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The trick in iterating through the Scanner token is to use those methods which starts with has like hasNext, hasNextInt, etc.

If we want to have a locale specific we just have to declare it using one of the Scanner method eLocale(Locale.ENGLISH) We just have to declare it using the Scanner constructor like for example: Scanner scan = new Scanner(new File("C:/test.txt")) Reading a file is very easy using the Scanner class. package įileInputStream fis = new FileInputStream(input) We have used the FileInputStream for below example as it is a subclass of InputStream, there would not be an issue in using it. However we can use the subclasses of InputStream as shown below. The InputStream class is one of the top level classes in the java.io package and using it would be a problem. The method input on this constructor is InputStream.

A Scanner breaks its input into tokens using a delimiter pattern, which by default matches whitespace. A simple text scanner which can parse primitive types and strings using regular expressions.

("Error Reading File") Ĭonstructs a new Scanner that produces values scanned from the specified input stream. The simplest one is to make use of the class Scanner, which is part of the java.util library and has been newly introduced in Java 5.0. package įileReader reader = new FileReader(new File("D:temptest.txt")) Which means, we can use any of these classes in instantiating the Scanner object. Readable is an interface which has been implemented by BufferedReader, CharArrayReader, CharBuffer, FileReader, FilterReader, InputStreamReader, LineNumberReader, PipedReader, PushbackReader, Reader, StringReader. Source – A character source implementing the Readable interfaceĭon’t get confused on the Object type Readable as constructor parameter. Constructs a new Scanner that produces values scanned from the specified source.