ZipInputStream

Class Overview

Used to read (decompress) the data from zip files.

A zip file (or "archive") is a collection of (possibly) compressed files. When reading from a ZipInputStream, you call getNextEntry() which returns a ZipEntry of metadata corresponding to the userdata that follows. When you appear to have hit the end of this stream (which is really just the end of the current entry's userdata), call getNextEntry again. When it returns null, there are no more entries in the input file.

Although InflaterInputStream can only read compressed zip entries, this class can read non-compressed entries as well.

Use ZipFile if you need random access to entries by name, but use this class if you just want to iterate over all entries.

Example

Using ZipInputStream is a little more complicated than GZIPInputStream because zip files are containers that can contain multiple files. This code pulls all the files out of a zip file, similar to the unzip(1) utility.

 InputStream is = ...
 ZipInputStream zis = new ZipInputStream(new BufferedInputStream(is));
 try {
     ZipEntry ze;
     while ((ze = zis.getNextEntry()) != null) {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         byte[] buffer = new byte[1024];
         int count;
         while ((count = zis.read(buffer)) != -1) {
             baos.write(buffer, 0, count);
         }
         String filename = ze.getName();
         byte[] bytes = baos.toByteArray();
         // do something with 'filename' and 'bytes'...
     }
 } finally {
     zis.close();
 }
 

Summary

[Expand] Inherited Fields
From class java.util.zip.InflaterInputStream protected byte[] buf The input buffer used for decompression. protected Inflater inf The inflater used for this stream. protected int len The length of the buffer.
From class java.io.FilterInputStream protected InputStream in The source input stream that is filtered.

[Expand] Inherited Methods
From class java.util.zip.InflaterInputStream int available() Returns 0 when when this stream has exhausted its input; and 1 otherwise. void close() Closes the input stream. void fill() Fills the input buffer with data to be decompressed. void mark(int readlimit) Marks the current position in the stream. boolean markSupported() Returns whether the receiver implements mark semantics. int read() Reads a single byte of decompressed data. int read(byte[] buffer, int byteOffset, int byteCount) Reads up to byteCount bytes of decompressed data and stores it in buffer starting at byteOffset. void reset() This operation is not supported and throws IOException. long skip(long byteCount) Skips up to byteCount bytes of uncompressed data.
From class java.io.FilterInputStream int available() Returns an estimated number of bytes that can be read or skipped without blocking for more input. void close() Closes this stream. synchronized void mark(int readlimit) Sets a mark position in this stream. boolean markSupported() Indicates whether this stream supports mark() and reset(). int read() Reads a single byte from the filtered stream and returns it as an integer in the range from 0 to 255. int read(byte[] buffer, int byteOffset, int byteCount) Reads up to byteCount bytes from this stream and stores them in the byte array buffer starting at byteOffset. synchronized void reset() Resets this stream to the last marked location. long skip(long byteCount) Skips byteCount bytes in this stream.
From class java.io.InputStream int available() Returns an estimated number of bytes that can be read or skipped without blocking for more input. void close() Closes this stream. void mark(int readlimit) Sets a mark position in this InputStream. boolean markSupported() Indicates whether this stream supports the mark() and reset() methods. int read(byte[] buffer) Equivalent to read(buffer, 0, buffer.length). abstract int read() Reads a single byte from this stream and returns it as an integer in the range from 0 to 255. int read(byte[] buffer, int byteOffset, int byteCount) Reads up to byteCount bytes from this stream and stores them in the byte array buffer starting at byteOffset. synchronized void reset() Resets this stream to the last marked location. long skip(long byteCount) Skips at most byteCount bytes in this stream.
From class java.lang.Object Object clone() Creates and returns a copy of this Object. boolean equals(Object o) Compares this instance with the specified object and indicates if they are equal. void finalize() Invoked when the garbage collector has detected that this instance is no longer reachable. final Class<?> getClass() Returns the unique instance of Class that represents this object's class. int hashCode() Returns an integer hash code for this object. final void notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up. final void notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up. String toString() Returns a string containing a concise, human-readable description of this object. final void wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object. final void wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires. final void wait(long millis) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
From interface java.io.Closeable abstract void close() Closes the object and release any system resources it holds.
From interface java.lang.AutoCloseable abstract void close() Closes the object and release any system resources it holds.