JLabel保存为图片

本来想在JPanel上画图，然后保存为图片，但是发现如果循环创建JPanel保存图片太快，图片容易重叠出错，解决办法就是在JLabel上画图，代码如下：

import javax.swing.*;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

/**
 * Created by IntelliJ IDEA.
 * User: Administrator
 * Date: 2009-6-18
 * Time: 16:16:45
 * To change this template use File | Settings | File Templates.
 */
public class TestJLabel2Image {
    public static void main(String ds[]) {
        final String[] columnNames = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};

        final int[] columnValues = {3, 7, 2, 1, 0, 9, 4, 6, 5, 7};
        final int colorType = 1;

        int image_width = 180;
        int image_height = 180;

        final int table_width = 150;
        final int word_width = 20;
        final int word_height = 15;

        final int line_width = 10;
        final int line_height = 5;

        final JFrame f = new JFrame();
        JPanel panel = new JPanel(new BorderLayout());
        JLabel label = new JLabel() {
            public void paintComponent(Graphics g) {
                int x = 0;
                int y = 0;
                for (int i = 0; i < columnNames.length; i++) {
                    String s = columnNames[i];
                    int count = columnValues[i];
                    y = y + word_height;
                    g.drawString(s, x, y);

                    if (count != 0) {
                        int lineLength = 0;
                        if (count > 25) {
                            lineLength = line_width * 25;
                        } else {
                            lineLength = line_width * count;
                        }
                        if (colorType == 1) {
                            g.setColor(Color.RED);
                        } else {
                            g.setColor(Color.BLUE);
                        }
                        g.fillRect(x + word_width, y - 5, lineLength, line_height);
                        g.setColor(Color.BLACK);
                        g.drawString(String.valueOf(count), x + word_width + lineLength + 5, y);

                    } else {
                        //g.drawString(String.valueOf(count), x + word_width, y);
                    }
                }
                g.dispose();

            }
        };
        panel.setPreferredSize(new Dimension(table_width, image_height));
        panel.add(label, BorderLayout.CENTER);
        f.getContentPane().add(panel);
        f.setSize(table_width, image_height);
        //f.setVisible(true);
        f.pack();

        BufferedImage image = createImage(panel);

        f.dispose();

        //对图片进行压缩处理，输出到指定目录
        reduceImg(image, "d:/test.png", image_width, image_height);
    }

    public static BufferedImage createImage(JPanel panel) {

        int totalWidth = panel.getPreferredSize().width;
        int totalHeight = panel.getPreferredSize().height;
        BufferedImage panelImage = new BufferedImage(totalWidth, totalHeight, BufferedImage.TYPE_INT_RGB);

        Graphics2D g2D = (Graphics2D) panelImage.createGraphics();

        g2D.setColor(Color.WHITE);
        g2D.fillRect(0, 0, totalWidth, totalHeight);
        g2D.translate(0, 0);

        panel.paint(g2D);

        g2D.dispose();
        return panelImage;
    }

public static void reduceImg(BufferedImage bufferedImage, String imgdist, int widthdist,
                                 int heightdist) {
        try {
            BufferedImage tag = new BufferedImage(widthdist,
                    heightdist, BufferedImage.TYPE_INT_RGB);
            /*
            * Image.SCALE_SMOOTH 的缩略算法  生成缩略图片的平滑度的
            * 优先级比速度高 生成的图片质量比较好 但速度慢
            */
            tag.getGraphics().drawImage(
                    bufferedImage.getScaledInstance(widthdist, heightdist,
                            Image.SCALE_SMOOTH), 0, 0, null);


            ImageIO.write(tag, "png", new File(imgdist));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

和我另一篇JTable to Image代码基本一致，希望对大家有帮助
http://www.iteye.com/topic/386716

评论

1 楼 swen00 2009-06-18  

图片压缩代码是借用JE上的