java 字节流读取图片，字符流读取，二进制读取

二进制文件读取图片，其实就是用字节流读取图片。其实就是用Java中提供的对字节流操作的类去操控图片文件

 

import java.io.*;import javax.swing.*;public class Start{public static void main(String args[]) throws Exception{//源文件，必须存在，路径可选File sf = new File("H:/javapro/files/source.jpg");//目的文件，因为要向其中写入，指定文件可以不存在，由程序生成File df = new File("H:/javapro/files/dest.jpg");new ReadWriteGra(sf,df);new UseGra(df);}}class ReadWriteGra {FileInputStream in = null;FileOutputStream out = null;public ReadWriteGra(File sourceFile,File destFile) throws Exception{byte[] buf = new byte[1024];int len = 0;in = new FileInputStream(sourceFile);out = new FileOutputStream(destFile,true);while( (len = in.read(buf)) != -1 ){out.write(buf,0,len);}out.close();}}class UseGra extends JFrame{public UseGra(File picFile) throws Exception{this.setVisible(true);this.setResizable(false);this.setLayout(null);this.setBounds(600, 200, 400, 370);this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);JPanel p1 = (JPanel)this.getContentPane();p1.setOpaque(false);p1.setLayout(null);InputStream is = new FileInputStream(picFile);ByteArrayOutputStream baos = new ByteArrayOutputStream();int b = 0;while((b = is.read())!=-1){baos.write(b);}ImageIcon image = new ImageIcon(baos.toByteArray());JLabel background = new JLabel(image);this.getLayeredPane().add(background, new Integer(Integer.MIN_VALUE));background.setBounds(0, 0, image.getIconWidth(), image.getIconHeight());JButton bt = new JButton("Test_Button");p1.add(bt);bt.setBounds(10,10,150,25);validate();}}