Token.java

/*
 * PhoneGap is available under *either* the terms of the modified BSD license *or* the
 * MIT License (2008). See http://opensource.org/licenses/alphabetical for full text.
 * 
 * Copyright (c) 2011, IBM Corporation
 */

package com.phonegap.json4j.internal;

/**
 * Class representing a JSON token.
 */
public class Token {

    static final public Token TokenEOF    = new Token();
    static final public Token TokenBraceL = new Token();
    static final public Token TokenBraceR = new Token();
    static final public Token TokenBrackL = new Token();
    static final public Token TokenBrackR = new Token();
    static final public Token TokenColon  = new Token();
    static final public Token TokenComma  = new Token();
    static final public Token TokenTrue   = new Token();
    static final public Token TokenFalse  = new Token();
    static final public Token TokenNull   = new Token();

    private String  valueString;
    private Object  valueNumber;
    private boolean  isConstant;

    /**
     * Constructor
     */
    public Token() {
        super();
    }

    /**
     * Constructor
     * @param value The value of the token as a string
     */
    public Token(String value) {
        super();
        valueString = value;
    }
    
    /**
     * Constructor
     * @param value The value of the token as a number
     */
    public Token(Object value) {
        super();

        valueNumber = value;
    }

    /**
     * Method to obtain the string value of this token
     */
    public String getString() {
        return valueString;
    }

    /**
     * Method to obtain the number value of this token
     */
    public Object getNumber() {
        return valueNumber;
    }

    /**
     * Method to indicate if this token is string based or not.
     */
    public boolean isString() {
        return (null != valueString) && !isConstant;
    }

    /**
     * Method to indicate if this token is number based or not.
     */
    public boolean isNumber() {
        return null != valueNumber;
    }

    /**
     * Method to convert the token to a string representation.
     */
    public String toString() {
        if (this == TokenEOF)    return "Token: EOF";
        if (this == TokenBraceL) return "Token: {";
        if (this == TokenBraceR) return "Token: }";
        if (this == TokenBrackL) return "Token: [";
        if (this == TokenBrackR) return "Token: ]";
        if (this == TokenColon)  return "Token: :";
        if (this == TokenComma)  return "Token: ,";
        if (this == TokenTrue)   return "Token: true";
        if (this == TokenFalse)  return "Token: false";
        if (this == TokenNull)   return "Token: null";

        if (this.isNumber()) return "Token: Number - " + getNumber();
        if (this.isString()) return "Token: String - '" + getString() + "'";

        return "Token: unknown.";
    }
}