lang/reflect/Field.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package java.lang.reflect;

import java.lang.annotation.Annotation;
import org.apache.harmony.kernel.vm.StringUtils;
import org.apache.harmony.luni.lang.reflect.GenericSignatureParser;
import org.apache.harmony.luni.lang.reflect.Types;

/**
 * This class represents a field. Information about the field can be accessed,
 * and the field's value can be accessed dynamically.
 */
public final class Field extends AccessibleObject implements Member {

    private Class<?> declaringClass;

    private Class<?> type;

    private Type genericType;

    private volatile boolean genericTypesAreInitialized = false;

    private String name;

    private int slot;

    private static final int TYPE_BOOLEAN = 1;

    private static final int TYPE_BYTE = 2;

    private static final int TYPE_CHAR = 3;

    private static final int TYPE_SHORT = 4;

    private static final int TYPE_INTEGER = 5;

    private static final int TYPE_FLOAT = 6;

    private static final int TYPE_LONG = 7;

    private static final int TYPE_DOUBLE = 8;

    /**
     * Construct a clone of the given instance.
     *
     * @param orig non-null; the original instance to clone
     */
    /*package*/ Field(Field orig) {
        this(orig.declaringClass, orig.type, orig.name, orig.slot);

        // Copy the accessible flag.
        if (orig.flag) {
            this.flag = true;
        }
    }

    private Field(Class<?> declaringClass, Class<?> type, String name, int slot) {
        this.declaringClass = declaringClass;
        this.type = type;
        this.name = name;
        this.slot = slot;
    }

    private synchronized void initGenericType() {
        if (!genericTypesAreInitialized) {
            String signatureAttribute = getSignatureAttribute();
            GenericSignatureParser parser = new GenericSignatureParser(
                    declaringClass.getClassLoader());
            parser.parseForField(this.declaringClass, signatureAttribute);
            genericType = parser.fieldType;
            if (genericType == null) {
                genericType = getType();
            }
            genericTypesAreInitialized = true;
        }
    }

    /** {@inheritDoc} */
    @Override
    /* package */String getSignatureAttribute() {
        Object[] annotation = getSignatureAnnotation(declaringClass, slot);

        if (annotation == null) {
            return null;
        }

        return StringUtils.combineStrings(annotation);
    }

    /**
     * Get the Signature annotation for this field. Returns null if not found.
     */
    native private Object[] getSignatureAnnotation(Class declaringClass, int slot);

    /**
     * Indicates whether or not this field is synthetic.
     *
     * @return {@code true} if this field is synthetic, {@code false} otherwise
     */
    public boolean isSynthetic() {
        int flags = getFieldModifiers(declaringClass, slot);
        return (flags & Modifier.SYNTHETIC) != 0;
    }

    /**
     * Returns the string representation of this field, including the field's
     * generic type.
     *
     * @return the string representation of this field
     */
    public String toGenericString() {
        StringBuilder sb = new StringBuilder(80);
        // append modifiers if any
        int modifier = getModifiers();
        if (modifier != 0) {
            sb.append(Modifier.toString(modifier)).append(' ');
        }
        // append generic type
        appendGenericType(sb, getGenericType());
        sb.append(' ');
        // append full field name
        sb.append(getDeclaringClass().getName()).append('.').append(getName());
        return sb.toString();
    }

    /**
     * Indicates whether or not this field is an enumeration constant.
     *
     * @return {@code true} if this field is an enumeration constant, {@code
     *         false} otherwise
     */
    public boolean isEnumConstant() {
        int flags = getFieldModifiers(declaringClass, slot);
        return (flags & Modifier.ENUM) != 0;
    }

    /**
     * Returns the generic type of this field.
     *
     * @return the generic type
     * @throws GenericSignatureFormatError
     *             if the generic field signature is invalid
     * @throws TypeNotPresentException
     *             if the generic type points to a missing type
     * @throws MalformedParameterizedTypeException
     *             if the generic type points to a type that cannot be
     *             instantiated for some reason
     */
    public Type getGenericType() {
        initGenericType();
        return Types.getType(genericType);
    }

    @Override
    public Annotation[] getDeclaredAnnotations() {
        return getDeclaredAnnotations(declaringClass, slot);
    }

    native private Annotation[] getDeclaredAnnotations(Class declaringClass, int slot);

    /**
     * Indicates whether or not the specified {@code object} is equal to this
     * field. To be equal, the specified object must be an instance of
     * {@code Field} with the same declaring class, type and name as this field.
     *
     * @param object
     *            the object to compare
     * @return {@code true} if the specified object is equal to this method,
     *         {@code false} otherwise
     * @see #hashCode
     */
    @Override
    public boolean equals(Object object) {
        return object instanceof Field && toString().equals(object.toString());
    }

    /**
     * Returns the value of the field in the specified object. This reproduces
     * the effect of {@code object.fieldName}
     *
     * <p>If the type of this field is a primitive type, the field value is
     * automatically boxed.
     *
     * <p>If this field is static, the object argument is ignored.
     * Otherwise, if the object is null, a NullPointerException is thrown. If
     * the object is not an instance of the declaring class of the method, an
     * IllegalArgumentException is thrown.
     *
     * <p>If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value, possibly boxed
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public Object get(Object object) throws IllegalAccessException, IllegalArgumentException {
        return getField(object, declaringClass, type, slot, flag);
    }

    /**
     * Returns the value of the field in the specified object as a {@code
     * boolean}. This reproduces the effect of {@code object.fieldName}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public boolean getBoolean(Object object) throws IllegalAccessException,
            IllegalArgumentException {
        return getZField(object, declaringClass, type, slot, flag, TYPE_BOOLEAN);
    }

    /**
     * Returns the value of the field in the specified object as a {@code byte}.
     * This reproduces the effect of {@code object.fieldName}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public byte getByte(Object object) throws IllegalAccessException, IllegalArgumentException {
        return getBField(object, declaringClass, type, slot, flag, TYPE_BYTE);
    }

    /**
     * Returns the value of the field in the specified object as a {@code char}.
     * This reproduces the effect of {@code object.fieldName}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public char getChar(Object object) throws IllegalAccessException, IllegalArgumentException {
        return getCField(object, declaringClass, type, slot, flag, TYPE_CHAR);
    }

    /**
     * Returns the class that declares this field.
     *
     * @return the declaring class
     */
    public Class<?> getDeclaringClass() {
        return declaringClass;
    }

    /**
     * Returns the value of the field in the specified object as a {@code
     * double}. This reproduces the effect of {@code object.fieldName}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public double getDouble(Object object) throws IllegalAccessException, IllegalArgumentException {
        return getDField(object, declaringClass, type, slot, flag, TYPE_DOUBLE);
    }

    /**
     * Returns the value of the field in the specified object as a {@code float}
     * . This reproduces the effect of {@code object.fieldName}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public float getFloat(Object object) throws IllegalAccessException, IllegalArgumentException {
        return getFField(object, declaringClass, type, slot, flag, TYPE_FLOAT);
    }

    /**
     * Returns the value of the field in the specified object as an {@code int}.
     * This reproduces the effect of {@code object.fieldName}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public int getInt(Object object) throws IllegalAccessException, IllegalArgumentException {
        return getIField(object, declaringClass, type, slot, flag, TYPE_INTEGER);
    }

    /**
     * Returns the value of the field in the specified object as a {@code long}.
     * This reproduces the effect of {@code object.fieldName}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public long getLong(Object object) throws IllegalAccessException, IllegalArgumentException {
        return getJField(object, declaringClass, type, slot, flag, TYPE_LONG);
    }

    /**
     * Returns the modifiers for this field. The {@link Modifier} class should
     * be used to decode the result.
     *
     * @return the modifiers for this field
     * @see Modifier
     */
    public int getModifiers() {
        return getFieldModifiers(declaringClass, slot);
    }

    private native int getFieldModifiers(Class<?> declaringClass, int slot);

    /**
     * Returns the name of this field.
     *
     * @return the name of this field
     */
    public String getName() {
        return name;
    }

    /**
     * Returns the value of the field in the specified object as a {@code short}
     * . This reproduces the effect of {@code object.fieldName}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * @param object
     *            the object to access
     * @return the field value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public short getShort(Object object) throws IllegalAccessException, IllegalArgumentException {
        return getSField(object, declaringClass, type, slot, flag, TYPE_SHORT);
    }

    /**
     * Returns the constructor's signature in non-printable form. This is called
     * (only) from IO native code and needed for deriving the serialVersionUID
     * of the class
     *
     * @return the constructor's signature.
     */
    @SuppressWarnings("unused")
    private String getSignature() {
        return getSignature(type);
    }

    /**
     * Return the {@link Class} associated with the type of this field.
     *
     * @return the type of this field
     */
    public Class<?> getType() {
        return type;
    }

    /**
     * Returns an integer hash code for this field. Objects which are equal
     * return the same value for this method.
     * <p>
     * The hash code for a Field is the exclusive-or combination of the hash
     * code of the field's name and the hash code of the name of its declaring
     * class.
     *
     * @return the hash code for this field
     * @see #equals
     */
    @Override
    public int hashCode() {
        return name.hashCode() ^ getDeclaringClass().getName().hashCode();
    }

    /**
     * Sets the value of the field in the specified object to the value. This
     * reproduces the effect of {@code object.fieldName = value}
     *
     * <p>If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     *
     * <p>If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     *
     * <p>If the field type is a primitive type, the value is automatically
     * unboxed. If the unboxing fails, an IllegalArgumentException is thrown. If
     * the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void set(Object object, Object value) throws IllegalAccessException,
            IllegalArgumentException {
        setField(object, declaringClass, type, slot, flag, value);
    }

    /**
     * Sets the value of the field in the specified object to the {@code
     * boolean} value. This reproduces the effect of {@code object.fieldName =
     * value}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     * <p>
     * If the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void setBoolean(Object object, boolean value) throws IllegalAccessException,
            IllegalArgumentException {
        setZField(object, declaringClass, type, slot, flag, TYPE_BOOLEAN, value);
    }

    /**
     * Sets the value of the field in the specified object to the {@code byte}
     * value. This reproduces the effect of {@code object.fieldName = value}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     * <p>
     * If the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void setByte(Object object, byte value) throws IllegalAccessException,
            IllegalArgumentException {
        setBField(object, declaringClass, type, slot, flag, TYPE_BYTE, value);
    }

    /**
     * Sets the value of the field in the specified object to the {@code char}
     * value. This reproduces the effect of {@code object.fieldName = value}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     * <p>
     * If the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void setChar(Object object, char value) throws IllegalAccessException,
            IllegalArgumentException {
        setCField(object, declaringClass, type, slot, flag, TYPE_CHAR, value);
    }

    /**
     * Sets the value of the field in the specified object to the {@code double}
     * value. This reproduces the effect of {@code object.fieldName = value}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     * <p>
     * If the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void setDouble(Object object, double value) throws IllegalAccessException,
            IllegalArgumentException {
        setDField(object, declaringClass, type, slot, flag, TYPE_DOUBLE, value);
    }

    /**
     * Sets the value of the field in the specified object to the {@code float}
     * value. This reproduces the effect of {@code object.fieldName = value}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     * <p>
     * If the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void setFloat(Object object, float value) throws IllegalAccessException,
            IllegalArgumentException {
        setFField(object, declaringClass, type, slot, flag, TYPE_FLOAT, value);
    }

    /**
     * Set the value of the field in the specified object to the {@code int}
     * value. This reproduces the effect of {@code object.fieldName = value}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     * <p>
     * If the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void setInt(Object object, int value) throws IllegalAccessException,
            IllegalArgumentException {
        setIField(object, declaringClass, type, slot, flag, TYPE_INTEGER, value);
    }

    /**
     * Sets the value of the field in the specified object to the {@code long}
     * value. This reproduces the effect of {@code object.fieldName = value}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     * <p>
     * If the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void setLong(Object object, long value) throws IllegalAccessException,
            IllegalArgumentException {
        setJField(object, declaringClass, type, slot, flag, TYPE_LONG, value);
    }

    /**
     * Sets the value of the field in the specified object to the {@code short}
     * value. This reproduces the effect of {@code object.fieldName = value}
     * <p>
     * If this field is static, the object argument is ignored.
     * Otherwise, if the object is {@code null}, a NullPointerException is
     * thrown. If the object is not an instance of the declaring class of the
     * method, an IllegalArgumentException is thrown.
     * <p>
     * If this Field object is enforcing access control (see AccessibleObject)
     * and this field is not accessible from the current context, an
     * IllegalAccessException is thrown.
     * <p>
     * If the value cannot be converted to the field type via a widening
     * conversion, an IllegalArgumentException is thrown.
     *
     * @param object
     *            the object to access
     * @param value
     *            the new value
     * @throws NullPointerException
     *             if the object is {@code null} and the field is non-static
     * @throws IllegalArgumentException
     *             if the object is not compatible with the declaring class
     * @throws IllegalAccessException
     *             if this field is not accessible
     */
    public void setShort(Object object, short value) throws IllegalAccessException,
            IllegalArgumentException {
        setSField(object, declaringClass, type, slot, flag, TYPE_SHORT, value);
    }

    /**
     * Returns a string containing a concise, human-readable description of this
     * field.
     * <p>
     * The format of the string is:
     * <ol>
     *   <li>modifiers (if any)
     *   <li>type
     *   <li>declaring class name
     *   <li>'.'
     *   <li>field name
     * </ol>
     * <p>
     * For example: {@code public static java.io.InputStream
     * java.lang.System.in}
     *
     * @return a printable representation for this field
     */
    @Override
    public String toString() {
        StringBuilder result = new StringBuilder(Modifier.toString(getModifiers()));
        if (result.length() != 0) {
            result.append(' ');
        }
        appendArrayType(result, type);
        result.append(' ');
        result.append(declaringClass.getName());
        result.append('.');
        result.append(name);
        return result.toString();
    }

    private native Object getField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck) throws IllegalAccessException;

    private native double getDField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no) throws IllegalAccessException;

    private native int getIField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no) throws IllegalAccessException;

    private native long getJField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no) throws IllegalAccessException;

    private native boolean getZField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no) throws IllegalAccessException;

    private native float getFField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no) throws IllegalAccessException;

    private native char getCField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no) throws IllegalAccessException;

    private native short getSField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no) throws IllegalAccessException;

    private native byte getBField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no) throws IllegalAccessException;

    private native void setField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, Object value) throws IllegalAccessException;

    private native void setDField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no, double v) throws IllegalAccessException;

    private native void setIField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no, int i) throws IllegalAccessException;

    private native void setJField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no, long j) throws IllegalAccessException;

    private native void setZField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no, boolean z) throws IllegalAccessException;

    private native void setFField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no, float f) throws IllegalAccessException;

    private native void setCField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no, char c) throws IllegalAccessException;

    private native void setSField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no, short s) throws IllegalAccessException;

    private native void setBField(Object o, Class<?> declaringClass, Class<?> type, int slot,
            boolean noAccessCheck, int type_no, byte b) throws IllegalAccessException;

}