9.7 DataInputStreams
DataInputStreams與FileInputStreams差不多。Data流可以直接讀任意一種變 量類型, 如浮點數(shù),整數(shù)和字符等。一般來說,對二進制文件使用DataInputStream流。
9.7.1 打開和關(guān)閉DataInputStreams
打開和關(guān)閉DataInputStreams對象時, 其方法與FileInputStreams相同:
DataInputStreams myDataStream;
FileInputStreams myFileStream;
//get a file handle
myFileStream = new FileInputStream("/usr/db/stock.dbf");
//open,or "chain" a data input file
myDataStream = new DataOutputStream(myFileStream);
//Now we can use both input streams to access our file
//j(If we want to...)
myFileStream.read(b);
I = myDataStrea.readInt();
//close the data friel explicityly
//Always close the "topmost" file stream
myDataStream.close();
myFileStream.close();
9.7.2 讀DataInputStreams
當你從DataInputStreams流里訪問文件時,你可以使用與FileInputStream流相同的成員函數(shù) read()。 但你也可以使用其他訪問方法來讀取不同種類的數(shù)據(jù):
byte readByte(),int readUnsignedByte(),short readShort(),int readUnsighedShort(),char readChar(),int readInt(),long readLong(),float readFloat(),double readDouble(),String readLine() 以上每一個成員函數(shù)都讀取相應(yīng)的數(shù)據(jù)對象。象String readLine()成員函數(shù),你可使用\n,\r,\r\n,或EOF作為字符 結(jié)束 符。
讀一個長整型,例如:
long serialNo;
serialNo = myDataStream.readLong();