org.apache.commons.lang
Class Validate

java.lang.Object
  org.apache.commons.lang.Validate

public class Validate
extends Object

This class assists in validating arguments.

The class is based along the lines of JUnit. If an argument value is deemed invalid, an IllegalArgumentException is thrown. For example:

 Validate.isTrue( i > 0, "The value must be greater than zero: ", i);
 Validate.notNull( surname, "The surname must not be null");
 

Since:

2.0

Version:

$Id: Validate.java 905636 2010-02-02 14:03:32Z niallp $

Author:

Apache Software Foundation, Ola Berg, Gary Gregory, Norm Deane

Constructor Summary

Validate()
Constructor.

Method Summary

static void	allElementsOfType(Collection collection, Class clazz) Validate an argument, throwing IllegalArgumentException if the argument collection is null or has elements that are not of type clazz or a subclass.
static void	allElementsOfType(Collection collection, Class clazz, String message) Validate an argument, throwing IllegalArgumentException if the argument collection is null or has elements that are not of type clazz or a subclass.
static void	isTrue(boolean expression) Validate that the argument condition is true; otherwise throwing an exception.
static void	isTrue(boolean expression, String message) Validate that the argument condition is true; otherwise throwing an exception with the specified message.
static void	isTrue(boolean expression, String message, double value) Validate that the argument condition is true; otherwise throwing an exception with the specified message.
static void	isTrue(boolean expression, String message, long value) Validate that the argument condition is true; otherwise throwing an exception with the specified message.
static void	isTrue(boolean expression, String message, Object value) Validate that the argument condition is true; otherwise throwing an exception with the specified message.
static void	noNullElements(Collection collection) Validate that the specified argument collection is neither null nor contains any elements that are null; otherwise throwing an exception.
static void	noNullElements(Collection collection, String message) Validate that the specified argument collection is neither null nor contains any elements that are null; otherwise throwing an exception with the specified message.
static void	noNullElements(Object[] array) Validate that the specified argument array is neither null nor contains any elements that are null; otherwise throwing an exception.
static void	noNullElements(Object[] array, String message) Validate that the specified argument array is neither null nor contains any elements that are null; otherwise throwing an exception with the specified message.
static void	notEmpty(Collection collection) Validate that the specified argument collection is neither null nor a size of zero (no elements); otherwise throwing an exception.
static void	notEmpty(Collection collection, String message) Validate that the specified argument collection is neither null nor a size of zero (no elements); otherwise throwing an exception with the specified message.
static void	notEmpty(Map map) Validate that the specified argument map is neither null nor a size of zero (no elements); otherwise throwing an exception.
static void	notEmpty(Map map, String message) Validate that the specified argument map is neither null nor a size of zero (no elements); otherwise throwing an exception with the specified message.
static void	notEmpty(Object[] array) Validate that the specified argument array is neither null nor a length of zero (no elements); otherwise throwing an exception.
static void	notEmpty(Object[] array, String message) Validate that the specified argument array is neither null nor a length of zero (no elements); otherwise throwing an exception with the specified message.
static void	notEmpty(String string) Validate that the specified argument string is neither null nor a length of zero (no characters); otherwise throwing an exception with the specified message.
static void	notEmpty(String string, String message) Validate that the specified argument string is neither null nor a length of zero (no characters); otherwise throwing an exception with the specified message.
static void	notNull(Object object) Validate that the specified argument is not null; otherwise throwing an exception.
static void	notNull(Object object, String message) Validate that the specified argument is not null; otherwise throwing an exception with the specified message.

Methods inherited from class java.lang.Object

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

Constructor Detail

Validate

public Validate()

Constructor. This class should not normally be instantiated.

Method Detail

isTrue

public static void isTrue(boolean expression,
                          String message,
                          Object value)

Validate that the argument condition is true; otherwise throwing an exception with the specified message. This method is useful when validating according to an arbitrary boolean expression, such as validating an object or using your own custom validation expression.

Validate.isTrue( myObject.isOk(), "The object is not OK: ", myObject);

For performance reasons, the object value is passed as a separate parameter and appended to the exception message only in the case of an error.

Parameters:

expression - the boolean expression to check

message - the exception message if invalid

value - the value to append to the message when invalid

Throws:

IllegalArgumentException - if expression is false

isTrue

public static void isTrue(boolean expression,
                          String message,
                          long value)

Validate that the argument condition is true; otherwise throwing an exception with the specified message. This method is useful when validating according to an arbitrary boolean expression, such as validating a primitive number or using your own custom validation expression.

Validate.isTrue(i > 0.0, "The value must be greater than zero: ", i);

For performance reasons, the long value is passed as a separate parameter and appended to the exception message only in the case of an error.

Parameters:

expression - the boolean expression to check

message - the exception message if invalid

value - the value to append to the message when invalid

Throws:

IllegalArgumentException - if expression is false

isTrue

public static void isTrue(boolean expression,
                          String message,
                          double value)

Validate that the argument condition is true; otherwise throwing an exception with the specified message. This method is useful when validating according to an arbitrary boolean expression, such as validating a primitive number or using your own custom validation expression.

Validate.isTrue(d > 0.0, "The value must be greater than zero: ", d);

For performance reasons, the double value is passed as a separate parameter and appended to the exception message only in the case of an error.

Parameters:

expression - the boolean expression to check

message - the exception message if invalid

value - the value to append to the message when invalid

Throws:

IllegalArgumentException - if expression is false

isTrue

public static void isTrue(boolean expression,
                          String message)

Validate that the argument condition is true; otherwise throwing an exception with the specified message. This method is useful when validating according to an arbitrary boolean expression, such as validating a primitive number or using your own custom validation expression.

 Validate.isTrue( (i > 0), "The value must be greater than zero");
 Validate.isTrue( myObject.isOk(), "The object is not OK");
 

Parameters:

expression - the boolean expression to check

message - the exception message if invalid

Throws:

IllegalArgumentException - if expression is false

isTrue

public static void isTrue(boolean expression)

Validate that the argument condition is true; otherwise throwing an exception. This method is useful when validating according to an arbitrary boolean expression, such as validating a primitive number or using your own custom validation expression.

 Validate.isTrue(i > 0);
 Validate.isTrue(myObject.isOk());

The message of the exception is "The validated expression is false".

Parameters:

expression - the boolean expression to check

Throws:

IllegalArgumentException - if expression is false

notNull

public static void notNull(Object object)

Validate that the specified argument is not null; otherwise throwing an exception.

Validate.notNull(myObject);

The message of the exception is "The validated object is null".

Parameters:

object - the object to check

Throws:

IllegalArgumentException - if the object is null

notNull

public static void notNull(Object object,
                           String message)

Validate that the specified argument is not null; otherwise throwing an exception with the specified message.

Validate.notNull(myObject, "The object must not be null");

Parameters:

object - the object to check

message - the exception message if invalid

notEmpty

public static void notEmpty(Object[] array,
                            String message)

Validate that the specified argument array is neither null nor a length of zero (no elements); otherwise throwing an exception with the specified message.

Validate.notEmpty(myArray, "The array must not be empty");

Parameters:

array - the array to check

message - the exception message if invalid

Throws:

IllegalArgumentException - if the array is empty

notEmpty

public static void notEmpty(Object[] array)

Validate that the specified argument array is neither null nor a length of zero (no elements); otherwise throwing an exception.

Validate.notEmpty(myArray);

The message in the exception is "The validated array is empty".

Parameters:

array - the array to check

Throws:

IllegalArgumentException - if the array is empty

notEmpty

public static void notEmpty(Collection collection,
                            String message)

Validate that the specified argument collection is neither null nor a size of zero (no elements); otherwise throwing an exception with the specified message.

Validate.notEmpty(myCollection, "The collection must not be empty");

Parameters:

collection - the collection to check

message - the exception message if invalid

Throws:

IllegalArgumentException - if the collection is empty

notEmpty

public static void notEmpty(Collection collection)

Validate that the specified argument collection is neither null nor a size of zero (no elements); otherwise throwing an exception.

Validate.notEmpty(myCollection);

The message in the exception is "The validated collection is empty".

Parameters:

collection - the collection to check

Throws:

IllegalArgumentException - if the collection is empty

notEmpty

public static void notEmpty(Map map,
                            String message)

Validate that the specified argument map is neither null nor a size of zero (no elements); otherwise throwing an exception with the specified message.

Validate.notEmpty(myMap, "The map must not be empty");

Parameters:

map - the map to check

message - the exception message if invalid

Throws:

IllegalArgumentException - if the map is empty

notEmpty

public static void notEmpty(Map map)

Validate that the specified argument map is neither null nor a size of zero (no elements); otherwise throwing an exception.

Validate.notEmpty(myMap);

The message in the exception is "The validated map is empty".

Parameters:

map - the map to check

Throws:

IllegalArgumentException - if the map is empty

See Also:

#notEmpty(Map, String, Object...)

notEmpty

public static void notEmpty(String string,
                            String message)

Validate that the specified argument string is neither null nor a length of zero (no characters); otherwise throwing an exception with the specified message.

Validate.notEmpty(myString, "The string must not be empty");

Parameters:

string - the string to check

message - the exception message if invalid

Throws:

IllegalArgumentException - if the string is empty

notEmpty

public static void notEmpty(String string)

Validate that the specified argument string is neither null nor a length of zero (no characters); otherwise throwing an exception with the specified message.

Validate.notEmpty(myString);

The message in the exception is "The validated string is empty".

Parameters:

string - the string to check

Throws:

IllegalArgumentException - if the string is empty

noNullElements

public static void noNullElements(Object[] array,
                                  String message)

Validate that the specified argument array is neither null nor contains any elements that are null; otherwise throwing an exception with the specified message.

Validate.noNullElements(myArray, "The array contain null at position %d");

If the array is null, then the message in the exception is "The validated object is null".

Parameters:

array - the array to check

message - the exception message if the collection has null elements

Throws:

IllegalArgumentException - if the array is null or an element in the array is null

noNullElements

public static void noNullElements(Object[] array)

Validate that the specified argument array is neither null nor contains any elements that are null; otherwise throwing an exception.

Validate.noNullElements(myArray);

If the array is null, then the message in the exception is "The validated object is null".

If the array has a null element, then the message in the exception is "The validated array contains null element at index: " followed by the index.

Parameters:

array - the array to check

Throws:

IllegalArgumentException - if the array is null or an element in the array is null

noNullElements

public static void noNullElements(Collection collection,
                                  String message)

Validate that the specified argument collection is neither null nor contains any elements that are null; otherwise throwing an exception with the specified message.

Validate.noNullElements(myCollection, "The collection contains null elements");

If the collection is null, then the message in the exception is "The validated object is null".

Parameters:

collection - the collection to check

message - the exception message if the collection has

Throws:

IllegalArgumentException - if the collection is null or an element in the collection is null

noNullElements

public static void noNullElements(Collection collection)

Validate that the specified argument collection is neither null nor contains any elements that are null; otherwise throwing an exception.

Validate.noNullElements(myCollection);

If the collection is null, then the message in the exception is "The validated object is null".

If the collection has a null element, then the message in the exception is "The validated collection contains null element at index: " followed by the index.

Parameters:

collection - the collection to check

Throws:

IllegalArgumentException - if the collection is null or an element in the collection is null

allElementsOfType

public static void allElementsOfType(Collection collection,
                                     Class clazz,
                                     String message)

Validate an argument, throwing IllegalArgumentException if the argument collection is null or has elements that are not of type clazz or a subclass.

 Validate.allElementsOfType(collection, String.class, "Collection has invalid elements");
 

Parameters:

collection - the collection to check, not null

clazz - the Class which the collection's elements are expected to be, not null

message - the exception message if the Collection has elements not of type clazz

Since:

2.1

allElementsOfType

public static void allElementsOfType(Collection collection,
                                     Class clazz)

Validate an argument, throwing IllegalArgumentException if the argument collection is null or has elements that are not of type clazz or a subclass.

 Validate.allElementsOfType(collection, String.class);
 

The message in the exception is 'The validated collection contains an element not of type clazz at index: '.

Parameters:

collection - the collection to check, not null

clazz - the Class which the collection's elements are expected to be, not null

Since:

2.1