#

| Chapter 31 The java.util.zip Package |

## 31.3 java.util.zip.CheckedOutputStream (JDK 1.1)

###

This class is a subclass of `java.io.FilterOutputStream` that allows data to be written to a stream and a checksum computed on that data at the same time.

To create a `CheckedOutputStream` you must specify the output stream that it is to write its data to, and you must also specify a `Checksum` object, such as an instance of `Adler32`, that implements the particular checksum algorithm you desire. The `write()` methods are similar to those of other `OutputStream` classes. The `getChecksum()` method returns the `Checksum` object. Note that you must call `getValue()` on this object in order to obtain the actual checksum value.

    public class CheckedOutputStream extends FilterOutputStream {
        // Public Constructor
                public CheckedOutputStream(OutputStream out, Checksum cksum);
        // Public Instance Methods
                public Checksum getChecksum();
                public void write(int b) throws IOException;  // Overrides FilterOutputStream
                public void write(byte[] b, int off, int len) throws IOException;  // Overrides FilterOutputStream
    }

### Hierarchy:

Object->OutputStream->FilterOutputStream->CheckedOutputStream

java.util.zip.CheckedInputStream (JDK 1.1) |  | java.util.zip.Checksum (JDK 1.1)