/* Primitives.java
Purpose:
Description:
History:
2002/3/25, Henri Chen: Created.
2003/4/17, Tom M. Yeh: Moves primitive relevant utilities from Classes
Copyright (C) 2001 Potix Corporation. All Rights Reserved.
{{IS_RIGHT
This program is distributed under LGPL Version 3.0 in the hope that
it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.lang;
import java.util.Map;
import java.util.HashMap;
/**
* Utilities regarding primitive type and its wrapper class.
*
* @author henrichen
*/
public class Primitives {
/**
* Convert Boolean object to primitive boolean.
*/
public static final boolean toPrimitive(Boolean obj) {
return obj.booleanValue();
}
/**
* Convert primitive boolean to Boolean.
*/
public static final Boolean toWrapper(boolean obj) {
return Boolean.valueOf(obj);
}
/**
* Convert Byte object to primitive byte.
*/
public static final byte toPrimitive(Byte obj) {
return obj.byteValue();
}
/**
* Convert primitive byte to Byte.
*/
public static final Byte toWrapper(byte obj) {
return new Byte(obj);
}
/**
* Convert Character object to primitive char.
*/
public static final char toPrimitive(Character obj) {
return obj.charValue();
}
/**
* Convert primitive char to Character.
*/
public static final Character toWrapper(char obj) {
return new Character(obj);
}
/**
* Convert Double object to primitive double.
*/
public static final double toPrimitive(Double obj) {
return obj.doubleValue();
}
/**
* Convert primitive double to Double.
*/
public static final Double toWrapper(double obj) {
return new Double(obj);
}
/**
* Convert Float object to primitive float.
*/
public static final float toPrimitive(Float obj) {
return obj.floatValue();
}
/**
* Convert primitive float to Float.
*/
public static final Float toWrapper(float obj) {
return new Float(obj);
}
/**
* Convert Integer object to primitive int.
*/
public static final int toPrimitive(Integer obj) {
return obj.intValue();
}
/**
* Convert primitive int to Integer.
*/
public static final Integer toWrapper(int obj) {
return new Integer(obj);
}
/**
* Convert Long object to primitive long.
*/
public static final long toPrimitive(Long obj) {
return obj.longValue();
}
/**
* Convert primitive long to Long.
*/
public static final Long toWrapper(long obj) {
return new Long(obj);
}
/**
* Convert Short object to primitive short.
*/
public static final short toPrimitive(Short obj) {
return obj.shortValue();
}
/**
* Convert primitive short to Short.
*/
public static final Short toWrapper(short obj) {
return new Short(obj);
}
/** The infomation about a primitive. */
private static class PrimInfo {
private final Class cls;
private final Object defVal;
private final char code;
private PrimInfo(Class cls, Object defVal, char code) {
this.cls = cls;
this.defVal = defVal;
this.code = code;
}
}
private static final Map _prims = new HashMap(23);
static {
_prims.put("int",
new PrimInfo(int.class, new Integer(0), 'I'));
_prims.put("boolean",
new PrimInfo(boolean.class, Boolean.FALSE, 'Z'));
_prims.put("short",
new PrimInfo(short.class, new Short((short)0), 'S'));
_prims.put("byte",
new PrimInfo(byte.class, new Byte((byte)0), 'B'));
_prims.put("char",
new PrimInfo(char.class, new Character((char)0), 'C'));
_prims.put("long",
new PrimInfo(long.class, new Long(0), 'L'));
_prims.put("double",
new PrimInfo(double.class, new Double(0), 'D'));
_prims.put("float",
new PrimInfo(float.class, new Float(0), 'F'));
_prims.put("void",
new PrimInfo(void.class, null, 'V'));
//we can use the same map because key is in diff class
_prims.put(Integer.class, int.class);
_prims.put(Boolean.class, boolean.class);
_prims.put(Short.class, short.class);
_prims.put(Byte.class, byte.class);
_prims.put(Character.class, char.class);
_prims.put(Long.class, long.class);
_prims.put(Double.class, double.class);
_prims.put(Float.class, float.class);
_prims.put(Void.class, void.class);
};
/** Returns the notation of a primitive class,
* or ((char)0) if it is not a primitive class.
* Example, I for int, Z for boolean...
*/
public static final char getNotation(String className) {
final PrimInfo pi = (PrimInfo)_prims.get(className);
return pi != null ? pi.code: (char)0;
}
/** Returns the default value of a primitive class,
* or null if it is not a primitive class.
* Example, getDefaultValue(int.class) returns Integer(0).
*/
public static final Object getDefaultValue(Class cls) {
final PrimInfo pi = (PrimInfo)_prims.get(cls.getName());
return pi != null ? pi.defVal: null;
}
/** Converts a primitive from name to the class,
* or null if it is not a primitive class.
* <p>Example, toClass("int") returns int.class.
*/
public static final Class toClass(String clsName) {
final PrimInfo pi = (PrimInfo)_prims.get(clsName);
return pi != null ? pi.cls: null;
}
/** Returns the primitive class of the giving wrapper class,
* or null if it is not a wrapper class.
* <p>Example, toPrimitive(Integer.class) returns int.class.
*/
public static final Class toPrimitive(Class wrapper) {
return (Class)_prims.get(wrapper);
}
/** Returns the wrapper class of a primitive class,
* or null if it is not a primitive class.
* <p>Example, toWrapper(int.class) return Integer.class.
*/
public static final Class toWrapper(Class primitive) {
if (!primitive.isPrimitive())
return null;
if (primitive.equals(void.class))
return Void.class;
return getDefaultValue(primitive).getClass();
}
/** Tests whether a class name is a primitive class, e.g., int and void.
*/
public static final boolean isPrimitive(String clsName) {
return _prims.containsKey(clsName);
}
}
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