java分别通过字节流、字符流、二进制读取文件，java字节,import java.

java分别通过字节流、字符流、二进制读取文件，java字节,import java.

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();    }}