int b = in.read(); //读取一个字节无符号填充到int低八位。-1是EOF。
 in.read(byte[] buf); //读取数据填充到字节数组buf中。返回的是读到的字节个数。
 in.read(byte[] buf,int start, int size)//读取数据到字节数组buf从buf的start位置开始存放size长度分数据

out.write(int b)//写出一个byte到流，b的低8位
out.write(byte[] buf)//将buf字节数组都写到流
out.write(byte[] buf, int start,int size) //字节数组buf从start位置开始写size长度的字节到流

/**
  * 读取指定文件内容,按照16进制输出到控制台
  * 并且每输出10个byte换行
  * @throws FileNotFoundException 
  */
 public static void printHex(String fileName) throws IOException{
  //把文件作为字节流进行读操作
  FileInputStream in=new FileInputStream(fileName);
  int b;
  int count=0;//计数读到的个数
  while((b=in.read())!=-1){
   if(b<=0xf){
    //单位数前面补0
    System.out.println("0");
   }
   System.out.print(Integer.toHexString(b& 0xff)+" ");
   if(++count==0){
    System.out.println();
   }
  }
  in.close();//一定要关闭流
 }

public static void printHexByBytes(String fileName) throws IOException{
  FileInputStream in=new FileInputStream(fileName);
  byte[] buf=new byte[20*1024];//开辟一个20k大小的字节数组
  /*
   * 从in中批量读取字节，放入到buf这个字节数组中
   * 从第0个位置开始放，最多放buf.length个
   * 返回的是读到的字节个数
   */
  //一次性读完的情况
  int count=in.read(buf, 0, buf.length);
  int j=1;
  for(int i=0;i<count;i++){
   if((buf[i]&0xff)<=0xf){
    //单位数前面补0
    System.out.print("0");
   }
   System.out.print(Integer.toHexString(buf[i]&0xff)+ " ");
   if(j++==0){
    System.out.println();
   }
  }
    in.close();
 }
}

public static void printHexByBytes(String fileName) throws IOException{
  FileInputStream in=new FileInputStream(fileName);
  byte[] buf=new byte[20*1024];//开辟一个20k大小的字节数组
  /*
   * 从in中批量读取字节，放入到buf这个字节数组中
   * 从第0个位置开始放，最多放buf.length个
   * 返回的是读到的字节个数
   */
  int j=1;
  //一个字节数组读不完的情况，用while循环重复利用此数组直到读到文件末=-1
  int b=0;
  while((b=in.read(buf, 0, buf.length))!=-1){
   for(int i=0;i<b;i++){
    if((buf[i]&0xff)<=0xf){
     //单位数前面补0
     System.out.print("0");
    }
    System.out.print(Integer.toHexString(buf[i]&0xff)+ " ");
    if(j++==0){
     System.out.println();
    }
   }
  }
  in.close();
 }
}

//如果该文件不存在，则直接创建，如果存在，删除后创建
  FileOutputStream out = new FileOutputStream("demo/new1.txt");//以路径名称构造

//如果该文件不存在，则直接创建，如果存在，在文件后追加内容
   FileOutputStream out = new FileOutputStream("demo/new1.txt",true);
更多内容可以查询API。

out.wirte(‘A');//写出了‘A'的低八位
int a=10;//wirte只能写八位，那么写一个int需要写4次，每次八位
out.write(a>>>24);
out.write(a>>>16);
out.write(a>>>8);
out.wirte(a);

public static void copyFile(File srcFile,File destFile)throws IOException{
  if(!srcFile.exists()){
   throw new IllegalArgumentException("文件："+srcFile+"不存在");
  }
  if(!srcFile.isFile()){
   throw new IllegalArgumentException(srcFile+"不是一个文件");
  }
  FileInputStream in =new FileInputStream(srcFile);
  FileOutputStream out =new FileOutputStream(destFile);
  
  byte[] buf=new byte[8*1024];
  int b;
  while((b=in.read(buf, 0, buf.length))!=-1){
   out.write(buf, 0, b);
   out.flush();//最好加上
  }
  in.close();
  out.close();
 }

try {
  IOUtil.copyFile(new File("C:\\Users\\acer\\workspace\\encode\\new4\\test1"), new File("C:\\Users\\acer\\workspace\\encode\\new4\\test2"));
 } catch (IOException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }
 }

String file="demo/data.txt";
   DataOutputStream dos= new DataOutputStream(new FileOutputStream(file));

dos.writeInt(10);
  dos.writeInt(-10);
  dos.writeLong(10l);
  dos.writeDouble(10.0);
  //采用utf-8编码写出
  dos.writeUTF("中国");
  //采用utf-16be（java编码格式）写出
  dos.writeChars("中国");

String file="demo/data.txt";
  IOUtil.printHex(file);
  DataInputStream dis=new DataInputStream(new FileInputStream(file));
  int i=dis.readInt();
  System.out.println(i);
  i=dis.readInt();
  System.out.println(i);
  long l=dis.readLong();
  System.out.println(l);
  double d=dis.readDouble();
  System.out.println(d);
  String s= dis.readUTF();
  System.out.println(s);
  dis.close();

try {
  long start=System.currentTimeMillis();
  //IOUtil.copyFile(new File("C:\\Users\\acer\\Desktop\\学习路径.docx"), new File("C:\\Users\\acer\\Desktop\\复制文本.docx"));
  long end=System.currentTimeMillis();
  System.out.println(end-start);
 } catch (IOException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }

/*
  * 单字节进行文件的拷贝，利用带缓冲的字节流
  */
 public static void copyFileByBuffer(File srcFile,File destFile)throws IOException{
  if(!srcFile.exists()){
   throw new IllegalArgumentException("文件："+srcFile+"不存在");
  }
  if(!srcFile.isFile()){
   throw new IllegalArgumentException(srcFile+"不是一个文件");
  }
  BufferedInputStream bis=new BufferedInputStream(new FileInputStream(srcFile));
  BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(destFile));
  int c;
  while((c=bis.read())!=-1){
   bos.write(c);
   bos.flush();//刷新缓冲区
  }
  bis.close();
  bos.close();
 }

/*
  * 单字节不带缓冲进行文件拷贝
  */
 public static void copyFileByByte(File srcFile,File destFile)throws IOException{
  if(!srcFile.exists()){
   throw new IllegalArgumentException("文件："+srcFile+"不存在");
  }
  if(!srcFile.isFile()){
   throw new IllegalArgumentException(srcFile+"不是一个文件");
  }
  FileInputStream in=new FileInputStream(srcFile);
  FileOutputStream out=new FileOutputStream(destFile);
  int c;
  while((c=in.read())!=-1){
   out.write(c);
   out.flush();//不带缓冲，可加可不加
  }
  in.close();
  out.close();
 }

/*
  * 字节批量拷贝文件，不带缓冲
  */
 public static void copyFile(File srcFile,File destFile)throws IOException{
  if(!srcFile.exists()){
   throw new IllegalArgumentException("文件："+srcFile+"不存在");
  }
  if(!srcFile.isFile()){
   throw new IllegalArgumentException(srcFile+"不是一个文件");
  }
  FileInputStream in =new FileInputStream(srcFile);
  FileOutputStream out =new FileOutputStream(destFile);
  
  byte[] buf=new byte[8*1024];
  int b;
  while((b=in.read(buf, 0, buf.length))!=-1){
   out.write(buf, 0, b);
   out.flush();//最好加上
  }
  in.close();
  out.close();
 }

/*
  * 多字节进行文件的拷贝，利用带缓冲的字节流
  */
 public static void copyFileByBuffers(File srcFile,File destFile)throws IOException{
  if(!srcFile.exists()){
   throw new IllegalArgumentException("文件："+srcFile+"不存在");
  }
  if(!srcFile.isFile()){
   throw new IllegalArgumentException(srcFile+"不是一个文件");
  }
  BufferedInputStream bis=new BufferedInputStream(new FileInputStream(srcFile));
  BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(destFile));
  byte[] buf=new byte[20*1024];
  int c;
  while((c=bis.read(buf, 0, buf.length))!=-1){
   bos.write(buf, 0, c);
   bos.flush();//刷新缓冲区
  }
  bis.close();
  bos.close();
 }

String file1="C:\\Users\\acer\\workspace\\encode\\new4\\test1";
  String file2="C:\\Users\\acer\\workspace\\encode\\new4\\test2";
  InputStreamReader isr=new InputStreamReader(new FileInputStream(file1));
  OutputStreamWriter osw=new OutputStreamWriter(new FileOutputStream(file2));
//  int c;
//  while((c=isr.read())!=-1){
//   System.out.print((char)c);
//  }
  char[] buffer=new char[8*1024];
  int c;
  //批量读取，放入buffer这个字符数组，从第0个位置到数组长度
  //返回的是读到的字符个数
  while((c=isr.read(buffer,0,buffer.length))!=-1){
   String s=new String(buffer,0,c);//将char类型数组转化为String字符串
   System.out.println(s);
   osw.write(buffer,0,c);
   osw.flush();
   //osw.write(s);
   //osw.flush();
  }
  isr.close();
  osw.close();

 FileReader fr = new FileReader("C:\\Users\\acer\\workspace\\encode\\new4\\test1"); //输入流
 FileWriter fw = new FileWriter(C:\\Users\\acer\\workspace\\encode\\new4\\test2");//输出流

char[] buffer=new char[8*1024];
  int c;
  while((c=fr.read(buffer, 0, buffer.length))!=-1){
   fw.write(buffer, 0, c);
   fw.flush();
  }
  fr.close();
  fw.close();

BufferedReader br ＝new BufferedReader(new InputStreamReader(new FileInputStream(目录的地址)))
BufferedWriter br ＝new BufferedWriter(new InputStreamWriter(new FileOutputStream(目录的地址)))
PrintWriter pw=new PrintWriter(目录/Writer/OutputStream/File);

//对文件进行读写操作
  String file1="C:\\Users\\acer\\workspace\\encode\\new4\\test1";
  String file2="C:\\Users\\acer\\workspace\\encode\\new4\\test2";
  BufferedReader br = new BufferedReader(new InputStreamReader(
    new FileInputStream(file1)));
  BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(
    new FileOutputStream(file2)));
String line;
  while((line=br.readLine())!=null){
   System.out.println(line);//一次读一行，并不能识别换行
   bw.write(line);
   //单独写出换行操作
   bw.newLine();
   bw.flush();
}
    br.close();
  bw.close();
}

String file1="C:\\Users\\acer\\workspace\\encode\\new4\\test1";
  String file2="C:\\Users\\acer\\workspace\\encode\\new4\\test2";
  BufferedReader br = new BufferedReader(new InputStreamReader(
    new FileInputStream(file1)));
PrintWriter pw=new PrintWriter(file2);
//PrintWriter pw=new PrintWriter(outputStream, autoFlush);//可以指定是否自动flush
String line;
  while((line=br.readLine())!=null){
   System.out.println(line);//一次读一行，并不能识别换行
   pw.println(line);//自动换行
   pw.flush();//指定自动flush后不需要写
  }
  br.close();
  pw.close();
}