Java Readers and Writers

Java String Constructors

public String(byte bytes[], int offset, int length, String encoding) throws UnsupportedEncodingException
 
public String(byte bytes[], String encoding) throws UnsupportedEncodingException

String s = new String(t, "8859-9");

Character Set Encodings

Character Set Encodings

1. FileReader: This class is used to read character files. Its read() methods are fairly low-level, allowing you to read single characters, the whole stream of characters, or a fixed number of characters. FileReaders are usually wrapped by higher-level objects such as BufferedReaders, which improve performance and provide more convenient ways to work with the data.
2. BufferedReader: This class is used to make lower-level Reader classes like FileReader more efficient and easier to use. Compared to FileReaders, BufferedReaders read relatively large chunks of data from a file at once and keep this data in a buffer. When you ask for the next character or line of data, it is retrieved from the buffer, which minimizes the number of times that time-intensive, file-read operations are performed. In addition, BufferedReader provides more convenient methods, such as readLine(), that allow you to get the next line of characters from a file.
3. FileWriter: This class is used to write to character files. Its write() methods allow you to write character(s) or strings to a file. FileWriters are usually wrapped by higher-level Writer objects, such as BufferedWriters or PrintWriters, which provide better performance and higher-level, more flexible methods to write data.
4. BufferedWriter: This class is used to make lower-level classes like FileWriters more efficient and easier to use. Compared to FileWriters, BufferedWriters write relatively large chunks of data to a file at once, minimizing the number of times that slow, file-writing operations are performed. The BufferedWriter class also provides a newLine() method to create platform-specific line separators automatically.
5. PrintWriter: This class has been enhanced significantly in Java 5. Because of newly created methods and constructors (like building a PrintWriter with a File or a String), you might find that you can use PrintWriter in places where you previously needed a Writer to be wrapped with a FileWriter and/or a BufferedWriter. New methods like format(), printf(), and append() make PrintWriters very flexible and powerful.