Java IO Learning (21) FileReader and FileWriter

FileReader and FileWriter Source analysis

1. FileReader source code (based on jdk1.7.40)

Package java.io;
     
public class FileReader extends InputStreamReader {public
     
    filereader (String fileName) throws FileNotFoundException {
        Super (new FileInputStream (fil Java IO Series 21 inputstreamreader and Outputstreamwriterename));
    }
     
    Public filereader (file file) throws FileNotFoundException {
        super (new FileInputStream (file));
    }
     
    Public FileReader (FileDescriptor FD) {
        super (new FileInputStream (FD));
    }

From this, we can see that FileReader is based on inputstreamreader implementation.

2. FileWriter source code (based on jdk1.7.40)

Package java.io;
     
public class FileWriter extends OutputStreamWriter {public
     
    FileWriter (String fileName) throws IOException {
        Super (New FileOutputStream (FileName));
    }
     
    Public FileWriter (String filename, Boolean append) throws IOException {
        Super, new FileOutputStream (filename, append ));
    }
     
    Public FileWriter (file file) throws IOException {
        super (new FileOutputStream (file));
    }
     
    Public FileWriter (File file, Boolean append) throws IOException {
        super (new FileOutputStream (file, append));
    Public
     
    FileWriter (FileDescriptor fd) {
        super (new FileOutputStream (FD));
    }

From this, we can see that FileWriter is based on outputstreamwriter implementation.

Sample Programs

Import Java.io.File;
Import Java.io.FileInputStream;
Import Java.io.FileOutputStream;
import Java.io.FileWriter;;
Import Java.io.FileReader;
     
Import java.io.IOException;  /** * FileReader and FileWriter Test program * * @author Skywang/public class Filereaderwritertest {private static
    Final String FileName = "file.txt";
     
    private static final String CharsetName = "Utf-8";
        public static void Main (string[] args) {testwrite ();
    Testread ();
            }/** * OutputStreamWriter demo function * */private static void Testwrite () {try {
            Create the file "file.txt" corresponding to the files object File File = new file (FileName);
			Create FileOutputStream corresponds to FileWriter: Converts a stream of bytes into character streams, where data written to OUT1 is automatically converted to characters by Byte. See more highlights of this column: Http://www.bianceng.cnhttp://www.bianceng.cn/Programming/Java/FileWriter out1 = new FileWriter
            (file);
            Writes 10 Kanji out1.write ("Byte flow is example of character stream");
    Write to "0123456789" + newline character in "file"        Out1.write ("0123456789\n");
     
        Out1.close ();
        catch (IOException e) {e.printstacktrace ();
            }/** * InputStreamReader demo/private static void Testread () {try {
            Method 1: New FileInputStream object//New file "file.txt" corresponds to the file object, File File = new (FileName);
     
            FileReader in1 = new FileReader (file);
            Test read (), which reads a char C1 = (char) in1.read ();
     
            System.out.println ("c1=" +c1);
     
            Test Skip (Long ByteCount), skipping 4 characters in1.skip (6);
            Test read (char[] cbuf, int off, int len) char[] buf = new CHAR[10];
            In1.read (buf, 0, buf.length);
     
            System.out.println ("buf=" + (new String (BUF));
        In1.close ();
        catch (IOException e) {e.printstacktrace (); }
    }
}

Run Result:

c1= Word

buf= Flow Example 0123456

Source: http://www.cnblogs.com/skywang12345/p/io_22.html