读取文件内容

public class UseBuffer {
public static  void main(String[] args) throws IOException{
final int  SIZE = 1024;
File fileIn = new File ("./src/txt/","1.txt");
FileInputStream in =
new FileInputStream(fileIn);
File fileOut = new File("./src/txt/","2.txt");
FileOutputStream out =
new FileOutputStream(fileOut);
//创建byte数组
byte[] buff = new byte[SIZE];

int num = in.read(buff);
while(num!=-1){
out.write(buff,0,num);
num = in.read();
}
in.close();
out.close();
}
}

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class FileTest2 {
public static void main(String[] args) throws IOException {
//将变量存入 System
System.setProperty("use.dir", "./src/picture");
//得到Properties
String usedir = System.getProperty("use.dir");
System.out.println("用户路径为  ："+usedir);

File file = new File(usedir,"IMAG0056.jpg");
System.out.println("check whether the file is exsist : "+file.isFile());
System.out.println("check the length of the file :"+file.length());

File fileOut = new File(usedir,"IMAG0057.jpg");
//输入流
FileInputStream in = new FileInputStream(file);
//输出流
FileOutputStream out =  new FileOutputStream(fileOut);

//建立缓冲区
int SIZE  = 1024;
byte[] buff = new byte[SIZE];

//从输入流中读取内容
int num = in.read(buff);
//写入到输出流之中
while(num!=-1){
out.write(buff);
num = in.read(buff);
}
in.close();
out.close();
}
}

public class TestWrite {
//源文件
private  File inFile = new File("./src/com/cici/test/1.txt");
//目的文件
private  File outFile = new File("./src/com/cici/test/2.txt");
// 输入流
private FileInputStream in ;
// 输出流
private  FileOutputStream out ;
//buff字节字符串
byte []  buff = new byte[190];

public TestWrite() throws FileNotFoundException {
in = new FileInputStream(inFile);
out = new FileOutputStream(outFile);
}

public static void main(String[] args) throws Exception {
TestWrite tw = new TestWrite();
tw.methodReadWrite(0,0);
}

public void methodReadWrite(int begin,int length) throws Exception{

int num = in.read(buff);
System.out.println("num ---- "+num);
if(begin==0)
out.write(buff, 0, num);
if(num!=-1){
begin = num;
length = 2*num;
methodReadWrite(num, num+num);
}else{
return;
}
}
}