public class CopyFile {?? ?public static void copyfile(File file1,File file2) throws IOException {?? ??? ?FileInputStream in=new FileInputStream(file1);?? ??? ?FileOutputStream out=new FileOutputStream(file2);?? ??? ?int b;?? ??? ?while((b=in.read())!=-1){?? ??? ??? ?byte[] buf=new byte[5*1024];?? ??? ??? ?in.read(buf,0,buf.length);?? ??? ??? ?out.write(buf,0,b);?? ??? ??? ??? ??? ?}?? ??? ?in.close();?? ??? ?out.close();?? ?}?? ?public static void main(String[] args) throws IOException {?? ??? ?File filea=new File("demo/a.txt");?? ??? ?if(!filea.exists())?? ??? ??? ?filea.createNewFile();?? ??? ?File fileb=new File("demo/b.txt");?? ??? ?if(!fileb.exists())?? ??? ??? ?fileb.createNewFile();?? ??? ?copyfile(filea,fileb);?? ?}}工程編碼,a文件,b文件都是 utf-8 在a寫入的文字,執行程序后b文件里面顯示的第一個中文是亂碼如果寫入的是英文就不會有問題