de.weltraumschaf.commons.validate

Class Validate

java.lang.Object

de.weltraumschaf.commons.validate.Validate

public final class Validate
extends Object

Provides methods to validate inputs.

Since:

1.0.0

Version:

$Id: $Id

Author:

Sven Strittmatter <weltraumschaf@googlemail.com>

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Validate() Hidden for pure static class.

Method Summary

Modifier and Type	Method and Description
private static String	badElementIndex(int index, int size, String desc) TODO: Review this method.
private static String	badPositionIndex(int index, int size, String desc) TODO Write comment
private static String	badPositionIndexes(int start, int end, int size) TODO Write comment
static int	checkElementIndex(int index, int size) Ensures that index specifies a valid element in an array, list or string of size size.
static int	checkElementIndex(int index, int size, String desc) Ensures that index specifies a valid element in an array, list or string of size size.
static void	checkPositionIndexes(int start, int end, int size) Ensures that start and end specify a valid positions in an array, list or string of size size, and are in order.
(package private) static String	format(String template, Object... args) Substitutes each %s in template with an argument.
static int	greaterThan(int reference, int lowerBound) Convenience method for greaterThan(int, int, java.lang.String) with null as name.
static int	greaterThan(int reference, int lowerBound, String name) Tests that a given integer reference value is greater than the given lower bound.
static long	greaterThan(long reference, long lowerBound) Convenience method for greaterThan(long, long, java.lang.String) with null as name.
static long	greaterThan(long reference, long lowerBound, String name) Tests that a given integer reference value is greater than the given lower bound.
static int	greaterThanOrEqual(int reference, int lowerBound) Convenience method for greaterThanOrEqual(int, int, java.lang.String) with null as name.
static int	greaterThanOrEqual(int reference, int lowerBound, String name) Tests that a given integer reference value is greater than or equal the given lower bound.
static long	greaterThanOrEqual(long reference, long lowerBound) Convenience method for greaterThanOrEqual(long, long, java.lang.String) with null as name.
static long	greaterThanOrEqual(long reference, long lowerBound, String name) Tests that a given integer reference value is greater than or equal the given lower bound.
static void	isTrue(boolean expression, String message) Tests that a given expression is true.
static String	notEmpty(String reference) Convenience message for notEmpty(java.lang.String, java.lang.String) with null as second parameter.
static String	notEmpty(String reference, String name) Validates that a given string reference is not null or empty.
static <T> T	notNull(T reference) Convenience message for notNull(java.lang.Object, java.lang.String) with null as second parameter.
static <T> T	notNull(T reference, String name) Validates that a given reference is not null.

Methods inherited from class java.lang.Object

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

Constructor Detail

Validate

private Validate()

Hidden for pure static class.

Method Detail

notNull

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

Validates that a given reference is not null.

This example validates that input is not null. If it is null a NullPointerException will be thrown with the name as hint in the exception message.:

 void someMethod(final Object input) {
     final Object validInput = Validate.notNull(input, "input");
     // ...
 }
 

The second parameter name may be omitted. Then a NullPointerException without any message will be thrown. For this purpose you can call the convenience method notNull(java.lang.Object).

Type Parameters:

T - type of reference

Parameters:

reference - validated reference

name - name of validated reference, may be null

Returns:

the reference, if it is valid

notNull

public static <T> T notNull(T reference)

Convenience message for notNull(java.lang.Object, java.lang.String) with null as second parameter.

Type Parameters:

T - type of reference

Parameters:

reference - validated reference

Returns:

the reference, if it is valid

notEmpty

public static String notEmpty(String reference,
                              String name)

Validates that a given string reference is not null or empty.

This example validates that input is not null. If it is null a NullPointerException will be thrown with the name as hint in the exception message. Also it validates that input is not empty by calling String.isEmpty(). If the string is empty an IllegalArgumentException will be thrown:

 void someMethod(final String input) {
     final Strign validInput = Validate.notEmpty(input, "input");
     // ...
 }
 

The second parameter name may be omitted. Then a NullPointerException or IllegalArgumentException without any message will be thrown. For this purpose you can call the convenience method notEmpty(java.lang.String).

Parameters:

reference - validated reference

name - name of validated reference, may be null

Returns:

the reference, if it is valid

notEmpty

public static String notEmpty(String reference)

Convenience message for notEmpty(java.lang.String, java.lang.String) with null as second parameter.

Parameters:

reference - validated reference

Returns:

the reference, if it is valid

greaterThan

public static int greaterThan(int reference,
                              int lowerBound,
                              String name)

Tests that a given integer reference value is greater than the given lower bound.

The method throws an IllegalArgumentException if the given reference is less than or equal the given lower bound value.

Parameters:

reference - validated reference

lowerBound - bound to test against

name - name of validated reference, may be null

Returns:

the reference, if it is valid

greaterThan

public static int greaterThan(int reference,
                              int lowerBound)

Convenience method for greaterThan(int, int, java.lang.String) with null as name.

Parameters:

reference - validated reference

lowerBound - bound to test against

Returns:

the reference, if it is valid

greaterThanOrEqual

public static int greaterThanOrEqual(int reference,
                                     int lowerBound,
                                     String name)

Tests that a given integer reference value is greater than or equal the given lower bound.

The method throws an IllegalArgumentException if the given reference is less than the given lower bound value.

Parameters:

reference - validated reference

lowerBound - bound to test against

name - name of validated reference, may be null

Returns:

the reference, if it is valid

greaterThanOrEqual

public static int greaterThanOrEqual(int reference,
                                     int lowerBound)

Convenience method for greaterThanOrEqual(int, int, java.lang.String) with null as name.

Parameters:

reference - validated reference

lowerBound - bound to test against

Returns:

the reference, if it is valid

greaterThan

public static long greaterThan(long reference,
                               long lowerBound,
                               String name)

Tests that a given integer reference value is greater than the given lower bound.

The method throws an IllegalArgumentException if the given reference is less than or equal the given lower bound value.

Parameters:

reference - validated reference

lowerBound - bound to test against

name - name of validated reference, may be null

Returns:

the reference, if it is valid

greaterThan

public static long greaterThan(long reference,
                               long lowerBound)

Convenience method for greaterThan(long, long, java.lang.String) with null as name.

Parameters:

reference - validated reference

lowerBound - bound to test against

Returns:

the reference, if it is valid

greaterThanOrEqual

public static long greaterThanOrEqual(long reference,
                                      long lowerBound,
                                      String name)

Tests that a given integer reference value is greater than or equal the given lower bound.

The method throws an IllegalArgumentException if the given reference is less than the given lower bound value.

Parameters:

reference - validated reference

lowerBound - bound to test against

name - name of validated reference, may be null

Returns:

the reference, if it is valid

greaterThanOrEqual

public static long greaterThanOrEqual(long reference,
                                      long lowerBound)

Convenience method for greaterThanOrEqual(long, long, java.lang.String) with null as name.

Parameters:

reference - validated reference

lowerBound - bound to test against

Returns:

the reference, if it is valid

isTrue

public static void isTrue(boolean expression,
                          String message)

Tests that a given expression is true.

Throws an IllegalArgumentException if the expression is false.

Parameters:

expression - tested expression

message - must not be null or empty

checkElementIndex

public static int checkElementIndex(int index,
                                    int size)

Ensures that index specifies a valid element in an array, list or string of size size. An element index may range from zero, inclusive, to size, exclusive. TODO: Review this method.

Parameters:

index - a user-supplied index identifying an element of an array, list or string

size - the size of that array, list or string

Returns:

the value of index

Throws:

IndexOutOfBoundsException - if index is negative or is not less than size

IllegalArgumentException - if size is negative

Since:

2.0

checkElementIndex

public static int checkElementIndex(int index,
                                    int size,
                                    String desc)

Ensures that index specifies a valid element in an array, list or string of size size. An element index may range from zero, inclusive, to size, exclusive. TODO: Review this method.

Parameters:

index - a user-supplied index identifying an element of an array, list or string

size - the size of that array, list or string

desc - the text to use to describe this index in an error message

Returns:

the value of index

Throws:

IndexOutOfBoundsException - if index is negative or is not less than size

IllegalArgumentException - if size is negative

Since:

2.0

badElementIndex

private static String badElementIndex(int index,
                                      int size,
                                      String desc)

TODO: Review this method.

Parameters:

index - TODO Write comment

size - TODO Write comment

desc - TODO Write comment

Returns:

TODO Write comment

Since:

2.0

format

static String format(String template,
                     Object... args)

Substitutes each %s in template with an argument. These are matched by position - the first %s gets args[0], etc. If there are more arguments than placeholders, the unmatched arguments will be appended to the end of the formatted message in square braces. TODO: Review this method.

Parameters:

template - a non-null string containing 0 or more %s placeholders.

args - the arguments to be substituted into the message template. Arguments are converted to strings using String.valueOf(Object). Arguments can be null.

checkPositionIndexes

public static void checkPositionIndexes(int start,
                                        int end,
                                        int size)

Ensures that start and end specify a valid positions in an array, list or string of size size, and are in order. A position index may range from zero to size, inclusive. TODO: Review this method.

Parameters:

start - a user-supplied index identifying a starting position in an array, list or string

end - a user-supplied index identifying a ending position in an array, list or string

size - the size of that array, list or string

Throws:

IndexOutOfBoundsException - if either index is negative or is greater than size, or if end is less than start

IllegalArgumentException - if size is negative

Since:

2.0

badPositionIndexes

private static String badPositionIndexes(int start,
                                         int end,
                                         int size)

TODO Write comment

Parameters:

start - TODO Write comment

end - TODO Write comment

size - TODO Write comment

Returns:

TODO Write comment

Since:

2.0

badPositionIndex

private static String badPositionIndex(int index,
                                       int size,
                                       String desc)

TODO Write comment

Parameters:

index - TODO Write comment

size - TODO Write comment

desc - TODO Write comment

Returns:

TODO Write comment

Since:

2.0