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package com.ksyzt.gwt.server.common;

import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;


/**
 * thumbnail
 *
 * @author 54powerman
 * @version 1.0
 */
public class Thumbnail {

    /**
     * The src file.
     */
    private String srcFile;

    /**
     * The dest file.
     */
    private String destFile;

    /**
     * The width.
     */
    private int width;

    /**
     * The height.
     */
    private int height;

    /**
     * The img.
     */
    private Image img;

    /**
     * The main method.
     *
     * @param args the arguments
     * @throws Exception the exception
     */
    public static void main(String[] args) throws Exception {

    }

    /**
     * 构造函数.
     *
     * @param fileName String
     * @param dest     the dest
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public Thumbnail(String fileName, String dest) throws IOException {
        File _file = new File(fileName); // 读入文件
        this.srcFile = _file.getName();
        this.destFile = dest;
        img = javax.imageio.ImageIO.read(_file); // 构造Image对象
        width = img.getWidth(null); // 得到源图宽
        height = img.getHeight(null); // 得到源图长
    }

    /**
     * 强制压缩/放大图片到固定的大小.
     *
     * @param w int 新宽度
     * @param h int 新高度
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public void resize(int w, int h) throws IOException {
        BufferedImage _image = new BufferedImage(w, h,
                BufferedImage.TYPE_INT_RGB);

        _image.getGraphics().drawImage(
                img.getScaledInstance(w, h, Image.SCALE_SMOOTH), 0, 0, w, h,
                null); // 绘制缩小后的图
        // FileOutputStream out = new FileOutputStream(destFile); // 输出到文件流
        // JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        // encoder.encode(_image); // 近JPEG编码
        saveImage(_image, destFile);
        // out.close();
    }

    /**
     * Save image.
     *
     * @param dstImage the dst image
     * @param dstName  the dst name
     * @throws IOException Signals that an I/O exception has occurred.
     */
    static void saveImage(BufferedImage dstImage, String dstName)
            throws IOException {
        String formatName = dstName.substring(dstName.lastIndexOf(".") + 1);
        // FileOutputStream out = new FileOutputStream(dstName);
        // JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        // encoder.encode(dstImage);
        ImageIO.write(dstImage, /* "GIF" */formatName /* format desired */,
                new File(dstName) /* target */);
    }

    /**
     * 按照固定的比例缩放图片.
     *
     * @param t double 比例
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public void resize(double t) throws IOException {
        int w = (int) (width * t);
        int h = (int) (height * t);
        resize(w, h);
    }

    /**
     * 以宽度为基准，等比例放缩图片.
     *
     * @param w int 新宽度
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public void resizeByWidth(int w) throws IOException {
        int h = (int) (height * w / width);
        resize(w, h);
    }

    /**
     * 以高度为基准，等比例缩放图片.
     *
     * @param h int 新高度
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public void resizeByHeight(int h) throws IOException {
        int w = (int) (width * h / height);
        resize(w, h);
    }

    /**
     * 按照最大高度限制，生成最大的等比例缩略图.
     *
     * @param w int 最大宽度
     * @param h int 最大高度
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public void resizeFix(int w, int h) throws IOException {
        if (width / height > w / h) {
            resizeByWidth(w);
        } else {
            resizeByHeight(h);
        }
    }

    /**
     * 设置目标文件名 setDestFile.
     *
     * @param fileName String 文件名字符串
     * @throws Exception the exception
     */
    public void setDestFile(String fileName) throws Exception {
        if (!fileName.endsWith(".jpg")) {
            throw new Exception("Dest File Must end with \".jpg\".");
        }
        destFile = fileName;
    }

    /**
     * 获取目标文件名 getDestFile.
     *
     * @return the dest file
     */
    public String getDestFile() {
        return destFile;
    }

    /**
     * 获取图片原始宽度 getSrcWidth.
     *
     * @return the src width
     */
    public int getSrcWidth() {
        return width;
    }

    /**
     * 获取图片原始高度 getSrcHeight.
     *
     * @return the src height
     */
    public int getSrcHeight() {
        return height;
    }
}