Difference between buffered reader and file reader

问题:

This question already has an answer here:

• Scanner vs. BufferedReader 12 answers

Can anyone explain me the difference between the class BufferedReader, FileReader and Scanner? and which one to use when I want to read a text file?

回答1:

Well:

• FileReader is just a Reader which reads a file, using the platform-default encoding (urgh)
• BufferedReader is a wrapper around another Reader, adding buffering and the ability to read a line at a time
• Scanner reads from a variety of different sources, but is typically used for interactive input. Personally I find the API of Scanner to be pretty painful and obscure.

To read a text file, I would suggest using a FileInputStream wrapped in an InputStreamReader (so you can specify the encoding) and then wrapped in a BufferedReader for buffering and the ability to read a line at a time.

Alternatively, you could use a third-party library which makes it simpler, such as Guava:

File file = new File("foo.txt");
List<String> lines = Files.readLines(file, Charsets.UTF_8);

Or if you're using Java 7, it's already available for you in java.nio.file.Files:

Path path = FileSystems.getDefault().getPath("foo.txt");
List<String> lines = Files.readAllLines(path, StandardCharsets.UTF_8);

回答2:

And as per your question for reading a text file you should use BufferedReader because Scanner hides IOException while BufferedReader throws it immediately.

BufferedReader is synchronized and Scanner is not.

Scanner is used for parsing tokens from the contents of the stream.

BufferedReader just reads the stream.

For more info follow the link (http://en.allexperts.com/q/Java-1046/2009/2/Difference-Scanner-Method-Buffered.htm)