Package org.hansken.plugin.extraction.util

Class ArgChecks

java.lang.Object

org.hansken.plugin.extraction.util.ArgChecks

public final class ArgChecks
extends Object

A collection of methods for defensively checking arguments passed to methods.

Method Summary

Modifier and Type	Method	Description
static Object[]	argNotAllNull(String name, Object... values)	Check that not all values with given name are null, otherwise throw an exception.
static String	argNotEmpty(String name, String value)	Check that the string with given name is not null or empty, otherwise throw an exception.
static <T> Collection<T>	argNotEmpty(String name, Collection<T> value)	Check that the collection value with given name is not empty, otherwise throw an exception.
static <T> T[]	argNotEmpty(String name, T[] value)	Check that the array value with given name is not empty, otherwise throw an exception.
static float	argNotNegative(String name, float value)	Check that the float with given name is not negative, otherwise throw an exception.
static int	argNotNegative(String name, int value)	Check that the int with given name is not negative, otherwise throw an exception.
static long	argNotNegative(String name, long value)	Check that the long with given name is not negative, otherwise throw an exception.
static <T> T	argNotNull(String name, T value)	Check that the value with given name is not null, otherwise throw an exception.
static <T> List<T>	argsIsType(String name, List<T> value, Class<?> type)	Check that the value with given name is of type type, otherwise throw an exception.

Methods inherited from class java.lang.Object

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

Method Detail

argNotNull

public static <T> T argNotNull(String name,
                               T value)

Check that the value with given name is not null, otherwise throw an exception.

Example usage:

 
     private final Author author;

     public Book(final Author author) {
          // this throws a NullPointerException when the author is null
          this.author = argNotNull("author", author);
     }
 
 

Type Parameters:

T - the type of the value

Parameters:

name - a descriptive name for the value (most likely the argument name)

value - the value itself

Returns:

the value, so it can be used to inline in an assignment

Throws:

NullPointerException - if value == null

argsIsType

public static <T> List<T> argsIsType(String name,
                                     List<T> value,
                                     Class<?> type)

Check that the value with given name is of type type, otherwise throw an exception.

Example usage:

 
     public Book(final List<Object> authors) {
          // this throws a ClassCastException when authors contains a type other than Author.class
          argsIsType("author", authors, Author.class);
     }
 
 

Type Parameters:

T - the type of the value

Parameters:

name - a descriptive name for the value (most likely the argument name)

value - the value itself

type - the class type we want to check against value

Returns:

the value, so it can be used to inline in an assignment

Throws:

ClassCastException - if value.allMatch(type::isInstance) is false

argNotAllNull

public static Object[] argNotAllNull(String name,
                                     Object... values)

Check that not all values with given name are null, otherwise throw an exception.

Example usage:

 
     private final Author author;

     public Book(final Author... authors) {
          // this throws a NullPointerException when the author is null
          this.author = argNotAllNull("authors", authors);
     }
 
 

Parameters:

name - a descriptive name for the values (most likely the argument name)

values - the values, which can be different types

Returns:

the values, so it can be used to inline in an assignment

Throws:

NullPointerException - if values.allMatch(Objects::isNull)

argNotEmpty

public static <T> T[] argNotEmpty(String name,
                                  T[] value)

Check that the array value with given name is not empty, otherwise throw an exception.

Example usage:

 
     private final Author[] author;

     public Book(final Author[] author) {
          // this throws a NullPointerException when the author array is empty
          this.author = argNotEmpty("author", author);
     }
 
 

Type Parameters:

T - the type of the value

Parameters:

name - a descriptive name for the value (most likely the argument name)

value - the value itself

Returns:

the value, so it can be used to inline in an assignment

Throws:

IllegalArgumentException - if value == null || value.length == 0

argNotEmpty

public static <T> Collection<T> argNotEmpty(String name,
                                            Collection<T> value)

Check that the collection value with given name is not empty, otherwise throw an exception.

Example usage:

 
     private final Collection<Author> author;

     public Book(final Collection<Author> author) {
          // this throws a NullPointerException when the author collection is empty
          this.author = argNotEmpty("author", author);
     }
 
 

Type Parameters:

T - the type of the value

Parameters:

name - a descriptive name for the value (most likely the argument name)

value - the value itself

Returns:

the value, so it can be used to inline in an assignment

Throws:

IllegalArgumentException - if value == null || value.isEmpty()

argNotEmpty

public static String argNotEmpty(String name,
                                 String value)

Check that the string with given name is not null or empty, otherwise throw an exception.

Example usage:

 
     private final String title;

     public Book(final String title) {
          // this throws a NullPointerException when the author is null
          // or an IllegalArgumentException when author is an empty String
          this.title = argNotEmpty("title", title);
     }
 
 

Parameters:

name - a descriptive name for the string (most likely the argument name)

value - the string itself

Returns:

the string, so it can be used to inline in an assignment

Throws:

NullPointerException - if value == null

IllegalArgumentException - if value.isEmpty()

argNotNegative

public static int argNotNegative(String name,
                                 int value)

Check that the int with given name is not negative, otherwise throw an exception. Example usage:

 
     private final int pageCount;

     public Book(final int pageCount) {
          // this throws an IllegalArgumentException when pageCount is negative
          this.pageCount = argNotNegative("pageCount", pageCount);
     }
 
 

Parameters:

name - a descriptive name for the int (most likely the argument name)

value - the int itself

Returns:

the int, so it can be used in an inline assignment

Throws:

IllegalArgumentException - if value < 0

argNotNegative

public static long argNotNegative(String name,
                                  long value)

Check that the long with given name is not negative, otherwise throw an exception. Example usage:

 
     private final long pageCount;

     public Book(final long pageCount) {
          // this throws an IllegalArgumentException when pageCount is negative
          this.pageCount = argNotNegative("pageCount", pageCount);
     }
 
 

Parameters:

name - a descriptive name for the long (most likely the argument name)

value - the long itself

Returns:

the long, so it can be used in an inline assignment

Throws:

IllegalArgumentException - if value < 0

argNotNegative

public static float argNotNegative(String name,
                                   float value)

Check that the float with given name is not negative, otherwise throw an exception. Example usage:

 
     private final float pageCount;

     public Book(final float pageCount) {
          // this throws an IllegalArgumentException when pageCount is negative
          this.pageCount = argNotNegative("pageCount", pageCount);
     }
 
 

Parameters:

name - a descriptive name for the float (most likely the argument name)

value - the float itself

Returns:

the float, so it can be used in an inline assignment

Throws:

IllegalArgumentException - if value < 0