[Java]把02.txt中的内容写入到05.txt中

//把02.txt中的内容写入到05.txt中
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class Backup
{
    public static void main(String[] args) throws IOException
    {
        FileReader in = new FileReader("02.txt");
        FileWriter out = new FileWriter("05.txt");
        int ch = in.read(); //.read()每次读取一个字符的ASCII值，如果读到结尾，返回-1
        while (ch != -1)
        {
            out.write(ch);
            ch = in.read();
        }
        in.close();
        out.close();
    }
}