MD5Hash (Apache Hadoop Main 3.3.6 API)

java.lang.Object
- org.apache.hadoop.io.MD5Hash

All Implemented Interfaces:: Comparable<MD5Hash>, Writable, WritableComparable<MD5Hash>

@InterfaceAudience.Public
 @InterfaceStability.Stable
public class MD5Hash
extends Object
implements WritableComparable<MD5Hash>

A Writable for MD5 hash values.

Field Summary

Fields
Modifier and Type Field and Description

static int MD5_LEN

Fields
Modifier and Type	Field and Description
`static int`	`MD5_LEN`

Constructor Summary

Constructors
Constructor and Description
`MD5Hash()` Constructs an MD5Hash.
`MD5Hash(byte[] digest)` Constructs an MD5Hash with a specified value.
`MD5Hash(String hex)` Constructs an MD5Hash from a hex string.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`compareTo(MD5Hash that)` Compares this object with the specified object for order.
`static MD5Hash`	`digest(byte[] data)` Construct a hash value for a byte array.
`static MD5Hash`	`digest(byte[][] dataArr, int start, int len)` Construct a hash value for an array of byte array.
`static MD5Hash`	`digest(byte[] data, int start, int len)` Construct a hash value for a byte array.
`static MD5Hash`	`digest(InputStream in)` Construct a hash value for the content from the InputStream.
`static MD5Hash`	`digest(String string)` Construct a hash value for a String.
`static MD5Hash`	`digest(org.apache.hadoop.io.UTF8 utf8)` Construct a hash value for a String.
`boolean`	`equals(Object o)` Returns true iff `o` is an MD5Hash whose digest contains the same values.
`byte[]`	`getDigest()` Returns the digest bytes.
`static MessageDigest`	`getDigester()` Create a thread local MD5 digester.
`long`	`halfDigest()` Construct a half-sized version of this MD5.
`int`	`hashCode()` Returns a hash code value for this object.
`int`	`quarterDigest()` Return a 32-bit digest of the MD5.
`static MD5Hash`	`read(DataInput in)` Constructs, reads and returns an instance.
`void`	`readFields(DataInput in)` Deserialize the fields of this object from `in`.
`void`	`set(MD5Hash that)` Copy the contents of another instance into this instance.
`void`	`setDigest(String hex)` Sets the digest value from a hex string.
`String`	`toString()` Returns a string representation of this object.
`void`	`write(DataOutput out)` Serialize the fields of this object to `out`.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - MD5_LEN
```
public static final int MD5_LEN
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - MD5Hash
```
public MD5Hash()
```
    Constructs an MD5Hash.
  - MD5Hash
```
public MD5Hash(String hex)
```
    Constructs an MD5Hash from a hex string.
    
    Parameters:
    
    hex - input hex.
  - MD5Hash
```
public MD5Hash(byte[] digest)
```
    Constructs an MD5Hash with a specified value.
    
    Parameters:
    
    digest - digest.
- Method Detail
  - readFields
```
public void readFields(DataInput in)
                throws IOException
```
    Description copied from interface: Writable
    
    Deserialize the fields of this object from in.
    For efficiency, implementations should attempt to re-use storage in the existing object where possible.
    
    Specified by:
    
    readFields in interface Writable
    
    Parameters:
    
    in - DataInput to deseriablize this object from.
    
    Throws:
    
    IOException - any other problem for readFields.
  - read
```
public static MD5Hash read(DataInput in)
                    throws IOException
```
    Constructs, reads and returns an instance.
    
    Parameters:
    
    in - in.
    
    Returns:
    
    MD5Hash.
    
    Throws:
    
    IOException - raised on errors performing I/O.
  - write
```
public void write(DataOutput out)
           throws IOException
```
    Description copied from interface: Writable
    
    Serialize the fields of this object to out.
    
    Specified by:
    
    write in interface Writable
    
    Parameters:
    
    out - DataOuput to serialize this object into.
    
    Throws:
    
    IOException - any other problem for write.
  - set
```
public void set(MD5Hash that)
```
    Copy the contents of another instance into this instance.
    
    Parameters:
    
    that - that.
  - getDigest
```
public byte[] getDigest()
```
    Returns the digest bytes.
    
    Returns:
    
    digest.
  - digest
```
public static MD5Hash digest(byte[] data)
```
    Construct a hash value for a byte array.
    
    Parameters:
    
    data - data.
    
    Returns:
    
    MD5Hash.
  - getDigester
```
public static MessageDigest getDigester()
```
    Create a thread local MD5 digester.
    
    Returns:
    
    MessageDigest.
  - digest
```
public static MD5Hash digest(InputStream in)
                      throws IOException
```
    Construct a hash value for the content from the InputStream.
    
    Parameters:
    
    in - input stream.
    
    Returns:
    
    MD5Hash.
    
    Throws:
    
    IOException - raised on errors performing I/O.
  - digest
```
public static MD5Hash digest(byte[] data,
                             int start,
                             int len)
```
    Construct a hash value for a byte array.
    
    Parameters:
    
    data - data.
    
    start - start.
    
    len - len.
    
    Returns:
    
    MD5Hash.
  - digest
```
public static MD5Hash digest(byte[][] dataArr,
                             int start,
                             int len)
```
    Construct a hash value for an array of byte array.
    
    Parameters:
    
    dataArr - dataArr.
    
    start - start.
    
    len - len.
    
    Returns:
    
    MD5Hash.
  - digest
```
public static MD5Hash digest(String string)
```
    Construct a hash value for a String.
    
    Parameters:
    
    string - string.
    
    Returns:
    
    MD5Hash.
  - digest
```
public static MD5Hash digest(org.apache.hadoop.io.UTF8 utf8)
```
    Construct a hash value for a String.
    
    Parameters:
    
    utf8 - utf8.
    
    Returns:
    
    MD5Hash.
  - halfDigest
```
public long halfDigest()
```
    Construct a half-sized version of this MD5. Fits in a long.
    
    Returns:
    
    halfDigest.
  - quarterDigest
```
public int quarterDigest()
```
    Return a 32-bit digest of the MD5.
    
    Returns:
    
    the first 4 bytes of the md5
  - equals
```
public boolean equals(Object o)
```
    Returns true iff o is an MD5Hash whose digest contains the same values.
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Returns a hash code value for this object. Only uses the first 4 bytes, since md5s are evenly distributed.
    
    Overrides:
    
    hashCode in class Object
  - compareTo
```
public int compareTo(MD5Hash that)
```
    Compares this object with the specified object for order.
    
    Specified by:
    
    compareTo in interface Comparable<MD5Hash>
  - toString
```
public String toString()
```
    Returns a string representation of this object.
    
    Overrides:
    
    toString in class Object
  - setDigest
```
public void setDigest(String hex)
```
    Sets the digest value from a hex string.
    
    Parameters:
    
    hex - hex.

Class MD5Hash

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MD5_LEN

Constructor Detail

MD5Hash

MD5Hash

MD5Hash

Method Detail

readFields

read

write

set

getDigest

digest

getDigester

digest

digest

digest

digest

digest

halfDigest

quarterDigest

equals

hashCode

compareTo

toString

setDigest