jtputil.java

用java实现的画图程序

package com.sunking.tp.util;

import java.io.*;
import java.net.*;
import java.awt.*;
import java.util.*;
import javax.swing.*;

/**
 * <p>Title: </p>
 * <p>Description: 实用工具类</p>
 * <p>Copyright: Copyright (c) 2003</p>
 * <p>Company: </p>
 * @author <a href="mailto:[e-mail]">SunKing</a>
 * @version 1.0
 */

public class JTPUtil {
    /**
     *存储图片资源的哈希表
     */
    private static Hashtable hImages;
    /**
     *取图片
     * @param name 图片文件名
     * @return
     */
    public static ImageIcon getImage(String name) {
        if (hImages == null) {
            hImages = getImageResource();
        }
        if (hImages != null) {
            return (ImageIcon) hImages.get(name);
        }
        return null;
    }

    /**
     *从JTP.jar文件里的JTP文件中取得图片资源
     * @return
     */
    private static Hashtable getImageResource() {
        try {
            String url = "jar:";
            url += "file:" + new File("").getAbsolutePath() + "/";
            while (url.indexOf(File.separator) != -1) {
                int index = url.indexOf(File.separator);
                url = url.substring(0, index) + "/" +
                    url.substring(index + 1, url.length());
            }
            url += "JTP.jar!/JTP";
            Vector vResult = new Vector();
            ObjectInputStream in = new ObjectInputStream(new URL(url).
                openStream());
            Object obj = in.readObject();
            in.close();
            return (Hashtable) obj;
        }
        catch (ClassNotFoundException ex) {
            return null;
        }
        catch (IOException ex) {
            return null;
        }
    }

    /**
     *生成JTP图象资源文件
     * @param argv
     */
    public static void main(String argv[]) {
        Hashtable v = new Hashtable();
        File f = new File("images/");
        File fs[] = f.listFiles();
        for (int i = 0; i < fs.length; i++) {
            v.put(fs[i].getName(),
                  new javax.swing.ImageIcon(fs[i].getAbsolutePath()));
            System.err.println(fs[i].getName());
        }
        writeObjectToFile("JTP", v);
    }

    /**
     *写入文件
     * @param fileName
     * @param obj
     * @return
     */
    public static boolean writeObjectToFile(String fileName, Object obj) {
        try {
            if (! (obj instanceof Serializable))
                return false;
            ObjectOutputStream out = new ObjectOutputStream(new
                FileOutputStream(fileName));
            out.writeObject(obj);
            out.flush();
            out.close();
            return true;
        }
        catch (Exception ex) {
            ex.printStackTrace();
            return false;
        }
    }

    /**
     *取图柄拖拉后的大小.
     * @param index  图柄序号
     * @param oldRec 原大小
     * @param mx   拖动横坐标改变大小
     * @param my   拖动纵坐标改变大小
     * @return
     */
    public static Rectangle getNewBounds(int index, Rectangle oldRec, int mx,
                                         int my) {
        int x = oldRec.x, y = oldRec.y, w = oldRec.width, h = oldRec.height;
        switch (index+4) {  //请注意这里加了4以和Cursor中的变量相匹配
            case Cursor.SW_RESIZE_CURSOR:
                x += mx;
                w -= mx;
                h += my;
                break;
            case Cursor.SE_RESIZE_CURSOR:
                w += mx;
                h += my;
                break;
            case Cursor.NW_RESIZE_CURSOR:
                x += mx;
                y += my;
                w -= mx;
                h -= my;
                break;
            case Cursor.NE_RESIZE_CURSOR:
                y += my;
                w += mx;
                h -= my;
                break;
            case Cursor.N_RESIZE_CURSOR:
                y += my;
                h -= my;
                break;
            case Cursor.S_RESIZE_CURSOR:
                h += my;
                break;
            case Cursor.W_RESIZE_CURSOR:
                x += mx;
                w -= mx;
                break;
            case Cursor.E_RESIZE_CURSOR:
                w += mx;
                break;
            default:
                break;
        }
        if (w < 0) {
            x += w;
            w = -w;
        }
        if (h < 0) {
            y += h;
            h = -h;
        }
        return new Rectangle(x, y, w, h);
    }
}