java画图板的24位bmp保存

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

 

import javax.swing.JFileChooser;

import javax.swing.JOptionPane;

 

/**

 * 菜单处理监听器

 * 

 * @author kowloon

 * 

 */

public class MenuListener implements ActionListener {

 

private MyPanel panel;

 

public MenuListener(MyPanel panel) {

this.panel = panel;

}

 

// bmp文件头

public void savebmpTop(OutputStream ops) throws Exception {

ops.write('B');

ops.write('M');

int height = DrawListener.array.length;

int width = DrawListener.array[0].length;

int size = 14 + 40 + height * width * 3 + (4 - width * 3 % 4) * height;

// 位图文件的大小

size = 14 + 40 + height * width * 3 + (4 - width * 3 % 4) * 255;

writeInt(ops, size);

// 保留字节，必须为零

writeShort(ops, (short) 0);

writeShort(ops, (short) 0);

// 位图偏移量

writeInt(ops, 54);

}

 

// 位图信息头

public void savebmpInfo(OutputStream ops) throws Exception {

int height = DrawListener.array.length;

int width = DrawListener.array[0].length;

// 位图信息头长度

writeInt(ops, 40);

// 位图宽

writeInt(ops, width);

// 位图高

writeInt(ops, height);

// 位图位面数总是为1

writeShort(ops, (short) 1);

// 位图24位像素

writeShort(ops, (short) 24);

// 位图是否被压缩，0为不压缩

writeInt(ops, 0);

// 字节数代表位图大小

writeInt(ops, height * width * 3 + (4 - width * 3 % 4) * height);

// 水平分辨率

writeInt(ops, 0);

// 垂直分辨率

writeInt(ops, 0);

// 颜色索引，0为所有调色板

writeInt(ops, 0);

// 对图象显示有重要影响的颜色索引的数目。如果是0，表示都重要

writeInt(ops, 0);

}

 

// 图像数据阵列

public void savebmpDate(OutputStream ops) throws Exception {

int height = DrawListener.array.length;

int width = DrawListener.array[0].length;

int m = 0;

// 进行补0，必须是4位，少于4位要补0

if (width * 3 % 4 > 0) {

m = 4 - width * 3 % 4;

}

for (int i = height - 1; i >= 0; i--) {

for (int j = 0; j < width; j++) {

int t = DrawListener.array[i][j];

writeColor(ops, t);

}

for (int k = 0; k < m; k++) {

ops.write(0);

}

}

}

 

public void writeInt(OutputStream ops, int t) throws Exception {

int a = (t >> 24) & 0xff;

int b = (t >> 16) & 0xff;

int c = (t >> 8) & 0xff;

int d = t & 0xff;

ops.write(d);

ops.write(c);

ops.write(b);

ops.write(a);

}

 

public void writeColor(OutputStream ops, int t) throws Exception {

int b = (t >> 16) & 0xff;

int c = (t >> 8) & 0xff;

int d = t & 0xff;

ops.write(d);

ops.write(c);

ops.write(b);

}

 

public void writeShort(OutputStream ops, short t) throws Exception {

int c = (t >> 8) & 0xff;

int d = t & 0xff;

ops.write(d);

ops.write(c);

}

 

// 由于读取的是字节，把读取到的4个byte转化成1个int

public int changeInt(InputStream ips) throws IOException {

int t1 = ips.read() & 0xff;

int t2 = ips.read() & 0xff;

int t3 = ips.read() & 0xff;

int t4 = ips.read() & 0xff;

int num = (t4 << 24) + (t3 << 16) + (t2 << 8) + t1;

System.out.println(num);

return num;

}

 

// 24位的图片是1个像素3个字节。

public int readColor(InputStream ips) throws IOException {

int b = ips.read() & 0xff;

int g = ips.read() & 0xff;

int r = ips.read() & 0xff;

int c = (r << 16) + (g << 8) + b;

return c;

}

 

public void actionPerformed(ActionEvent e) {

// 获得被点击的组件的动作命令

String command = e.getActionCommand();

JFileChooser chooser = new JFileChooser();

if (command.equals("保存")) {

int t = chooser.showSaveDialog(null);

if (t == JFileChooser.APPROVE_OPTION) {

String path = chooser.getSelectedFile().getAbsolutePath();

try {

FileOutputStream fos = new FileOutputStream(path);

DataOutputStream dos = new DataOutputStream(fos);

 

savebmpTop(dos);

savebmpInfo(dos);

savebmpDate(dos);

fos.flush();

fos.close();

 

} catch (Exception ef) {

JOptionPane.showMessageDialog(null, "文件保存失败！！");

ef.printStackTrace();

}

}

} else if (command.equals("打开")) {

 

int t = chooser.showOpenDialog(null);

if (t == JFileChooser.APPROVE_OPTION) {

String path = chooser.getSelectedFile().getAbsolutePath();

try {

FileInputStream fis = new FileInputStream(path);

DataInputStream dis = new DataInputStream(fis);

 

dis.skip(18);

int width = changeInt(dis);// 跳过不需要的，读取宽度和高度

int height = changeInt(dis);

dis.skip(28);

// 跳过，直接读取位图数据。

DrawListener.array = new int[height][width];

int w = 0;

if (width * 3 % 4 > 0) {

t = 4 - width * 3 % 4;

}

for (int i = height - 1; i >= 0; i--) {

for (int j = 0; j < width; j++) {

// 调用自定义方法，得到图片的像素点并保存到int数组中

int c = readColor(dis);

DrawListener.array[i][j] = c;

}

dis.skip(w);

}

fis.close();

// 刷新界面

panel.repaint();

} catch (Exception ef) {

JOptionPane.showMessageDialog(null, "文件打开失败！！");

ef.printStackTrace();

}

}

}

 

}

 

}