## org.apache.tools.ant.taskdefs
Class Checksum

    java.lang.Object
      org.apache.tools.ant.ProjectComponent
          org.apache.tools.ant.Task
              org.apache.tools.ant.taskdefs.MatchingTask
                  org.apache.tools.ant.taskdefs.Checksum

All Implemented Interfaces:
  java.lang.Cloneable, Condition, SelectorContainer

    public class Checksum

extends MatchingTask
implements Condition

Used to create or verify file checksums.

Since:
  Ant 1.5

Nested Class Summary
`static class` `Checksum.FormatElement` Helper class for the format attribute.

Field Summary

Fields inherited from class org.apache.tools.ant.taskdefs.MatchingTask
`fileset`

Fields inherited from class org.apache.tools.ant.Task
`target, taskName, taskType, wrapper`

Fields inherited from class org.apache.tools.ant.ProjectComponent
`description, location, project`

Constructor Summary
`Checksum()`

Method Summary
`void` `add(ResourceCollection rc)` Add a resource collection.
`void` `addFileset(FileSet set)` Files to generate checksums for.
`static byte[]` `decodeHex(char[] data)` Converts an array of characters representing hexadecimal values into an array of bytes of those same values.
`boolean` `eval()` Calculate the checksum(s)
`void` `execute()` Calculate the checksum(s).
`void` `setAlgorithm(java.lang.String algorithm)` Specifies the algorithm to be used to compute the checksum.
`void` `setFile(java.io.File file)` Sets the file for which the checksum is to be calculated.
`void` `setFileext(java.lang.String fileext)` Sets the file extension that is be to used to create or identify destination file.
`void` `setForceOverwrite(boolean forceOverwrite)` Whether or not to overwrite existing file irrespective of whether it is newer than the source file.
`void` `setFormat(Checksum.FormatElement e)` Select the in/output pattern via a well know format name.
`void` `setPattern(java.lang.String p)` Specify the pattern to use as a MessageFormat pattern.
`void` `setProperty(java.lang.String property)` Sets the property to hold the generated checksum.
`void` `setProvider(java.lang.String provider)` Sets the MessageDigest algorithm provider to be used to calculate the checksum.
`void` `setReadBufferSize(int size)` The size of the read buffer to use.
`void` `setTodir(java.io.File todir)` Sets the root directory where checksum files will be written/read
`void` `setTotalproperty(java.lang.String totalproperty)` Sets the property to hold the generated total checksum for all files.
`void` `setVerifyproperty(java.lang.String verifyProperty)` Sets the verify property.

Methods inherited from class org.apache.tools.ant.taskdefs.MatchingTask

`add, addAnd, addContains, addContainsRegexp, addCustom, addDate, addDepend, addDepth, addDifferent, addFilename, addMajority, addModified, addNone, addNot, addOr, addPresent, addSelector, addSize, addType, appendSelector, createExclude, createExcludesFile, createInclude, createIncludesFile, createPatternSet, getDirectoryScanner, getImplicitFileSet, getSelectors, hasSelectors, selectorCount, selectorElements, setCaseSensitive, setDefaultexcludes, setExcludes, setExcludesfile, setFollowSymlinks, setIncludes, setIncludesfile, setProject, XsetIgnore, XsetItems`

Methods inherited from class org.apache.tools.ant.Task
`bindToOwner, getOwningTarget, getRuntimeConfigurableWrapper, getTaskName, getTaskType, getWrapper, handleErrorFlush, handleErrorOutput, handleFlush, handleInput, handleOutput, init, isInvalid, log, log, log, log, maybeConfigure, perform, reconfigure, setOwningTarget, setRuntimeConfigurableWrapper, setTaskName, setTaskType`

Methods inherited from class org.apache.tools.ant.ProjectComponent
`clone, getDescription, getLocation, getProject, setDescription, setLocation`

Methods inherited from class java.lang.Object
`equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### Checksum

    public Checksum()

Method Detail

### setFile

    public void setFile(java.io.File file)

  Sets the file for which the checksum is to be calculated.

  Parameters:
    `file` - a `File` value

### setTodir

    public void setTodir(java.io.File todir)

  Sets the root directory where checksum files will be written/read

  Parameters:
    `todir` - the directory to write to
  Since:
    Ant 1.6

### setAlgorithm

    public void setAlgorithm(java.lang.String algorithm)

  Specifies the algorithm to be used to compute the checksum. Defaults to "MD5". Other popular algorithms like "SHA" may be used as well.

  Parameters:
    `algorithm` - a `String` value

### setProvider

    public void setProvider(java.lang.String provider)

  Sets the MessageDigest algorithm provider to be used to calculate the checksum.

  Parameters:
    `provider` - a `String` value

### setFileext

    public void setFileext(java.lang.String fileext)

  Sets the file extension that is be to used to create or identify destination file.

  Parameters:
    `fileext` - a `String` value

### setProperty

    public void setProperty(java.lang.String property)

  Sets the property to hold the generated checksum.

  Parameters:
    `property` - a `String` value

### setTotalproperty

    public void setTotalproperty(java.lang.String totalproperty)

  Sets the property to hold the generated total checksum for all files.

  Parameters:
    `totalproperty` - a `String` value
  Since:
    Ant 1.6

### setVerifyproperty

    public void setVerifyproperty(java.lang.String verifyProperty)

  Sets the verify property. This project property holds the result of a checksum verification - "true" or "false"

  Parameters:
    `verifyProperty` - a `String` value

### setForceOverwrite

    public void setForceOverwrite(boolean forceOverwrite)

  Whether or not to overwrite existing file irrespective of whether it is newer than the source file. Defaults to false.

  Parameters:
    `forceOverwrite` - a `boolean` value

### setReadBufferSize

    public void setReadBufferSize(int size)

  The size of the read buffer to use.

  Parameters:
    `size` - an `int` value

### setFormat

    public void setFormat(Checksum.FormatElement e)

  Select the in/output pattern via a well know format name.

  Parameters:
    `e` - an `enumerated` value
  Since:
    1.7.0

### setPattern

    public void setPattern(java.lang.String p)

  Specify the pattern to use as a MessageFormat pattern.

  {0} gets replaced by the checksum, {1} by the filename.

  Parameters:
    `p` - a `String` value
  Since:
    1.7.0

### addFileset

    public void addFileset(FileSet set)

  Files to generate checksums for.

  Parameters:
    `set` - a fileset of files to generate checksums for.

### add

    public void add(ResourceCollection rc)

  Add a resource collection.

  Parameters:
    `rc` - the ResourceCollection to add.

### execute

    public void execute()
                 throws BuildException

  Calculate the checksum(s).

  Overrides:
    `execute` in class `Task`
  Throws:
    `BuildException` - on error

### eval

    public boolean eval()
                 throws BuildException

  Calculate the checksum(s)

  Specified by:
    `eval` in interface `Condition`
  Returns:
    Returns true if the checksum verification test passed, false otherwise.
  Throws:
    `BuildException` - on error

### decodeHex

    public static byte[] decodeHex(char[] data)
                            throws BuildException

  Converts an array of characters representing hexadecimal values into an array of bytes of those same values. The returned array will be half the length of the passed array, as it takes two characters to represent any given byte. An exception is thrown if the passed char array has an odd number of elements. NOTE: This code is copied from jakarta-commons codec.

  Parameters:
    `data` - an array of characters representing hexadecimal values
  Returns:
    the converted array of bytes
  Throws:
    `BuildException` - on error