工具类:
  import java.awt.FlowLayout;
  import java.awt.Toolkit;
  import java.awt.event.ActionListener;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import javax.swing.JButton;
  import javax.swing.JFrame;
  import javax.swing.JPanel;
  public class FileSplitUtilClass {
  public static int data;//拆分的个数;
  public static String str;
  public static boolean split(File filePath,int number) {
  byte[] b=new byte[number];
  str=filePath.getAbsolutePath();
  int i=0;//创建文件
  try {
  FileInputStream file=new FileInputStream(filePath);
  try {
  while(file.read(b)!=-1){
  i++;
  FileOutputStream fileout=new FileOutputStream(str+i);
  fileout.write(b);
  }
  file.close();
  FileSplitUtilClass.data=i;
  filePath.delete();
  return true;
  }catch (IOException e) {
  // TODO Auto-generated catch block
  System.out.println("split error");
  e.printStackTrace();return false;
  }
  } catch (FileNotFoundException e) {
  // TODO Auto-generated catch block
  System.out.println("no find");
  e.printStackTrace();return false;
  }
  }
  ////////////////////////////////////////
  public static void fixFile(File filePath){
  byte[] b=new byte[1024];
  // String str=filePath.getAbsolutePath();
  int i=0;//创建文件
  try {
  FileOutputStream file=new FileOutputStream(filePath);
  try {
  System.out.println(FileSplitUtilClass.data);
  while(true&i<FileSplitUtilClass.data){
  i++;
  FileInputStream file1=new FileInputStream(FileSplitUtilClass.str+i);
  if(file1.read(b)!=-1){
  file.write(b);
  }else{
  break;
  }
  }
  }catch (IOException e) {
  // TODO Auto-generated catch block
  System.out.println("no file");
  e.printStackTrace();
  }
  } catch (FileNotFoundException e) {
  // TODO Auto-generated catch block
  System.out.println("failure");
  e.printStackTrace();
  }
  }
/////////////////////
  public static JFrame getJFrame(String JFrameName){
  JFrame jf=new JFrame(JFrameName);
  Toolkit tk=Toolkit.getDefaultToolkit();
  jf.setSize(500,330);
  jf.setLocation((tk.getScreenSize().width-jf.getWidth())/2,(tk.getScreenSize().height-jf.getHeight())/2);
  return jf;
  }
  //////////////////////////
  public static JPanel getJButton(String JButtonName1,String JButtonName2,Object obj){
  JPanel jp=new JPanel(new FlowLayout());
  JButton jb1=new JButton(JButtonName1);
  jb1.addActionListener((ActionListener) obj);
  JButton jb2=new JButton(JButtonName2);
  jb2.addActionListener((ActionListener)obj);
  jp.add(jb1);
  jp.add(jb2);
  return jp;
  }
  ///////////////////////////////////////
  }
  检测类:
  import java.awt.BorderLayout;
  import java.awt.FlowLayout;
  import java.awt.event.ActionEvent;
  import java.awt.event.ActionListener;
  import java.io.File;
  import javax.swing.JFileChooser;
  import javax.swing.JFrame;
  import javax.swing.JLabel;
  import javax.swing.JPanel;
  import javax.swing.JTextField;
  public class Split implements ActionListener {
  JFrame jf;JTextField jt;int number;
  public Split(){
  jf=FileSplitUtilClass.getJFrame("Filesplit");
  JPanel jp=FileSplitUtilClass.getJButton("拆分","组合", this);
  jt=new JTextField(10);
  JLabel jl=new JLabel("输入字节大小");
  JPanel jp1=new JPanel(new FlowLayout());
  jp1.add(jl);jp1.add(jt);
  jf.add(jp1,BorderLayout.CENTER);
  jf.add(jp,BorderLayout.SOUTH);
  jf.setVisible(true);
  javax.swing.JOptionPane.showMessageDialog(jf,"请输入字节");
  jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }
  public void actionPerformed(ActionEvent arg0) {
  // TODO Auto-generated method stub
  String str=arg0.getActionCommand();
  if("拆分".equals(str)){
  JFileChooser jfc=new JFileChooser();
  jfc.showOpenDialog(null);//注意在这里的null表示对话框弹出的位置;
  if(jfc.showOpenDialog(null)==JFileChooser.APPROVE_OPTION){
  File filePath=jfc.getSelectedFile();
  if(FileSplitUtilClass.split(filePath,Integer.parseInt(jt.getText()))){
  javax.swing.JOptionPane.showMessageDialog(jf,"ok");
  }else{
  javax.swing.JOptionPane.showMessageDialog(jf,"fail");
  }
  }else{
  javax.swing.JOptionPane.showMessageDialog(jf,"你已经取消了");
  }
  }
  if("组合".equals(str)){
  JFileChooser jfc=new JFileChooser();
  jfc.showOpenDialog(null);//注意在这里的null表示对话框弹出的位置;
  if(jfc.showOpenDialog(null)==JFileChooser.APPROVE_OPTION){
  File filePath=jfc.getSelectedFile();
  FileSplitUtilClass.fixFile(filePath);
  javax.swing.JOptionPane.showMessageDialog(jf,"fixed ok");
  }else{
  javax.swing.JOptionPane.showMessageDialog(jf,"你已经取消了");
  }
  }
  }
  public static void main(String[] args){
  Split s=new Split();
  }
  }