Question

java中如何将一个文件中的内容copy到另一个文件中

str = in.readLine();
File f1 = new File(str);
str = in.readLine();
File f2 = new File(str);
if(f1.isFile() && f2.isFile()){
FileReader reader=new FileReader(f1);
FileWriter Writer=new FileWriter(reader.read());

Answer 1

方式一：
File file1 = new File("D:/1.txt");
File file2 = new File("D:/2.txt");
if(file1.isFile() && file2.isFile()){
FileInputStream fis = new FileInputStream(file1);
FileOutputStream fos = new FileOutputStream(file2);
byte [] buffer = new byte[1024];
int len = 0;
while((len = fis.read(buffer)) != -1){
fos.write(buffer,0,len);
}
}

方式二：
File file1 = new File("D:/1.txt");
File file2 = new File("D:/2.txt");
if(file1.isFile() && file2.isFile()){
FileReader reader = new FileReader(file1);
FileWriter writer = new FileWriter(file2);
int len = 0;
while((len=reader.read()) != -1){
writer.write(len);
}
writer.flush();
}