linkutil.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

// **********************************************************************
// 
// <copyright>
// 
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  [phone]
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// 
// </copyright>
// **********************************************************************
// 
// $Source:
// /cvs/distapps/openmap/src/openmap/com/bbn/openmap/layer/link/LinkUtil.java,v
// $
// $RCSfile: LinkUtil.java,v $
// $Revision: 1.2.2.1 $
// $Date: 2004/10/14 18:27:09 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.layer.link;

import java.io.DataInput;
import java.io.IOException;

public class LinkUtil {

    /**
     * readString reads an expected number of characters off a
     * DataInput and creates a String from it.
     * 
     * @param length the number of characters to be read..
     */
    protected static String readString(DataInput dis, int length)
            throws IOException, ArrayIndexOutOfBoundsException {
        String ret = null;
        char[] chars = new char[length];

        for (int i = 0; i < length; i++) {
            chars[i] = dis.readChar();
        }
        ret = new String(chars);
        return ret;
    }

    /** Provided as a readability convenience. */
    public static int setMask(int value, int mask) {
        return (value | mask);
    }

    /** Provided as a readability convenience. */
    public static int unsetMask(int value, int mask) {
        return (value & ~mask);
    }

    /** Provided as a readability convenience. */
    public static boolean isMask(int value, int mask) {
        if ((value & mask) == 0) {
            return false;
        }
        return true;
    }
}