org.apache.hadoop.lib.util
Class Check

java.lang.Object
  org.apache.hadoop.lib.util.Check

@InterfaceAudience.Private
public class Check
extends Object

Utility methods to check preconditions.

Commonly used for method arguments preconditions.

Constructor Summary

Check()

Method Summary

static int	ge0(int value, String name) Verifies an integer is greater or equal to zero.
static long	ge0(long value, String name) Verifies an long is greater or equal to zero.
static int	gt0(int value, String name) Verifies an integer is greater than zero.
static long	gt0(long value, String name) Verifies an long is greater than zero.
static String	notEmpty(String str, String name) Verifies a string is not NULL and not emtpy
static List<String>	notEmptyElements(List<String> list, String name) Verifies a string list is not NULL and not emtpy
static <T> T	notNull(T obj, String name) Verifies a variable is not NULL.
static <T> List<T>	notNullElements(List<T> list, String name) Verifies a list does not have any NULL elements.
static String	validIdentifier(String value, int maxLen, String name) Verifies a value is a valid identifier, [a-zA-z_][a-zA-Z0-9_\-]*, up to a maximum length.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Check

public Check()

Method Detail

notNull

public static <T> T notNull(T obj,
                            String name)

Verifies a variable is not NULL.

Parameters:

obj - the variable to check.

name - the name to use in the exception message.

Returns:

the variable.

Throws:

IllegalArgumentException - if the variable is NULL.

notNullElements

public static <T> List<T> notNullElements(List<T> list,
                                          String name)

Verifies a list does not have any NULL elements.

Parameters:

list - the list to check.

name - the name to use in the exception message.

Returns:

the list.

Throws:

IllegalArgumentException - if the list has NULL elements.

notEmpty

public static String notEmpty(String str,
                              String name)

Verifies a string is not NULL and not emtpy

Parameters:

str - the variable to check.

name - the name to use in the exception message.

Returns:

the variable.

Throws:

IllegalArgumentException - if the variable is NULL or empty.

notEmptyElements

public static List<String> notEmptyElements(List<String> list,
                                            String name)

Verifies a string list is not NULL and not emtpy

Parameters:

list - the list to check.

name - the name to use in the exception message.

Returns:

the variable.

Throws:

IllegalArgumentException - if the string list has NULL or empty elements.

validIdentifier

public static String validIdentifier(String value,
                                     int maxLen,
                                     String name)

Verifies a value is a valid identifier, [a-zA-z_][a-zA-Z0-9_\-]*, up to a maximum length.

Parameters:

value - string to check if it is a valid identifier.

maxLen - maximun length.

name - the name to use in the exception message.

Returns:

the value.

Throws:

IllegalArgumentException - if the string is not a valid identifier.

gt0

public static int gt0(int value,
                      String name)

Verifies an integer is greater than zero.

Parameters:

value - integer value.

name - the name to use in the exception message.

Returns:

the value.

Throws:

IllegalArgumentException - if the integer is zero or less.

gt0

public static long gt0(long value,
                       String name)

Verifies an long is greater than zero.

Parameters:

value - long value.

name - the name to use in the exception message.

Returns:

the value.

Throws:

IllegalArgumentException - if the long is zero or less.

ge0

public static int ge0(int value,
                      String name)

Verifies an integer is greater or equal to zero.

Parameters:

value - integer value.

name - the name to use in the exception message.

Returns:

the value.

Throws:

IllegalArgumentException - if the integer is greater or equal to zero.

ge0

public static long ge0(long value,
                       String name)

Verifies an long is greater or equal to zero.

Parameters:

value - integer value.

name - the name to use in the exception message.

Returns:

the value.

Throws:

IllegalArgumentException - if the long is greater or equal to zero.