elsupport.java

java属性邦定的（JSR-295）的一个实现

/*
 * Copyright (C) 2007 Sun Microsystems, Inc. All rights reserved. Use is
 * subject to license terms.
 */

package org.jdesktop.el.impl.lang;

import java.beans.PropertyEditor;
import java.beans.PropertyEditorManager;
import java.math.BigDecimal;
import java.math.BigInteger;

import org.jdesktop.el.ELException;
import org.jdesktop.el.PropertyNotFoundException;

import org.jdesktop.el.impl.util.MessageFactory;

/**
 * A helper class that implements the EL Specification
 * 
 * @author Jacob Hookom [[e-mail]]
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: kchung $
 */
public class ELSupport {

    private final static ELSupport REF = new ELSupport();

    private final static Long ZERO = new Long(0L);

    public final static void throwUnhandled(Object base, Object property)
            throws ELException {
        if (base == null) {
            throw new PropertyNotFoundException(MessageFactory.get(
                    "error.resolver.unhandled.null", property));
        } else {
            throw new PropertyNotFoundException(MessageFactory.get(
                    "error.resolver.unhandled", base.getClass(), property));
        }
    }

    /**
     * @param obj0
     * @param obj1
     * @return
     * @throws EvaluationException
     */
    public final static int compare(final Object obj0, final Object obj1)
            throws ELException {
        if (obj0 == obj1 || equals(obj0, obj1)) {
            return 0;
        }
        if (isBigDecimalOp(obj0, obj1)) {
            BigDecimal bd0 = (BigDecimal) coerceToNumber(obj0, BigDecimal.class);
            BigDecimal bd1 = (BigDecimal) coerceToNumber(obj1, BigDecimal.class);
            return bd0.compareTo(bd1);
        }
        if (isDoubleOp(obj0, obj1)) {
            Double d0 = (Double) coerceToNumber(obj0, Double.class);
            Double d1 = (Double) coerceToNumber(obj1, Double.class);
            return d0.compareTo(d1);
        }
        if (isBigIntegerOp(obj0, obj1)) {
            BigInteger bi0 = (BigInteger) coerceToNumber(obj0, BigInteger.class);
            BigInteger bi1 = (BigInteger) coerceToNumber(obj1, BigInteger.class);
            return bi0.compareTo(bi1);
        }
        if (isLongOp(obj0, obj1)) {
            Long l0 = (Long) coerceToNumber(obj0, Long.class);
            Long l1 = (Long) coerceToNumber(obj1, Long.class);
            return l0.compareTo(l1);
        }
        if (obj0 instanceof String || obj1 instanceof String) {
            return coerceToString(obj0).compareTo(coerceToString(obj1));
        }
        if (obj0 instanceof Comparable) {
            return (obj1 != null) ? ((Comparable) obj0).compareTo(obj1) : 1;
        }
        if (obj1 instanceof Comparable) {
            return (obj0 != null) ? -((Comparable) obj1).compareTo(obj0) : -1;
        }
        throw new ELException(MessageFactory.get("error.compare", obj0, obj1));
    }

    /**
     * @param obj0
     * @param obj1
     * @return
     * @throws EvaluationException
     */
    public final static boolean equals(final Object obj0, final Object obj1)
            throws ELException {
        if (obj0 == obj1) {
            return true;
        }
        if (obj0 == null || obj1 == null) {
            return false;
        }
        if (obj0 instanceof Boolean || obj1 instanceof Boolean) {
            return coerceToBoolean(obj0).equals(coerceToBoolean(obj1));
        }
        if (obj0.getClass().isEnum()) {
            return obj0.equals(coerceToEnum(obj1, obj0.getClass()));
        }
        if (obj1.getClass().isEnum()) {
            return obj1.equals(coerceToEnum(obj0, obj1.getClass()));
        }
        if (obj0 instanceof String || obj1 instanceof String) {
            return coerceToString(obj0).equals(coerceToString(obj1));
        }
        if (isBigDecimalOp(obj0, obj1)) {
            BigDecimal bd0 = (BigDecimal) coerceToNumber(obj0, BigDecimal.class);
            BigDecimal bd1 = (BigDecimal) coerceToNumber(obj1, BigDecimal.class);
            return bd0.equals(bd1);
        }
        if (isDoubleOp(obj0, obj1)) {
            Double d0 = (Double) coerceToNumber(obj0, Double.class);
            Double d1 = (Double) coerceToNumber(obj1, Double.class);
            return d0.equals(d1);
        }
        if (isBigIntegerOp(obj0, obj1)) {
            BigInteger bi0 = (BigInteger) coerceToNumber(obj0, BigInteger.class);
            BigInteger bi1 = (BigInteger) coerceToNumber(obj1, BigInteger.class);
            return bi0.equals(bi1);
        }
        if (isLongOp(obj0, obj1)) {
            Long l0 = (Long) coerceToNumber(obj0, Long.class);
            Long l1 = (Long) coerceToNumber(obj1, Long.class);
            return l0.equals(l1);
        } else {
            return obj0.equals(obj1);
        }
    }

    /**
     * @param obj
     * @return
     */
    public final static Boolean coerceToBoolean(final Object obj)
            throws IllegalArgumentException {
        if (obj == null || "".equals(obj)) {
            return Boolean.FALSE;
        }
        if (obj instanceof Boolean || obj.getClass() == Boolean.TYPE) {
            return (Boolean) obj;
        }
        if (obj instanceof String) {
            return Boolean.valueOf((String) obj);
        }

        throw new IllegalArgumentException(MessageFactory.get("error.convert",
                obj, obj.getClass(), Boolean.class));
    }

    public final static Enum coerceToEnum(final Object obj, Class type)
            throws IllegalArgumentException {
        if (obj == null || "".equals(obj)) {
            return null;
        }
        if (type.isInstance(obj)) {
            return (Enum)obj;
        }
        if (obj instanceof String) {
            return Enum.valueOf(type, (String) obj);
        }

        throw new IllegalArgumentException(MessageFactory.get("error.convert",
                obj, obj.getClass(), type));
    }

    public final static Character coerceToCharacter(final Object obj)
            throws IllegalArgumentException {
        if (obj == null || "".equals(obj)) {
            return new Character((char) 0);
        }
        if (obj instanceof String) {
            return new Character(((String) obj).charAt(0));
        }
        if (ELArithmetic.isNumber(obj)) {
            return new Character((char) ((Number) obj).shortValue());
        }
        Class objType = obj.getClass();
        if (obj instanceof Character || objType == Character.TYPE) {
            return (Character) obj;
        }

        throw new IllegalArgumentException(MessageFactory.get("error.convert",
                obj, objType, Character.class));
    }

    public final static Number coerceToNumber(final Object obj) {
        if (obj == null) {
            return ZERO;
        } else if (obj instanceof Number) {
            return (Number) obj;
        } else {
            String str = coerceToString(obj);
            if (isStringFloat(str)) {
                return toFloat(str);
            } else {
                return toNumber(str);
            }
        }
    }

    protected final static Number coerceToNumber(final Number number,
            final Class type) throws IllegalArgumentException {
        if (Long.TYPE == type || Long.class.equals(type)) {
            return new Long(number.longValue());
        }
        if (Double.TYPE == type || Double.class.equals(type)) {
            return new Double(number.doubleValue());
        }
        if (Integer.TYPE == type || Integer.class.equals(type)) {
            return new Integer(number.intValue());
        }
        if (BigInteger.class.equals(type)) {
            if (number instanceof BigDecimal) {
                return ((BigDecimal) number).toBigInteger();
            }
            return BigInteger.valueOf(number.longValue());
        }
        if (BigDecimal.class.equals(type)) {
            if (number instanceof BigInteger) {
                return new BigDecimal((BigInteger) number);
            }
//            return new BigDecimal(number.toString());
            return new BigDecimal(number.doubleValue());
        }
        if (Byte.TYPE == type || Byte.class.equals(type)) {
            return new Byte(number.byteValue());
        }
        if (Short.TYPE == type || Short.class.equals(type)) {