About Sound File
sun.audio.NativeAudioStream class
throw an InvalidAudioFormatException to convert .wav and .aiff file
to .au audio file.
.au = sun audio file refers to 8-bit, 8,000 Hz, ulaw ( compounded
format) encoded audio file.
About Project
Stream
FileDialog
the java.awt contains a specialized
dialog class, it inherits form Dialog class.
Constructors
FlieDialog ( Frame, String )
import java.io.FileInputStream;
to perform file processing in java, the package java.io must be
imported.
Example
static public File get_dir(Frame f) {
FileDialog dialog = new FileDialog(f, "select file");
dialog.show();
String file_name = dialog.getFile();
String dir_name = dialog.getDirectory();
System.out.println("dir:" + dir_name + "file:"+file_name);
dialog.dispose();
return new File(dir_name);
}
FlieDialog fd = new FileDialog ( this, "Open a File" );
//Open a File is the title of the dialog box
The static constants FileDialog.SAVE
and FileDialog.LOAD specify the type of file dialog to create.
int = FileDialog.SAVE
int = FileDialog.LOAD
java.io creating file stream for input
and output, InputStream and OutputStream created use and detect
the end of filter input stream.
The stream associated with stream object
( system.in/system.out/system.err ) as a pipe
A pipe == A uninterpreted stream of bytes used to communicate between:
Program #1 ------------------ Program #2
Program ---------------------- file
Program --------------------- Device
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----------SIS----------- |
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----------SOS---------- |
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----------FIS----------- |
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----------FOS---------- |
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FileInputStream
New Class
FileInputStream inputfile = new FileInputStream ( "in.dat" ); in.dat is file specification
Example
Filespec ( "Pub/i/wow/in.dat" );
Example
static public File get_file(Frame f) {
FileDialog dialog = new FileDialog(f, "select file");
dialog.show();
String file_name = dialog.getFile();
String dir_name = dialog.getDirectory();
System.out.println("dir:" + dir_name + "file:"+file_name);
dialog.dispose();
return new File(file_name);
}
FileInputStream input_stream = new FileInputStream(input_name);
StreamTokenizer tokens = new StreamTokenizer(input_stream);
FileOutputStream output_stream = new FileOutputStream(output_name);
PrintStream output = new PrintStream(output_stream);
StreamTokenizer
To read number and string, convert a FileInputStream instance into a StreamTokenizer instance.
static public void list_filtered_href_file(String file) {
System.out.println("processing:\t" + file);
try {
FileInputStream input_file = new
FileInputStream(file);
StreamTokenizer tokens = new StreamTokenizer(input_file);
int next = 0;
tokens.resetSyntax();
tokens.wordChars(0,255);
tokens.quoteChar('"');
while ((next = tokens.nextToken()) != tokens.TT_EOF)
{
switch (next) {
case '"':
System.out.print('"');
StringTokenizer st =
new StringTokenizer(tokens.sval," ");
while (st.hasMoreTokens()) {
System.out.print(st.nextToken());
if (st.countTokens() > 1)
{System.out.print("%20");}
}
System.out.print('"');
break;
case tokens.TT_WORD:
System.out.print(tokens.sval+" ");
break;
case tokens.TT_NUMBER:
System.out.print(tokens.nval+" ");
break;
case tokens.TT_EOL:
System.out.println();
break;
}
}
System.out.println();
input_file.close();
}
catch (Exception exe)
{System.out.println("list_filtered_href_file:er!");}
}
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in file |
The first time token.nextToken( ); is called the first token is loaded.
Numbers a loaded into token.aval, a double.
Example
while ((next = tokens.nextToken()) != tokens.TT_EOF)
{
switch (next) {
case '"':
System.out.print('"');
StringTokenizer st =
new StringTokenizer(tokens.sval," ");
while (st.hasMoreTokens()) {
System.out.print(st.nextToken());
if (st.countTokens() > 1)
{System.out.print("%20");}
}
System.out.print('"');
break;
1. System.out is:
a. A printout of system file
b. Standard output stream
c. File output stream
d. A subclass of FileOutputStream
Last
Update: 04/09/97
Copyright © 1997- Douglas Lyon
Lyon@cse.bridgeport.edu