ZipInputStream

Class Overview

This class provides an implementation of FilterInputStream that decompresses data from an InputStream containing a ZIP archive.

A ZIP archive is a collection of (possibly) compressed files. When reading from a ZipInputStream, you retrieve the entry's metadata with getNextEntry before you can read the userdata.

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

Use ZipFile if you can access the archive as a file directly, especially if you want random access to entries, rather than needing to iterate over all entries.

Example

Using ZipInputStream is a little more complicated than GZIPInputStream because ZIP archives are containers that can contain multiple files. This code pulls all the files out of a ZIP archive, 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 offset, int byteCount) Reads up to byteCount bytes of decompressed data and stores it in buffer starting at offset. void reset() Reset the position of the stream to the last marked position. 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 offset, int count) Reads at most count bytes from this stream and stores them in the byte array buffer starting at offset. 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 offset, int length) Reads at most length bytes from this stream and stores them in the byte array b starting at offset. synchronized void reset() Resets this stream to the last marked location. long skip(long byteCount) Skips at most n 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.