MD5Hash (Hadoop 1.2.2-SNAPSHOT API)

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

所有已实现的接口:

Comparable<MD5Hash>, Writable, WritableComparable<MD5Hash>
```
public class MD5Hash
extends Object
implements WritableComparable<MD5Hash>
```
A Writable for MD5 hash values.

嵌套类概要

嵌套类
限定符和类型类和说明

static class MD5Hash.Comparator
A WritableComparator optimized for MD5Hash keys.

嵌套类
限定符和类型	类和说明
`static class`	`MD5Hash.Comparator` A WritableComparator optimized for MD5Hash keys.

字段概要

字段
限定符和类型字段和说明

static int MD5_LEN

字段
限定符和类型	字段和说明
`static int`	`MD5_LEN`

构造器概要

构造器
构造器和说明
`MD5Hash()` Constructs an MD5Hash.
`MD5Hash(byte[] digest)` Constructs an MD5Hash with a specified value.
`MD5Hash(String hex)` Constructs an MD5Hash from a hex string.

方法概要

方法
限定符和类型	方法和说明
`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[] 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(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`.

从类继承的方法 java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- 字段详细资料
  - MD5_LEN
```
public static final int MD5_LEN
```
    另请参阅:
    常量字段值
- 构造器详细资料
  - MD5Hash
```
public MD5Hash()
```
    Constructs an MD5Hash.
  - MD5Hash
```
public MD5Hash(String hex)
```
    Constructs an MD5Hash from a hex string.
  - MD5Hash
```
public MD5Hash(byte[] digest)
```
    Constructs an MD5Hash with a specified value.
- 方法详细资料
  - readFields
```
public void readFields(DataInput in)
                throws IOException
```
    从接口复制的说明: Writable
    
    Deserialize the fields of this object from in.
    For efficiency, implementations should attempt to re-use storage in the existing object where possible.
    
    指定者:
    
    readFields 在接口中 Writable
    
    参数:
    in - DataInput to deseriablize this object from.
    
    抛出:
    
    IOException
  - read
```
public static MD5Hash read(DataInput in)
                    throws IOException
```
    Constructs, reads and returns an instance.
    
    抛出:
    
    IOException
  - write
```
public void write(DataOutput out)
           throws IOException
```
    从接口复制的说明: Writable
    
    Serialize the fields of this object to out.
    
    指定者:
    
    write 在接口中 Writable
    
    参数:
    out - DataOuput to serialize this object into.
    
    抛出:
    
    IOException
  - set
```
public void set(MD5Hash that)
```
    Copy the contents of another instance into this instance.
  - getDigest
```
public byte[] getDigest()
```
    Returns the digest bytes.
  - digest
```
public static MD5Hash digest(byte[] data)
```
    Construct a hash value for a byte array.
  - getDigester
```
public static MessageDigest getDigester()
```
    Create a thread local MD5 digester
  - digest
```
public static MD5Hash digest(InputStream in)
                      throws IOException
```
    Construct a hash value for the content from the InputStream.
    
    抛出:
    
    IOException
  - digest
```
public static MD5Hash digest(byte[] data,
             int start,
             int len)
```
    Construct a hash value for a byte array.
  - digest
```
public static MD5Hash digest(String string)
```
    Construct a hash value for a String.
  - digest
```
public static MD5Hash digest(UTF8 utf8)
```
    Construct a hash value for a String.
  - halfDigest
```
public long halfDigest()
```
    Construct a half-sized version of this MD5. Fits in a long
  - quarterDigest
```
public int quarterDigest()
```
    Return a 32-bit digest of the MD5.
    
    返回:
    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.
    
    覆盖:
    
    equals 在类中 Object
  - hashCode
```
public int hashCode()
```
    Returns a hash code value for this object. Only uses the first 4 bytes, since md5s are evenly distributed.
    
    覆盖:
    
    hashCode 在类中 Object
  - compareTo
```
public int compareTo(MD5Hash that)
```
    Compares this object with the specified object for order.
    
    指定者:
    
    compareTo 在接口中 Comparable<MD5Hash>
  - toString
```
public String toString()
```
    Returns a string representation of this object.
    
    覆盖:
    
    toString 在类中 Object
  - setDigest
```
public void setDigest(String hex)
```
    Sets the digest value from a hex string.

类 MD5Hash

嵌套类概要

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

MD5_LEN

构造器详细资料

MD5Hash

MD5Hash

MD5Hash

方法详细资料

readFields

read

write

set

getDigest

digest

getDigester

digest

digest

digest

digest

halfDigest

quarterDigest

equals

hashCode

compareTo

toString

setDigest