testbytearrayoutputstream.java

本书是一本为Java学习者在基础内容学习结束后进行课程设计时提供参考的指导书

package apibook.c3.s7;

import java.io.*;
import java.util.zip.*;

//
public class TestByteArrayOutputStream {
  public TestByteArrayOutputStream() {
  }
  public static void main(String[] args) {
    try {
        FileInputStream in = new FileInputStream(args[0]);

        // Create compressed stream that writes to byte array output stream
        ByteArrayOutputStream b = new ByteArrayOutputStream();
        GZIPOutputStream out = new GZIPOutputStream(b);

        byte[] buf = new byte[512];
        int howmany;
        while ((howmany = in.read(buf)) > 0) {
            out.write(buf, 0, howmany);
        }
        in.close();
        out.flush();
        byte[] compressedBytes = b.toByteArray(); // get byte array
        b.writeTo(new FileOutputStream(args[1])); // write to file
        out.close();                              // closes both out and b
        System.out.println("compressed size: " + compressedBytes.length);
        // ... do something with byte array

    } catch (IOException e) {
        System.out.println(e);
    }
  }

}