Java Reflection Field Set setField(Field f, Object this_, Object value)

Description

Sets field with specified value in spite of access permission.

License

Open Source License

Exception

Parameter	Description
AssertionError	if field is final

Declaration

public static void setField(Field f, Object this_, Object value) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.lang.reflect.Field;

public class Main {
    /**//from  ww w.  j a va2 s . c  om
     * Sets field with specified value in spite of access permission.
     *
     * @throws AssertionError if field is final
     */
    public static void setField(Field f, Object this_, Object value) {
        try {
            f.setAccessible(true);
            f.set(this_, value);
        } catch (IllegalAccessException e) {
            throw new AssertionError(e);
        }
    }

    /**
     * Sets field with specified value in spite of access permission.
     *
     * @throws AssertionError if no such field in the class or field is final
     */
    public static void setField(Class<?> clazz, String fname, Object this_, Object value,
            boolean isSearchSuperclass) {
        try {
            Field f = findField(clazz, fname, isSearchSuperclass);
            setField(f, this_, value);
        } catch (NoSuchFieldException e) {
            throw new AssertionError(e);
        }
    }

    private static Field findField(Class<?> clazz, String fname, boolean isSearchSuperclass)
            throws NoSuchFieldException, AssertionError {
        Field f = null;
        try {
            f = clazz.getDeclaredField(fname);
        } catch (NoSuchFieldException e) {

        }
        if (f == null && isSearchSuperclass) {
            do {
                clazz = clazz.getSuperclass();
                if (clazz == null) {
                    throw new NoSuchFieldException("Class " + clazz + " has no such field: %s" + fname); //$NON-NLS-1$ //$NON-NLS-2$
                }
                try {
                    f = clazz.getDeclaredField(fname);
                } catch (NoSuchFieldException e) {

                }
            } while (f == null);
        }
        return f;
    }

    public static Object getDeclaredField(String name, Object this_) {
        try {
            Field field = this_.getClass().getDeclaredField(name);
            field.setAccessible(true);
            return getField(field, this_);
        } catch (SecurityException e) {
            throw new AssertionError(e);
        } catch (NoSuchFieldException e) {
            throw new AssertionError(e);
        }
    }

    /**
     * Gets value of field in spite of access permission.
     */
    public static Object getField(Field f, Object this_) {
        try {
            f.setAccessible(true);
            return f.get(this_);
        } catch (IllegalAccessException e) {
            throw new AssertionError(e);
        }
    }

    /**
     * Gets value of field in spite of access permission.
     *
     * @throws AssertionError if no such field in the class
     */
    public static Object getField(Class<?> clazz, String fname, Object this_, boolean isSearchSuperclass) {
        try {
            Field f = findField(clazz, fname, isSearchSuperclass);
            return getField(f, this_);
        } catch (NoSuchFieldException e) {
            throw new AssertionError(e);
        }
    }
}

Related

1. setField(Class ownerClass, Object owner, String fieldName, Object newValue)
2. setField(Class target, Class fieldType, int index, Object obj, Object value)
3. setField(Class clazz, T instance, String fieldName, Object value)
4. setField(Class clazz, T instance, String fieldName, Object value)
5. setField(Field f, Object instance, Object value)
6. setField(Field field, @Nullable Object instance, Object thing)
7. setField(Field field, Object classWithField, Object value)
8. setField(Field field, Object instance, Object value)
9. setField(Field field, Object obj, String value)