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Commons Modeler example source code file (IntrospectionUtils.java)

This example Commons Modeler source code file (IntrospectionUtils.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 - Commons Modeler tags/keywords

class, class, exception, file, hashtable, io, method, method, net, network, object, object, propertysource, reflection, string, string, url, util, vector

The Commons Modeler IntrospectionUtils.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.commons.modeler.util;

import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.UnknownHostException;
import java.util.Hashtable;
import java.util.StringTokenizer;
import java.util.Vector;

// Depends:
//    JDK1.1

/**
 *  Utils for introspection and reflection
 *
 *  Source: jakarta-tomcat-connector/util
 */
public final class IntrospectionUtils {
    static final Class NO_PARAMS[]=new Class[0];
    static final Class STRING_OBJ_PARAM[]=new Class[] {
        String.class, Object.class };
    static final Class STRING_PARAM[]=new Class[] {
        String.class };

    /** Execute a no-param method.
     */
    public static void execute( Object proxy, String method  )
	throws Exception
    {
	Method executeM=null;
	Class c=proxy.getClass();
	executeM=findMethod( c, method, NO_PARAMS );
	if( executeM == null ) {
	    throw new RuntimeException("No method " + method + " in " +
                    proxy.getClass() );
	}
	executeM.invoke(proxy, (Object [])null );
    }

    /**
     *  Call void setAttribute( String ,Object )
     */
    public static void setAttribute( Object proxy, String n, Object v)
	throws Exception
    {
	if( proxy instanceof AttributeHolder ) {
	    ((AttributeHolder)proxy).setAttribute( n, v );
	    return;
	}

	Method executeM=null;
	Class c=proxy.getClass();
	executeM=findMethod( c, "setAttribute", STRING_OBJ_PARAM );

	if( executeM == null ) {
	    System.out.println("No setAttribute in " + proxy.getClass() );
	    return;
	}
	executeM.invoke(proxy, new Object[] { n, v });
	return;
    }


    /**
     *  Call void getAttribute( String )
     */
    public static Object getAttribute( Object proxy, String n)
	throws Exception
    {
	Method executeM=null;
	Class c=proxy.getClass();
	executeM=findMethod( c, "getAttribute", STRING_PARAM);
	if( executeM == null ) {
	    System.out.println("No getAttribute in " + proxy.getClass() );
	    return null;
	}
	return executeM.invoke(proxy, new Object[] { n });
    }


    /** Construct a URLClassLoader. Will compile and work in JDK1.1 too.
     */
    public static ClassLoader getURLClassLoader( URL urls[],
						 ClassLoader parent )
    {
	try {
	    Class urlCL=Class.forName( "java.net.URLClassLoader");
	    Class paramT[]=new Class[2];
	    paramT[0]= urls.getClass();
	    paramT[1]=ClassLoader.class;
	    Method m=findMethod( urlCL, "newInstance", paramT);
	    if( m==null ) return null;

	    ClassLoader cl=(ClassLoader)m.invoke( urlCL,
						  new Object[] { urls,
								 parent } );
	    return cl;
	} catch(ClassNotFoundException ex ) {
	    // jdk1.1
	    return null;
	} catch(Exception ex ) {
	    ex.printStackTrace();
	    return null;
	}
    }


    public static String guessInstall(String installSysProp,
		String homeSysProp, String jarName) {
	return guessInstall( installSysProp, homeSysProp, jarName, null);
    }

    /** Guess a product install/home by analyzing the class path.
     *  It works for product using the pattern: lib/executable.jar
     *  or if executable.jar is included in classpath by a shell
     *  script. ( java -jar also works )
     *
     *  Insures both "install" and "home" System properties are set.
     *  If either or both System properties are unset, "install" and
     *  "home" will be set to the same value.  This value will be
     *  the other System  property that is set, or the guessed value
     *  if neither is set.
     */
    public static String guessInstall(String installSysProp, String homeSysProp,
			String jarName,	String classFile) {
	String install=null;
	String home=null;

	if ( installSysProp != null )
	    install=System.getProperty( installSysProp );

	if( homeSysProp != null )
	    home=System.getProperty( homeSysProp );

	if ( install != null ) {
	    if ( home == null )
		System.getProperties().put( homeSysProp, install );
	    return install;
	}

	// Find the directory where jarName.jar is located

	String cpath=System.getProperty( "java.class.path");
	String pathSep=System.getProperty( "path.separator");
	StringTokenizer st=new StringTokenizer( cpath, pathSep );
	while( st.hasMoreTokens() ) {
	    String path=st.nextToken();
	    //	    log( "path " + path );
	    if( path.endsWith( jarName ) ) {
		home=path.substring( 0, path.length() - jarName.length() );
		try {
                    if( "".equals(home) ) {
                        home=new File("./").getCanonicalPath();
                    } else if( home.endsWith(File.separator) ) {
			home = home.substring(0,home.length()-1);
		    }
                    File f=new File( home );
		    String parentDir = f.getParent();
		    if(parentDir == null)
			parentDir = home;  // unix style
		    File f1=new File ( parentDir );
		    install = f1.getCanonicalPath();
		    if( installSysProp != null )
			System.getProperties().put( installSysProp, install );
		    if( home == null && homeSysProp != null )
			System.getProperties().put( homeSysProp, install );
		    return install;
		} catch( Exception ex ) {
		    ex.printStackTrace();
		}
	    } else  {
		String fname=path + ( path.endsWith("/") ?"":"/" ) + classFile;
		if( new File( fname ).exists()) {
		    try {
			File f=new File( path );
			String parentDir = f.getParent();
			if( parentDir == null )
			    parentDir = path; // unix style
			File f1=new File ( parentDir );
			install = f1.getCanonicalPath();
			if( installSysProp != null )
			    System.getProperties().put( installSysProp,
							install );
			if( home == null && homeSysProp != null )
			    System.getProperties().put( homeSysProp, install );
			return install;
		    } catch( Exception ex ) {
			ex.printStackTrace();
		    }
		}
	    }
	}

        // if install directory can't be found, use home as the default
	if ( home != null ) {
	    System.getProperties().put( installSysProp, home );
	    return home;
	}

	return null;
    }

    /** Debug method, display the classpath
     */
    public static void displayClassPath( String msg, URL[] cp ) {
	System.out.println(msg);
	for( int i=0; i<cp.length; i++ ) {
	    System.out.println( cp[i].getFile() );
	}
    }

    public static String PATH_SEPARATOR = System.getProperty("path.separator");
    /**
     * Adds classpath entries from a vector of URL's to the
     * "tc_path_add" System property.  This System property lists
     * the classpath entries common to web applications. This System
     * property is currently used by Jasper when its JSP servlet
     * compiles the Java file for a JSP.
    */
    public static String classPathAdd(URL urls[], String cp )
    {
	if( urls==null ) return cp;

	for( int i=0; i<urls.length; i++ ) {
            if( cp != null)
                cp += PATH_SEPARATOR + urls[i].getFile();
            else
                cp = urls[i].getFile();
        }
        return cp;
    }

    /** Find a method with the right name
	If found, call the method ( if param is int or boolean we'll convert
	value to the right type before) - that means you can have setDebug(1).
    */
    public static void setProperty( Object o, String name, String value ) {
	if( dbg > 1 ) d("setProperty(" +
			o.getClass() + " " +  name + "="  +
			value  +")" );

	String setter= "set" +capitalize(name);

	try {
	    Method methods[]=findMethods( o.getClass() );
	    Method setPropertyMethod=null;

	    // First, the ideal case - a setFoo( String ) method
	    for( int i=0; i< methods.length; i++ ) {
		Class paramT[]=methods[i].getParameterTypes();
		if( setter.equals( methods[i].getName() ) &&
		    paramT.length == 1 &&
		    "java.lang.String".equals( paramT[0].getName())) {

		    methods[i].invoke( o, new Object[] { value } );
		    return;
		}
	    }

	    // Try a setFoo ( int ) or ( boolean )
	    for( int i=0; i< methods.length; i++ ) {
		boolean ok=true;
		if( setter.equals( methods[i].getName() ) &&
		    methods[i].getParameterTypes().length == 1) {

		    // match - find the type and invoke it
		    Class paramType=methods[i].getParameterTypes()[0];
		    Object params[]=new Object[1];

		    // Try a setFoo ( int )
		    if ("java.lang.Integer".equals( paramType.getName()) ||
			"int".equals( paramType.getName())) {
			try {
			    params[0]=new Integer(value);
			} catch( NumberFormatException ex ) {ok=false;}

		    // Try a setFoo ( boolean )
		    } else if ("java.lang.Boolean".
			       equals( paramType.getName()) ||
			"boolean".equals( paramType.getName())) {
			params[0]=new Boolean(value);

		    // Try a setFoo ( InetAddress )
		    } else if ("java.net.InetAddress".
				equals( paramType.getName())){
			try{
 			    params[0]= InetAddress.getByName(value);
 			}catch(UnknownHostException exc) {
 			    d("Unable to resolve host name:" + value);
 			    ok=false;
 			}

                    // Try a setFoo ( Object )
                    } else if ("java.lang.Object".
                               equals( paramType.getName())) {
                        params[0] = value;

 		    // Unknown type
		    } else {
			d("Unknown type " + paramType.getName() );
		    }

		    if( ok ) {
			methods[i].invoke( o, params );
			return;
		    }
		}

		// save "setProperty" for later
		if( "setProperty".equals( methods[i].getName())) {
		    setPropertyMethod=methods[i];
		}
	    }

	    // Ok, no setXXX found, try a setProperty("name", "value")
	    if( setPropertyMethod != null ) {
		Object params[]=new Object[2];
		params[0]=name;
		params[1]=value;
		setPropertyMethod.invoke( o, params );
	    }

	} catch( IllegalArgumentException ex2 ) {
            System.err.println("IAE " + o + " " + name + " " + value);
            ex2.printStackTrace();
	} catch( SecurityException ex1 ) {
	    if( dbg > 0 )
		d("SecurityException for " + o.getClass() + " " +
			name + "="  + value  +")" );
	    if( dbg > 1 ) ex1.printStackTrace();
	} catch (IllegalAccessException iae) {
	    if( dbg > 0 )
		d("IllegalAccessException for " +
			o.getClass() + " " +  name + "="  + value  +")" );
	    if( dbg > 1 ) iae.printStackTrace();
	} catch (InvocationTargetException ie) {
	    if( dbg > 0 )
		d("InvocationTargetException for " + o.getClass() +
			" " +  name + "="  + value  +")" );
	    if( dbg > 1 ) ie.printStackTrace();
	}
    }

    public static Object getProperty( Object o, String name ) {
	String getter= "get" +capitalize(name);

	try {
	    Method methods[]=findMethods( o.getClass() );
	    Method getPropertyMethod=null;

	    // First, the ideal case - a getFoo() method
	    for( int i=0; i< methods.length; i++ ) {
		Class paramT[]=methods[i].getParameterTypes();
		if( getter.equals( methods[i].getName() ) &&
		    paramT.length == 0 ) {
		    return methods[i].invoke( o, (Object [])null );
		}

		if( "getProperty".equals( methods[i].getName())) {
		    getPropertyMethod=methods[i];
		}
		if( "getAttribute".equals( methods[i].getName())) {
		    getPropertyMethod=methods[i];
		}
	    }

	    // Ok, no setXXX found, try a getProperty("name")
	    if( getPropertyMethod != null ) {
		Object params[]=new Object[1];
		params[0]=name;
		getPropertyMethod.invoke( o, params );
	    }

	} catch( IllegalArgumentException ex2 ) {
            System.err.println("IAE " + o + " " + name );
            ex2.printStackTrace();
	} catch( SecurityException ex1 ) {
	    if( dbg > 0 )
		d("SecurityException for " + o.getClass() + " " +
			name + ")" );
	    if( dbg > 1 ) ex1.printStackTrace();
	} catch (IllegalAccessException iae) {
	    if( dbg > 0 )
		d("IllegalAccessException for " +
			o.getClass() + " " +  name  +")" );
	    if( dbg > 1 ) iae.printStackTrace();
	} catch (InvocationTargetException ie) {
	    if( dbg > 0 )
		d("InvocationTargetException for " + o.getClass() +
			" " +  name   +")" );
	    if( dbg > 1 ) ie.printStackTrace();
	}
        return null;
    }

    /**
     */
    public static void setProperty( Object o, String name ) {
	String setter= "set" +capitalize(name);
	try {
	    Method methods[]=findMethods( o.getClass() );
	    Method setPropertyMethod=null;
	    // find setFoo() method
	    for( int i=0; i< methods.length; i++ ) {
		Class paramT[]=methods[i].getParameterTypes();
		if( setter.equals( methods[i].getName() ) &&
		    paramT.length == 0 ) {
		    methods[i].invoke( o, new Object[] {} );
		    return;
		}
	    }
	} catch( Exception ex1 ) {
	    if( dbg > 0 )
		d("Exception for " + o.getClass() + " " + name);
	    if( dbg > 1 ) ex1.printStackTrace();
	}
    }

    /** Replace ${NAME} with the property value
     *  @deprecated Use the explicit method
     */
    public static String replaceProperties(String value,
					   Object getter )
    {
        if( getter instanceof Hashtable )
            return replaceProperties( value, (Hashtable)getter, null );

        if( getter instanceof PropertySource ) {
            PropertySource src[]=new PropertySource[] {(PropertySource)getter};
            return replaceProperties( value, null,  src);
        }
        return value;
    }

    /** Replace ${NAME} with the property value
     */
    public static String replaceProperties(String value,
					   Hashtable staticProp, PropertySource dynamicProp[] )
    {
        StringBuffer sb=new StringBuffer();
        int prev=0;
        // assert value!=nil
        int pos;
        while( (pos=value.indexOf( "$", prev )) >= 0 ) {
            if(pos>0) {
                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 to a Vector
     * <i>jars as file URLs (We use Vector for JDK 1.1 compat).
     *
     * @param jars A vector of URLs
     * @param cp a String classpath of directory or jar file
     *                    elements separated by path.separator delimiters.
     */
    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 void clear() {
        objectMethods.clear();
    }

    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 );
    }
}

Other Commons Modeler examples (source code examples)

Here is a short list of links related to this Commons Modeler IntrospectionUtils.java source code file:

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