《[Java]读取文件方法大全 》.docxVIP

 HYPERLINK /lovebread/archive/2009/11/23/1609122.html [Java]读取文件方法大全 1、按字节读取文件内容2、按字符读取文件内容3、按行读取文件内容 4、随机读取文件内容 public?class?ReadFromFile?{????/**?????*?以字节为单位读取文件，常用于读二进制文件，如图片、声音、影像等文件。?????*/????public?static?void?readFileByBytes(String?fileName)?{????????File?file?=?new?File(fileName);????????InputStream?in?=?null;????????try?{????????????System.out.println(以字节为单位读取文件内容，一次读一个字节：);????????????//?一次读一个字节????????????in?=?new?FileInputStream(file);????????????int?tempbyte;????????????while?((tempbyte?=?in.read())?!=?-1)?{????????????????System.out.write(tempbyte);????????????}????????????in.close();????????}?catch?(IOException?e)?{????????????e.printStackTrace();????????????return;????????}????????try?{????????????System.out.println(以字节为单位读取文件内容，一次读多个字节：);????????????//?一次读多个字节????????????byte[]?tempbytes?=?new?byte[100];????????????int?byteread?=?0;????????????in?=?new?FileInputStream(fileName);????????????ReadFromFile.showAvailableBytes(in);????????????//?读入多个字节到字节数组中，byteread为一次读入的字节数????????????while?((byteread?=?in.read(tempbytes))?!=?-1)?{????????????????System.out.write(tempbytes,?0,?byteread);????????????}????????}?catch?(Exception?e1)?{????????????e1.printStackTrace();????????}?finally?{????????????if?(in?!=?null)?{????????????????try?{????????????????????in.close();????????????????}?catch?(IOException?e1)?{????????????????}????????????}????????}????}????/**?????*?以字符为单位读取文件，常用于读文本，数字等类型的文件?????*/????public?static?void?readFileByChars(String?fileName)?{????????File?file?=?new?File(fileName);????????Reader?reader?=?null;????????try?{????????????System.out.println(以字符为单位读取文件内容，一次读一个字节：);????????????//?一次读一个字符????????????reader?=?new?InputStreamReader(new?FileInputStream(file));????????????int?tempchar;????????????while?((tempchar?=?reader.read())?!=?-1)?{????????????????//?对于windows下，\r\n这两个字符在一起时，表示一个换行。????????????????//?但如果这两个字符分开显示时，会换两次行。????????????????//?因此，屏蔽掉\r，或者屏蔽\n。否则，将会多出很多空行。?????