File Doc Category Size Date Package
CheckedOutputStream.java API Doc Android 1.5 API 3208 Wed May 06 22:41:02 BST 2009 java.util.zip

CheckedOutputStream

java.lang.Object
- java.io.OutputStream
  - java.io.FilterOutputStream

public class CheckedOutputStream extends FilterOutputStream

The {@code CheckedOutputStream} class is used to maintain a running checksum of all data written to a stream. The purpose of this checksum is to establish data integrity, by publishing the checksum to other parties wanting to read the non corrupted data.

since: Android 1.0

Fields Summary
private final Checksum
check
Constructors Summary
public CheckedOutputStream(OutputStream os, Checksum cs)
Constructs a new {@code CheckedOutputStream} on {@code OutputStream} {@code os}. The checksum is calculated using the algorithm implemented by {@code csum}.
param
os the output stream to calculate checksum for.
param
cs an entity implementing the checksum algorithm.
since
Android 1.0
super(os); check = cs;
Methods Summary
public java.util.zip.Checksum getChecksum()
Returns the checksum calculated on the stream read so far.
return
the updated checksum.
since
Android 1.0
return check;
public void write(int val)
Writes the specified byte to the underlying stream. The checksum is updated with {@code val}.
param
val the data value to written to the output stream.
throws
IOException if an IO error has occurred.
since
Android 1.0
out.write(val); check.update(val);
public void write(byte[] buf, int off, int nbytes)
Writes n bytes of data from {@code buf} starting at offset {@code off} to the underlying stream. The checksum is updated with the bytes written.
param
buf data written to the output stream.
param
off the offset to start reading the data from {@code buf} written to the output stream.
param
nbytes number of bytes to write to the output stream.
throws
IOException if an IO error has occurred.
since
Android 1.0
out.write(buf, off, nbytes); check.update(buf, off, nbytes);