {
	Method methods[] = findMethods( c );
	if( methods==null ) return null;
	for (int i = 0; i < methods.length; i++) {
	    if (methods[i].getName().equals(name) ) {
		Class methodParams[]=methods[i].getParameterTypes();
		if( methodParams==null )
		    if( params==null || params.length==0 )
			return methods[i];
		if( params==null )
		    if( methodParams==null || methodParams.length==0 )
			return methods[i];
		if( params.length != methodParams.length )
		    continue;
		boolean found=true;
		for( int j=0; j< params.length; j++ ) {
		    if( params[j] != methodParams[j] ) {
			found=false;
			break;
		    }
		}
		if( found ) return methods[i];
	    }
	}
	return null;
    }
    
    /** Test if the object implements a particular
     *  method
     */
    public static boolean hasHook( Object obj, String methodN ) {
	try {
	    Method myMethods[]=findMethods( obj.getClass() );
	    for( int i=0; i< myMethods.length; i++ ) {
		if( methodN.equals ( myMethods[i].getName() )) {
		    // check if it's overriden
		    Class declaring=myMethods[i].getDeclaringClass();
		    Class parentOfDeclaring=declaring.getSuperclass();
		    // this works only if the base class doesn't extend
		    // another class.

		    // if the method is declared in a top level class
		    // like BaseInterceptor parent is Object, otherwise
		    // parent is BaseInterceptor or an intermediate class
		    if( ! "java.lang.Object".
			equals(parentOfDeclaring.getName() )) {
			return true;
		    }
		}
	    }
	} catch ( Exception ex ) {
	    ex.printStackTrace();
	}
	return false;
    }

    public static void callMain( Class c, String args[] )
	throws Exception
    {
	Class p[]=new Class[1];
	p[0]=args.getClass();
	Method m=c.getMethod( "main", p);
	m.invoke( c, new Object[] {args} );
    }
    
    public static Object callMethod1( Object target,
				    String methodN,
				    Object param1,
				    String typeParam1,
				    ClassLoader cl)
	throws Exception
    {
	if( target==null || param1==null ) {
	    d("Assert: Illegal params " + target + " " + param1 );
	}
	if( dbg > 0 ) d("callMethod1 " + target.getClass().getName() +
			" " + param1.getClass().getName() +
			" " + typeParam1 );
	
	Class params[]=new Class[1];
	if( typeParam1==null )
	    params[0]=param1.getClass();
	else
	    params[0]=cl.loadClass( typeParam1 );
	Method m=findMethod( target.getClass(), methodN, params);
	if( m==null )
	    throw new NoSuchMethodException(target.getClass().getName() +
					    " " + methodN);
	return m.invoke(target,  new Object[] {param1 } );
    }

    public static Object callMethod0( Object target,
				    String methodN)
	throws Exception
    {
	if( target==null ) {
	    d("Assert: Illegal params " + target );
	    return null;
	}
	if( dbg > 0 )
	    d("callMethod0 " + target.getClass().getName() + "." + methodN);
	
	Class params[]=new Class[0];
	Method m=findMethod( target.getClass(), methodN, params);
	if( m==null )
	    throw new NoSuchMethodException(target.getClass().getName() +
					    " " + methodN);
	return m.invoke(target,  emptyArray );
    }
    
    static Object[] emptyArray=new Object[] {};
    
    public static Object callMethodN( Object target,  String methodN,
				    Object params[],  Class typeParams[] )
	throws Exception
    {
	Method m=null;
	m=findMethod( target.getClass(), methodN, typeParams );
        if( m== null ) {
	    d("Can't find method " + methodN + " in " +
	      target + " CLASS " + target.getClass());
	    return null;
	}
	Object o=m.invoke( target, params );

	if(dbg > 0 ) {
	    // debug
	    StringBuffer sb=new StringBuffer();
	    sb.append("" + target.getClass().getName() + "." + methodN + "( " );
	    for(int i=0; i<params.length; i++ ) {
		if(i>0) sb.append( ", ");
		sb.append(params[i]);
	    }
	    sb.append(")");
	    d(sb.toString());
	}
	return o;
    }
    
    // -------------------- Get property --------------------
    // This provides a layer of abstraction

    public static interface PropertySource {

	public String getProperty( String key );
	
    }

    public static interface AttributeHolder {

	public void setAttribute( String key, Object o );
	
    }


    // debug --------------------
    static final int dbg=0;
    static void d(String s ) {
	System.out.println("IntrospectionUtils: " + s );
    }
}