public?static?void?printToString(String?fileName)?throws?IOException?{
????????int?num?=?0;
????????int?count?=?0;
????????byte[]?buf?=?new?byte[8*1024];
????????
????????FileInputStream?file;
????????try?{
????????????file?=?new?FileInputStream(fileName);
????????????while?((num?=?file.read(buf))?!=?-1)?{
????????????????for?(int?i=0;?i<num;?++i)?{
????????????????????if?(++count%5?==?0)
????????????????????????System.out.println();????
????????????????????String?st?=?new?String(buf);
????????????????????
????????????????????System.out.print(st?+?"??");
????????????????}
????????????}
????????}?catch?(FileNotFoundException?e)?{
????????????//?TODO?Auto-generated?catch?block
????????????System.out.println("文件不存在！");
????????}
????????
????}

String?file?=?"C:\\Users\\Administrator\\Desktop\\1.txt";//文件路徑
FileInputStream?in?=?new?FileInputStream(file);
byte[]?buf?=?new?byte[20];//當字符串太長，就會放不下，你可以按需求設定長度，課程中用循環打印就是因為一次拿不完，循環來拿的
in.read(buf,0,buf.length);
String?s?=?new?String(buf);//這個s就是“我愛你中華”
System.out.println(s);