introspectionutils.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 *  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.catalina.tribes.demos;

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
 */
public final class IntrospectionUtils {


    private static org.apache.commons.logging.Log log=
        org.apache.commons.logging.LogFactory.getLog( IntrospectionUtils.class );

    /**
     * Call execute() - any ant-like task should work
     */
    public static void execute(Object proxy, String method) throws Exception {
        Method executeM = null;
        Class c = proxy.getClass();
        Class params[] = new Class[0];
        //	params[0]=args.getClass();
        executeM = findMethod(c, method, params);
        if (executeM == null) {
            throw new RuntimeException("No execute in " + proxy.getClass());
        }
        executeM.invoke(proxy, (Object[]) null);//new Object[] { args });
    }

    /**
     * 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();
        Class params[] = new Class[2];
        params[0] = String.class;
        params[1] = Object.class;
        executeM = findMethod(c, "setAttribute", params);
        if (executeM == null) {
            if (log.isDebugEnabled())
                log.debug("No setAttribute in " + proxy.getClass());
            return;
        }
        if (false)
            if (log.isDebugEnabled())
                log.debug("Setting " + n + "=" + v + "  in " + proxy);
        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();
        Class params[] = new Class[1];
        params[0] = String.class;
        executeM = findMethod(c, "getAttribute", params);
        if (executeM == null) {
            if (log.isDebugEnabled())
                log.debug("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) {
        if (log.isDebugEnabled()) {
            log.debug(msg);
            for (int i = 0; i < cp.length; i++) {
                log.debug(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 ( long )
                    }else if ("java.lang.Long".equals(paramType.getName())
                                || "long".equals(paramType.getName())) {
                            try {
                                params[0] = new Long(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;
                        }

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

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

                // save "setProperty" for later