Java Reflection Field Find findFieldsOfClass(Class target, Object o, String path, Logger log, Set done)

Description

find Fields Of Class

License

Open Source License

Declaration

public static void findFieldsOfClass(Class target, Object o, String path, Logger log, Set done) 

Method Source Code

//package com.java2s;
/*//w w w .j  a v  a  2  s .  com
 *   $Id$
 *
 *   Copyright 2006 University of Dundee. All rights reserved.
 *   Use is subject to license terms supplied in LICENSE.txt
 */

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.slf4j.Logger;

public class Main {
    public static void findFieldsOfClass(Class target, Object o, String path, Logger log, Set done) {
        if (null == path || path.equals("")) {
            path = "\nthis";
        }
        if (null == done) {
            done = new HashSet();
        }
        if (done.contains(o)) {
            return;
        }
        done.add(o);

        if (target.isInstance(o)) {
            log.info(path + ";" + "\n----------------------\n" + o.toString() + " < " + o.getClass());
        } else if (o instanceof Set) {
            for (Iterator it = ((Set) o).iterator(); it.hasNext();) {
                Object element = it.next();
                findFieldsOfClass(target, element, path, log, done);
            }
        } else {
            Method[] accessors = getGettersAndSetters(o);
            log.debug(accessors.toString()); // slf4j migration: toString()
            for (int i = 0; i < accessors.length; i++) {
                Method method = accessors[i];
                if (method.getName().startsWith("get")) {
                    log.debug("Trying " + method);
                    Object obj = invokeGetter(o, method);
                    if (null != obj) {
                        findFieldsOfClass(target, obj, path + ".\n" + method.getName() + "()", log, done);
                    }
                }
            }
        }
    }

    public static Method[] getGettersAndSetters(Object obj) {
        Method[] methods, superMethods = null;
        methods = obj.getClass().getDeclaredMethods();
        Package pkg = obj.getClass().getPackage();
        if (null != pkg && pkg.toString().indexOf("ome.model2") > -1) {// FIXME
                                                                       // not
                                                                       // valid
            superMethods = obj.getClass().getSuperclass().getDeclaredMethods();
        }
        List goodMethods = checkGettersAndSetters(methods);
        goodMethods.addAll(checkGettersAndSetters(superMethods));
        return (Method[]) goodMethods.toArray(new Method[goodMethods.size()]);
    }

    /**
     * call getter and return object.
     * 
     * @DEV.TODO there maybe be cases where an exception is ok
     * @param target
     *            object on which to call getter
     * @param getter
     *            method for some field
     * @return value stored in field
     */
    public static Object invokeGetter(Object target, Method getter) {
        RuntimeException re = new RuntimeException("Error trying to get value: " + getter.toString());
        Object result = null;
        try {
            result = getter.invoke(target, new Object[] {});
        } catch (IllegalArgumentException e) {
            re.initCause(e);
            throw re;
        } catch (IllegalAccessException e) {
            re.initCause(e);
            throw re;
        } catch (InvocationTargetException e) {
            re.initCause(e);
            throw re;
        }
        return result;
    }

    static List checkGettersAndSetters(Method[] methods) {
        List goodMethods = new ArrayList();

        if (null == methods) {
            return goodMethods;
        }

        for (int i = 0; i < methods.length; i++) {
            boolean ok = true;
            Method method = methods[i];
            int mod = method.getModifiers();
            if (!Modifier.isPublic(mod) || Modifier.isStatic(mod)) {
                ok = false;
            }

            if (method.getName().startsWith("get")) {
                if (0 != method.getParameterTypes().length) {
                    ok = false;
                }
            } else if (method.getName().startsWith("set")) {
                // No constaints yet on setters.
            } else {
                ok = false;
            }

            if (ok) {
                goodMethods.add(method);
            }
        }
        return goodMethods;
    }
}

Related

1. findFields(Class c, boolean allowTransient, int max, Iterable> fieldClassesToFind, Iterable> exceptClasses)
2. findFields(Class type)
3. findFields(final Class clazz, final Predicate filter)
4. findFieldsAnnotatedWith(Class annotation, Class parentClass)
5. findFieldsAnnotatedWith(final Class type, final Class annotation)
6. findFieldToInject(Class target, String name, Class source)
7. findFieldType(Field field, Class concreteClass)
8. findFieldWithAnnotation(String fieldName, Class clazz, Class annotationType)