Java Reflection Field Value Set setFieldValue(Object object, String fieldName, Object value)

Description

Sets the value of a field in an object.

License

Apache License

Parameter

Parameter	Description
object	Object in which to set the field.
fieldName	Name of the field.
value	Value to which to set the field.

Declaration

public static void setFieldValue(Object object, String fieldName, Object value) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.lang.reflect.Field;

import java.util.ArrayList;
import java.util.Arrays;

import java.util.List;

public class Main {
    /**/*from   w w w . j a va 2s . c o m*/
     * Sets the value of a field in an object.
     *
     * @param object
     *            Object in which to set the field.
     * @param fieldName
     *            Name of the field.
     * @param value
     *            Value to which to set the field.
     */
    public static void setFieldValue(Object object, String fieldName, Object value) {
        try {
            Field field = getDeclaredFieldInHierarchy(object.getClass(), fieldName);
            if (field == null) {
                throw new RuntimeException(String.format("Class %s does not have field %s in its hierarchy.",
                        object.getClass(), fieldName));
            }
            field.setAccessible(true);
            field.set(object, value);
        } catch (Exception ex) {
            if (ex instanceof RuntimeException) {
                throw (RuntimeException) ex;
            } else {
                throw new RuntimeException(ex);
            }
        }

    }

    /**
     * Returns the field with the given name in the class hierarchy. If multiple
     * fields with the same name exist in hierarchy, the field in the class
     * closest to the clazz gets returned.
     *
     * @param clazz
     *            class to look for fields in the hierarchy
     * @param fieldName
     *            fieldName to find in the class
     */
    public static Field getDeclaredFieldInHierarchy(Class<?> clazz, String fieldName) {
        assert fieldName != null : "fieldName cannot be null";
        Field[] fields = getDeclaredFieldsInHierarchy(clazz);
        for (Field field : fields) {
            if (fieldName.equals(field.getName())) {
                return field;
            }
        }
        return null;
    }

    /**
     * Returns an array of all declared fields in the given class and all
     * super-classes.
     */
    public static Field[] getDeclaredFieldsInHierarchy(Class<?> clazz) {

        if (clazz.isPrimitive()) {
            throw new IllegalArgumentException("Primitive types not supported.");
        }

        List<Field> result = new ArrayList<Field>();

        while (true) {

            if (clazz == Object.class) {
                break;
            }

            result.addAll(Arrays.asList(clazz.getDeclaredFields()));
            clazz = clazz.getSuperclass();
        }

        return result.toArray(new Field[result.size()]);
    }
}

Related

1. setFieldValue(Object object, String fieldName, Object fieldValue)
2. setFieldValue(Object object, String fieldName, Object fieldValue)
3. setFieldValue(Object object, String fieldName, Object fieldValue)
4. setFieldValue(Object object, String fieldName, Object value)
5. setFieldValue(Object object, String fieldName, Object value)
6. setFieldValue(Object object, String fieldName, Object value)
7. setFieldValue(Object object, String name, Object value)
8. setFieldValue(Object object, String name, Object value)
9. setFieldValue(Object objectInstance, String fieldName, Object valueToSet)