com.robonobo.common.util.BeanPropertyAccessor.java Source code

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Here is the source code for com.robonobo.common.util.BeanPropertyAccessor.java

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package com.robonobo.common.util;
/*
 * Robonobo Common Utils
 * Copyright (C) 2008 Will Morton (macavity@well.com) & Ray Hilton (ray@wirestorm.net)
    
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
    
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
    
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class BeanPropertyAccessor {
    Object o;
    Log log = LogFactory.getLog(getClass());

    public BeanPropertyAccessor(Object o) {
        this.o = o;
    }

    /**
     * Attempts to copy properties from the object from to object to
     * @param from
     * @param to
     */
    public static void copy(Object from, Object to) throws Exception {
        BeanPropertyAccessor fromAccessor = new BeanPropertyAccessor(from);
        BeanPropertyAccessor toAccessor = new BeanPropertyAccessor(to);
        Iterator i = fromAccessor.getPropertyNames().iterator();
        while (i.hasNext()) {
            String property = (String) i.next();
            Method m = fromAccessor.getGetterMethod(property);
            if (fromAccessor.getProperty(property) != null) {
                toAccessor.setProperty(property, m.getReturnType(), fromAccessor.getProperty(property));
            }
        }

    }

    public Collection getPropertyNames() {
        List methodNames = new Vector();
        Method[] methods = o.getClass().getMethods();
        for (int i = 0; i < methods.length; i++) {
            if (methods[i].getName().startsWith("set") && methods[i].getParameterTypes().length == 1) {
                String name = getName(methods[i]);
                methodNames.add(name);

                // descend down hierachy
                try {
                    Method m = getGetterMethod(name);
                    Object obj = m.invoke(this.o, new Object[] {});
                    if (obj != null) {
                        Iterator j = new BeanPropertyAccessor(obj).getPropertyNames().iterator();
                        while (j.hasNext()) {
                            String subName = (String) j.next();
                            methodNames.add(name + "." + subName);
                        }
                    }
                } catch (NoSuchMethodException e) {
                    // do nothing, no such method
                } catch (Exception e) {
                    log.error("Cannot invoke getter methd", e);
                }
            }
        }
        return methodNames;
    }

    public void setProperty(String name, Object value) throws Exception {
        setProperty(name, value.getClass(), value);
    }

    public void setProperty(String name, int value) throws Exception {
        setProperty(name, int.class, new Integer(value));
    }

    public void setProperty(String name, boolean value) throws Exception {
        setProperty(name, boolean.class, new Boolean(value));
    }

    public void setProperty(String name, float value) throws Exception {
        setProperty(name, float.class, new Float(value));
    }

    public Object getProperty(String name) throws Exception {
        String[] bits = name.split("\\.", 2);
        Method m = getGetterMethod(bits[0]);
        Object rtn = m.invoke(o, new Object[] {});

        if (bits.length == 1)
            return rtn;
        else
            return new BeanPropertyAccessor(rtn).getProperty(bits[1]);
    }

    protected void setProperty(String name, Class cl, Object value) throws Exception {
        String[] bits = name.split("\\.", 2);

        if (bits.length == 1) {
            Method m = getSetterMethod(bits[0], cl);
            m.invoke(o, new Object[] { value });
        } else {
            new BeanPropertyAccessor(getProperty(bits[0])).setProperty(bits[1], cl, value);
        }
    }

    protected String getName(Method m) {
        return m.getName().substring(3, 4).toLowerCase() + m.getName().substring(4);
    }

    protected String getSetterMethodName(String name) {
        return "set" + name.substring(0, 1).toUpperCase() + name.substring(1);
    }

    protected Method getSetterMethod(String name, Class cl) throws NoSuchMethodException {
        String method = getSetterMethodName(name);
        return o.getClass().getMethod(method, new Class[] { cl });
    }

    //   protected String getGetterMethodName(String name) {
    //      return "get" + name.substring(0,1).toUpperCase() + name.substring(1);
    //   }

    protected Method getGetterMethod(String name) throws NoSuchMethodException {
        String[] nominations = new String[] { "get" + name.substring(0, 1).toUpperCase() + name.substring(1),
                "is" + name.substring(0, 1).toUpperCase() + name.substring(1) };
        for (int i = 0; i < nominations.length; i++) {
            try {
                String method = nominations[i];
                return o.getClass().getMethod(method, new Class[] {});
            } catch (NoSuchMethodException e) {
                // nope. couldnt find it
            }
        }
        throw new NoSuchMethodException("Tried to find methods " + nominations + " but failed");
    }
}