Programming Tutorials

(追記) (追記ここまで)

SequenceInputStream example program in Java

By: Reema sen in Java Tutorials on 2022年09月15日 [フレーム]

The SequenceInputStream class allows you to concatenate multiple InputStreams. The construction of a SequenceInputStream is different from any other InputStream. A SequenceInputStream constructor uses either a pair of InputStreams or an Enumeration of InputStreams as its argument:

SequenceInputStream(InputStream first, InputStream second)
SequenceInputStream(Enumeration streamEnum)

Here is a sample program

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
public class SequenceInputStreamDemo {
 public static void main(String[] args) throws IOException {
 int c;
 List<String> files = new ArrayList<>();
 files.add("/autoexec.bat");
 files.add("/config.sys");
 InputStream input = sequenceInputStreamFromFiles(files);
 while ((c = input.read()) != -1) {
 System.out.print((char) c);
 }
 input.close();
 }
 private static InputStream sequenceInputStreamFromFiles(List<String> files) throws IOException {
 List<InputStream> inputStreams = new ArrayList<>();
 for (String file : files) {
 inputStreams.add(new FileInputStream(file));
 }
 return new SequenceInputStream(inputStreams.stream());
 }
}

The code demonstrates the use of SequenceInputStream to combine multiple input streams into a single, sequenced input stream.

The InputStreamEnumerator class is an implementation of Enumeration, which is used to iterate over a collection of objects. In this case, it is used to iterate over a Vector of file names and return an InputStream for each file.

The SequenceInputStreamDemo class creates a Vector of file names (/autoexec.bat and /config.sys), creates an InputStreamEnumerator object to iterate over the file names and return an InputStream for each file, and then passes the InputStreamEnumerator object to a SequenceInputStream object. The resulting InputStream combines the individual input streams into a single, sequenced input stream.

The code then reads from the InputStream one character at a time, printing each character to the console, until the end of the stream is reached. Finally, the InputStream is closed.

Previous
<< Providers in J2EE Deployment

Next
FileReader and FileWriter example program in Java>>

(追記) (追記ここまで)