Sets a member to a value using a setter method, or if none found, using member access if the member is public

Description

Demo Code

/**//w w  w.jav  a 2 s.  c  o m
 * Copyright (c) 2003-2009, Xith3D Project Group all rights reserved.
 * 
 * Portions based on the Java3D interface, Copyright by Sun Microsystems.
 * Many thanks to the developers of Java3D and Sun Microsystems for their
 * innovation and design.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the 'Xith3D Project Group' nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) A
 * RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE
 */
import java.lang.reflect.Method;

public class Main{
    public static void main(String[] argv) throws Exception{
        Object object = "java2s.com";
        String member = "java2s.com";
        Object value = "java2s.com";
        set(object,member,value);
    }
    /**
     * Sets a member to a value using a setter method, or if none found,
     * using member access if the member is public
     * 
     * @param object
     *                The object of which to set the member
     * @param member
     *                The member to change
     * @param value
     *                The value to set the member to
     */
    public static void set(Object object, String member, Object value) {

        try {

            // try to find a setter
            Method met = getSetter(object, member);
            try {
                met.invoke(object, new Object[] { value });
            } catch (Exception e) {
                throw new Error(e);
            }

        } catch (NoSetterException e) {

            try {
                // try to set it via member access
                object.getClass().getField(member).set(object, value);
            } catch (NoSuchFieldException ex) {
                throw new Error("Couldn't find setter nor member of name "
                        + member + " in object of type : "
                        + object.getClass().getSimpleName());
            } catch (Exception ex) {
                throw new Error(ex);
            }

        }

    }
    /**
     * Finds the appropriate setter for the member of an object.
     * 
     * @param object The object
     * @param member Its member
     * @return The setter
     * @throws NoSetterException if no setter can be found
     */
    public static Method getSetter(Object object, String member)
            throws NoSetterException {

        StringBuffer buffer = new StringBuffer(member.length() + 4);
        buffer.append("set");
        buffer.append(member.substring(0, 1).toUpperCase());
        buffer.append(member.substring(1));
        String name = buffer.toString();

        Method met = null;

        try {
            // First try to get the most evident method, getMethod(memberType);
            Class<?> clazz = object.getClass().getDeclaredField(member)
                    .getType();
            // Try to find the method
            met = object.getClass().getMethod(name, new Class[] { clazz });
        } catch (Exception e) {
            // Didn't work ? Well, let's try another way..
            Method[] methods = object.getClass().getMethods();
            search: for (Method potentialMethod : methods) {
                // If right method and only one parameter, we found it !!
                if (potentialMethod.getName().equals(name)
                        && potentialMethod.getParameterTypes().length == 1) {
                    met = potentialMethod;
                    break search;
                }
            }
        }

        if (met == null) {
            throw new NoSetterException(
                    "Could not find a setter for member " + member
                            + " of object of type "
                            + object.getClass().getSimpleName());
        }

        return met;

    }
}
Sets a member to a value using a setter method, or if none found, using member access if the member is public - Java Reflection

Description

Demo Code

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