文件分割器（IO and NIO 两个版本）

package day20_work1.tarena.com; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.nio.ByteBuffer; import java.nio.channels.FileChannel; import javax.swing.JButton; import javax.swing.JFileChooser; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; /** * 使用文件缓冲区的文件分割与合并 * */ public class FilePartitionNio implements ActionListener { private JTextField jt1; private JTextField jt2; public FilePartitionNio() { JFrame jf = new JFrame("我的文件分割器"); jf.setLayout(new FlowLayout()); JLabel jl1 = new JLabel("文件"); JLabel jl2 = new JLabel("大小"); jt1 = new JTextField(20); jt2 = new JTextField(15); JButton jb1 = new JButton("打开"); JButton jb2 = new JButton("分割"); JButton jb3 = new JButton("合并"); jb1.addActionListener(this); jb2.addActionListener(this); jb3.addActionListener(this); jf.add(jl1); jf.add(jt1); jf.add(jb1); jf.add(jl2); jf.add(jt2); jf.add(jb2); jf.add(jb3); jf.setSize(350, 100); jf.setResizable(false); jf.setVisible(true); jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } public void Partition(String path, int num) { // 拆分文件 int i = 0; try { File f = new File(path); FileInputStream fis = new FileInputStream(f); FileChannel fc1 = fis.getChannel();//读文件通道 ByteBuffer b = ByteBuffer.allocate(num*1024); while (true) { int temp = fc1.read(b); if(temp == -1) break; FileOutputStream fos = new FileOutputStream(path + i); FileChannel fc2 = fos.getChannel();//写文件通道 b.flip();//限制设置为当前位置，位置设置为0 fc2.write(b); b.clear();//不清空，限制设为容量，位置设为position i++; System.out.println(temp); fc2.close(); fos.close(); } fc1.close(); f.delete(); System.out.println("拆分文件完毕"); fis.close(); } catch (Exception ee) { ee.printStackTrace(); } } public void unite(String path){ // 合并文件 int i = 0; try{ FileOutputStream fos = new FileOutputStream(path,true); FileChannel fc2 = fos.getChannel();//写文件通道 while(true){ File f = new File(path+i); if(f.exists()){ FileInputStream fis = new FileInputStream(f); FileChannel fc1 = fis.getChannel();//读文件通道 ByteBuffer b = ByteBuffer.allocate(1024); while (true) { int te = fc1.read(b); if (te == -1) break; b.flip();//限制设置为当前位置，位置设置为0 fc2.write(b); b.clear();//不清空，限制设为容量，位置设为position } fc1.close(); fis.close(); }else{ System.out.println("合并文件完毕"); break; } f.delete(); i++; } fc2.close(); fos.close(); }catch(Exception ee){ ee.printStackTrace(); } } @Override public void actionPerformed(ActionEvent e) { String comm = e.getActionCommand(); if ("打开".equals(comm)) { try { JFileChooser fc = new JFileChooser(); fc.showOpenDialog(null); jt1.setText(fc.getSelectedFile().getPath()); } catch (Exception ee) { ee.printStackTrace(); } } else if ("分割".equals(comm)) { if(!jt1.getText().equals("") && !jt2.getText().equals("")){ Partition(jt1.getText(), Integer.parseInt(jt2.getText())); }else{ System.out.println("请输入文件路径"); } } else if ("合并".equals(comm)) { if(!jt1.getText().equals("")){ unite(jt1.getText()); }else{ System.out.println("缺少文件名"); } } } public static void main(String[] args) { new FilePartitionNio(); } }