Package org.joda.beans

Class JodaBeanUtils

java.lang.Object

org.joda.beans.JodaBeanUtils

public final class JodaBeanUtils
extends Object

A set of utilities to assist when working with beans and properties.

Method Summary

Modifier and Type	Method	Description
static Iterator<Bean>	beanIterator(Bean bean)	Returns an iterator over all the beans contained within the bean.
static <P> Function<Bean,P>	chain(Function<Bean,? extends Bean> fn1, MetaProperty<P> mp2)	Chains a function to a meta-property.
static <P> Function<Bean,P>	chain(MetaProperty<? extends Bean> mp1, MetaProperty<P> mp2)	Chains two meta-properties together.
static <T extends Bean> T	clone(T original)	Clones a bean.
static <T extends Bean> T	cloneAlways(T original)	Clones a bean always.
static Class<?>	collectionType(MetaProperty<?> prop, Class<?> targetClass)	Extracts the collection content type as a Class from a meta-property.
static Class<?>	collectionType(Property<?> prop)	Extracts the collection content type as a Class from a property.
static List<Class<?>>	collectionTypeTypes(MetaProperty<?> prop, Class<?> targetClass)	Extracts the map value type generic type parameters as a Class from a meta-property.
static Comparator<Bean>	comparator(Function<Bean,?> query, boolean ascending)	Obtains a comparator for the specified bean query.
static Comparator<Bean>	comparatorAscending(Function<Bean,?> query)	Obtains an ascending comparator for the specified bean query.
static Comparator<Bean>	comparatorDescending(Function<Bean,?> query)	Obtains an descending comparator for the specified bean query.
static <T extends Bean> BeanBuilder<T>	copy(Bean sourceBean, Class<T> destType)	Copies properties from a bean to a different bean type.
static <T extends Bean> BeanBuilder<T>	copyInto(Bean sourceBean, MetaBean destMeta, BeanBuilder<T> destBuilder)	Copies properties from a bean to a builder, which may be for a different type.
static boolean	equal(double val1, double val2)	Checks if two doubles are equal based on identity.
static boolean	equal(float val1, float val2)	Checks if two floats are equal based on identity.
static boolean	equal(Object obj1, Object obj2)	Checks if two objects are equal handling null.
static boolean	equalIgnoring(Bean bean1, Bean bean2, MetaProperty<?>... properties)	Checks if two beans are equal ignoring one or more properties.
static boolean	equalWithTolerance(double val1, double val2, double tolerance)	Checks if two doubles are equal within the specified tolerance.
static boolean	equalWithTolerance(float val1, float val2, double tolerance)	Checks if two floats are equal within the specified tolerance.
static Class<?>	extractTypeClass(MetaProperty<?> prop, Class<?> targetClass, int size, int index)	Low-level method to extract generic type information.
static Map<String,Object>	flatten(Bean bean)	Flattens a bean to a Map.
static int	hashCode(boolean value)	Returns a hash code for a boolean.
static int	hashCode(double value)	Returns a hash code for a double.
static int	hashCode(float value)	Returns a hash code for a float.
static int	hashCode(int value)	Returns a hash code for an int.
static int	hashCode(long value)	Returns a hash code for a long.
static int	hashCode(Object obj)	Returns a hash code for an object handling null.
static Class<?>	mapKeyType(MetaProperty<?> prop, Class<?> targetClass)	Extracts the map key type as a Class from a meta-property.
static Class<?>	mapKeyType(Property<?> prop)	Extracts the map key type as a Class from a meta-property.
static Class<?>	mapValueType(MetaProperty<?> prop, Class<?> targetClass)	Extracts the map value type as a Class from a meta-property.
static Class<?>	mapValueType(Property<?> prop)	Extracts the map value type as a Class from a meta-property.
static List<Class<?>>	mapValueTypeTypes(MetaProperty<?> prop, Class<?> targetClass)	Extracts the map value type generic type parameters as a Class from a meta-property.
static MetaBean	metaBean(Class<?> cls)	Deprecated. Use MetaBean.of(Class)
static void	notBlank(String value, String propertyName)	Checks if the value is not blank, throwing an exception if it is.
static void	notEmpty(String value, String propertyName)	Checks if the value is not empty, throwing an exception if it is.
static void	notEmpty(Collection<?> value, String propertyName)	Checks if the collection value is not empty, throwing an exception if it is.
static void	notEmpty(Map<?,?> value, String propertyName)	Checks if the map value is not empty, throwing an exception if it is.
static void	notNull(Object value, String propertyName)	Checks if the value is not null, throwing an exception if it is.
static boolean	propertiesEqual(Bean bean1, Bean bean2)	Checks if the two beans have the same set of properties.
static int	propertiesHashCode(Bean bean)	Returns a hash code based on the set of properties on a bean.
static String	propertiesToString(Bean bean, String prefix)	Returns a string describing the set of properties on a bean.
static void	registerMetaBean(MetaBean metaBean)	Deprecated. Use MetaBean.register(MetaBean)
static org.joda.convert.StringConvert	stringConverter()	Gets the standard string format converter.
static String	toString(Object obj)	Returns the toString value handling arrays.

Methods inherited from class java.lang.Object

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

Method Detail

metaBean

@Deprecated
public static MetaBean metaBean(Class<?> cls)

Deprecated.

Use MetaBean.of(Class)

Obtains a meta-bean from a Class.

This will return a meta-bean if it has been registered, or if the class implements DynamicBean and has a no-args constructor. Note that the common case where the meta-bean is registered by a static initializer is handled.

Parameters:

cls - the class to get the meta-bean for, not null

Returns:

the meta-bean, not null

Throws:

IllegalArgumentException - if unable to obtain the meta-bean

registerMetaBean

@Deprecated
public static void registerMetaBean(MetaBean metaBean)

Deprecated.

Use MetaBean.register(MetaBean)

Registers a meta-bean.

This should be done for all beans in a static factory where possible. If the meta-bean is dynamic, this method should not be called.

Parameters:

metaBean - the meta-bean, not null

Throws:

IllegalArgumentException - if unable to register

stringConverter

public static org.joda.convert.StringConvert stringConverter()

Gets the standard string format converter.

This returns a singleton that may be mutated (holds a concurrent map). New conversions should be registered at program startup.

Returns:

the standard string converter, not null

equal

public static boolean equal(Object obj1,
                            Object obj2)

Checks if two objects are equal handling null.

Parameters:

obj1 - the first object, may be null

obj2 - the second object, may be null

Returns:

true if equal

equal

public static boolean equal(float val1,
                            float val2)

Checks if two floats are equal based on identity.

This performs the same check as Float.equals(Object).

Parameters:

val1 - the first value, may be null

val2 - the second value, may be null

Returns:

true if equal

equalWithTolerance

public static boolean equalWithTolerance(float val1,
                                         float val2,
                                         double tolerance)

Checks if two floats are equal within the specified tolerance.

Two NaN values are equal. Positive and negative infinity are only equal with themselves. Otherwise, the difference between the values is compared to the tolerance.

Parameters:

val1 - the first value, may be null

val2 - the second value, may be null

tolerance - the tolerance used to compare equal

Returns:

true if equal

equal

public static boolean equal(double val1,
                            double val2)

Checks if two doubles are equal based on identity.

This performs the same check as Double.equals(Object).

Parameters:

val1 - the first value, may be null

val2 - the second value, may be null

Returns:

true if equal

equalWithTolerance

public static boolean equalWithTolerance(double val1,
                                         double val2,
                                         double tolerance)

Checks if two doubles are equal within the specified tolerance.

Two NaN values are equal. Positive and negative infinity are only equal with themselves. Otherwise, the difference between the values is compared to the tolerance. The tolerance is expected to be a finite value, not NaN or infinity.

Parameters:

val1 - the first value, may be null

val2 - the second value, may be null

tolerance - the tolerance used to compare equal

Returns:

true if equal

hashCode

public static int hashCode(Object obj)

Returns a hash code for an object handling null.

Parameters:

obj - the object, may be null

Returns:

the hash code

hashCode

public static int hashCode(boolean value)

Returns a hash code for a boolean.

Parameters:

value - the value to convert to a hash code

Returns:

the hash code

hashCode

public static int hashCode(int value)

Returns a hash code for an int.

Parameters:

value - the value to convert to a hash code

Returns:

the hash code

hashCode

public static int hashCode(long value)

Returns a hash code for a long.

Parameters:

value - the value to convert to a hash code

Returns:

the hash code

hashCode

public static int hashCode(float value)

Returns a hash code for a float.

Parameters:

value - the value to convert to a hash code

Returns:

the hash code

hashCode

public static int hashCode(double value)

Returns a hash code for a double.

Parameters:

value - the value to convert to a hash code

Returns:

the hash code

toString

public static String toString(Object obj)

Returns the toString value handling arrays.

Parameters:

obj - the object, may be null

Returns:

the string, not null

propertiesEqual

public static boolean propertiesEqual(Bean bean1,
                                      Bean bean2)

Checks if the two beans have the same set of properties.

This comparison checks that both beans have the same set of property names and that the value of each property name is also equal. It does not check the bean type, thus a FlexiBean may be equal to a DirectBean.

This comparison is usable with the propertiesHashCode(org.joda.beans.Bean) method. The result is the same as that if each bean was converted to a Map from name to value.

Parameters:

bean1 - the first bean to compare, not null

bean2 - the second bean to compare, not null

Returns:

true if equal

propertiesHashCode

public static int propertiesHashCode(Bean bean)

Returns a hash code based on the set of properties on a bean.

This hash code is usable with the propertiesEqual(org.joda.beans.Bean, org.joda.beans.Bean) method. The result is the same as that if each bean was converted to a Map from name to value.

Parameters:

bean - the bean to generate a hash code for, not null

Returns:

the hash code

propertiesToString

public static String propertiesToString(Bean bean,
                                        String prefix)

Returns a string describing the set of properties on a bean.

The result is the same as that if the bean was converted to a Map from name to value.

Parameters:

bean - the bean to generate a string for, not null

prefix - the prefix to use, null ignored

Returns:

the string form of the bean, not null

flatten

public static Map<String,Object> flatten(Bean bean)

Flattens a bean to a Map.

The returned map will contain all the properties from the bean with their actual values.

Parameters:

bean - the bean to generate a string for, not null

Returns:

the bean as a map, not null

copy

public static <T extends Bean> BeanBuilder<T> copy(Bean sourceBean,
                                                   Class<T> destType)

Copies properties from a bean to a different bean type.

This copies each non-null property value from the source bean to the destination builder provided that the destination builder supports the property name and the type is compatible.

Type Parameters:

T - the type of the bean to create

Parameters:

sourceBean - the bean to copy from, not null

destType - the type of the destination bean, not null

Returns:

the copied bean as a builder

Throws:

RuntimeException - if unable to copy a property

copyInto

public static <T extends Bean> BeanBuilder<T> copyInto(Bean sourceBean,
                                                       MetaBean destMeta,
                                                       BeanBuilder<T> destBuilder)

Copies properties from a bean to a builder, which may be for a different type.

This copies each non-null property value from the source bean to the destination builder provided that the destination builder supports the property name and the type is compatible.

Type Parameters:

T - the type of the bean to create

Parameters:

sourceBean - the bean to copy from, not null

destMeta - the meta bean of the destination, not null

destBuilder - the builder to populate, not null

Returns:

the updated builder

Throws:

RuntimeException - if unable to copy a property

clone

public static <T extends Bean> T clone(T original)

Clones a bean.

This performs a deep clone. There is no protection against cycles in the object graph beyond StackOverflowError.

Type Parameters:

T - the type of the bean

Parameters:

original - the original bean to clone, null returns null

Returns:

the cloned bean, null if null input

cloneAlways

public static <T extends Bean> T cloneAlways(T original)

Clones a bean always.

This performs a deep clone. There is no protection against cycles in the object graph beyond StackOverflowError. This differs from Object.clone() in that immutable beans are also cloned.

Type Parameters:

T - the type of the bean

Parameters:

original - the original bean to clone, not null

Returns:

the cloned bean, not null

notNull

public static void notNull(Object value,
                           String propertyName)

Checks if the value is not null, throwing an exception if it is.

Parameters:

value - the value to check, may be null

propertyName - the property name, should not be null

Throws:

IllegalArgumentException - if the value is null

notBlank

public static void notBlank(String value,
                            String propertyName)

Checks if the value is not blank, throwing an exception if it is.

Validate that the specified argument is not null and has at least one non-whitespace character.

Parameters:

value - the value to check, may be null

propertyName - the property name, should not be null

Throws:

IllegalArgumentException - if the value is null or empty

notEmpty

public static void notEmpty(String value,
                            String propertyName)

Checks if the value is not empty, throwing an exception if it is.

Parameters:

value - the value to check, may be null

propertyName - the property name, should not be null

Throws:

IllegalArgumentException - if the value is null or empty

notEmpty

public static void notEmpty(Collection<?> value,
                            String propertyName)

Checks if the collection value is not empty, throwing an exception if it is.

Parameters:

value - the value to check, may be null

propertyName - the property name, should not be null

Throws:

IllegalArgumentException - if the value is null or empty

notEmpty

public static void notEmpty(Map<?,?> value,
                            String propertyName)

Checks if the map value is not empty, throwing an exception if it is.

Parameters:

value - the value to check, may be null

propertyName - the property name, should not be null

Throws:

IllegalArgumentException - if the value is null or empty

collectionType

public static Class<?> collectionType(Property<?> prop)

Extracts the collection content type as a Class from a property.

This method allows the resolution of generics in certain cases.

Parameters:

prop - the property to examine, not null

Returns:

the collection content type, null if unable to determine or type has no generic parameters

collectionType

public static Class<?> collectionType(MetaProperty<?> prop,
                                      Class<?> targetClass)

Extracts the collection content type as a Class from a meta-property.

The target type is the type of the object, not the declaring type of the meta-property.

Parameters:

prop - the property to examine, not null

targetClass - the target type to evaluate against, not null

Returns:

the collection content type, null if unable to determine or type has no generic parameters

collectionTypeTypes

public static List<Class<?>> collectionTypeTypes(MetaProperty<?> prop,
                                                 Class<?> targetClass)

Extracts the map value type generic type parameters as a Class from a meta-property.

The target type is the type of the object, not the declaring type of the meta-property.

This is used when the collection generic parameter is a map or collection.

Parameters:

prop - the property to examine, not null

targetClass - the target type to evaluate against, not null

Returns:

the collection content type generic parameters, empty if unable to determine, no nulls

mapKeyType

public static Class<?> mapKeyType(Property<?> prop)

Extracts the map key type as a Class from a meta-property.

Parameters:

prop - the property to examine, not null

Returns:

the map key type, null if unable to determine or type has no generic parameters

mapKeyType

public static Class<?> mapKeyType(MetaProperty<?> prop,
                                  Class<?> targetClass)

Extracts the map key type as a Class from a meta-property.

The target type is the type of the object, not the declaring type of the meta-property.

Parameters:

prop - the property to examine, not null

targetClass - the target type to evaluate against, not null

Returns:

the map key type, null if unable to determine or type has no generic parameters

mapValueType

public static Class<?> mapValueType(Property<?> prop)

Extracts the map value type as a Class from a meta-property.

Parameters:

prop - the property to examine, not null

Returns:

the map value type, null if unable to determine or type has no generic parameters

mapValueType

public static Class<?> mapValueType(MetaProperty<?> prop,
                                    Class<?> targetClass)

Extracts the map value type as a Class from a meta-property.

The target type is the type of the object, not the declaring type of the meta-property.

Parameters:

prop - the property to examine, not null

targetClass - the target type to evaluate against, not null

Returns:

the map value type, null if unable to determine or type has no generic parameters

mapValueTypeTypes

public static List<Class<?>> mapValueTypeTypes(MetaProperty<?> prop,
                                               Class<?> targetClass)

Extracts the map value type generic type parameters as a Class from a meta-property.

The target type is the type of the object, not the declaring type of the meta-property.

This is used when the map value generic parameter is a map or collection.

Parameters:

prop - the property to examine, not null

targetClass - the target type to evaluate against, not null

Returns:

the map value type generic parameters, empty if unable to determine, no nulls

extractTypeClass

public static Class<?> extractTypeClass(MetaProperty<?> prop,
                                        Class<?> targetClass,
                                        int size,
                                        int index)

Low-level method to extract generic type information.

Parameters:

prop - the property to examine, not null

targetClass - the target type to evaluate against, not null

size - the number of generic parameters expected

index - the index of the generic parameter

Returns:

the type, null if unable to determine or type has no generic parameters

equalIgnoring

public static boolean equalIgnoring(Bean bean1,
                                    Bean bean2,
                                    MetaProperty<?>... properties)

Checks if two beans are equal ignoring one or more properties.

This version of equalIgnoring only checks properties at the top level. For example, if a Person bean contains an Address bean then only properties on the Person bean will be checked against the ignore list.

Parameters:

bean1 - the first bean, not null

bean2 - the second bean, not null

properties - the properties to ignore, not null

Returns:

true if equal

Throws:

IllegalArgumentException - if inputs are null

beanIterator

public static Iterator<Bean> beanIterator(Bean bean)

Returns an iterator over all the beans contained within the bean.

The iterator is a depth-first traversal of the beans within the specified bean. The first returned bean is the specified bean. Beans within collections will be returned.

A cycle in the bean structure will cause an infinite loop.

Parameters:

bean - the bean to iterate over, not null

Returns:

the iterator, not null

chain

public static <P> Function<Bean,P> chain(MetaProperty<? extends Bean> mp1,
                                               MetaProperty<P> mp2)

Chains two meta-properties together.

The resulting function takes an instance of a bean, queries using the first meta-property, then queries the result using the second meta-property. If the first returns null, the result will be null.

Type Parameters:

P - the type of the result of the chain

Parameters:

mp1 - the first meta-property, not null

mp2 - the second meta-property, not null

Returns:

the chain function, not null

chain

public static <P> Function<Bean,P> chain(Function<Bean,? extends Bean> fn1,
                                               MetaProperty<P> mp2)

Chains a function to a meta-property.

The resulting function takes an instance of a bean, queries using the first function, then queries the result using the second meta-property. If the first returns null, the result will be null.

Type Parameters:

P - the type of the result of the chain

Parameters:

fn1 - the first meta-property, not null

mp2 - the second meta-property, not null

Returns:

the chain function, not null

comparator

public static Comparator<Bean> comparator(Function<Bean,?> query,
                                          boolean ascending)

Obtains a comparator for the specified bean query.

The result of the query must be Comparable.

To use this with a meta-property append ::get to the meta-property, for example Address.meta().street()::get.

Parameters:

query - the query to use, not null

ascending - true for ascending, false for descending

Returns:

the comparator, not null

comparatorAscending

public static Comparator<Bean> comparatorAscending(Function<Bean,?> query)

Obtains an ascending comparator for the specified bean query.

The result of the query must be Comparable.

Parameters:

query - the query to use, not null

Returns:

the comparator, not null

comparatorDescending

public static Comparator<Bean> comparatorDescending(Function<Bean,?> query)

Obtains an descending comparator for the specified bean query.

The result of the query must be Comparable.

Parameters:

query - the query to use, not null

Returns:

the comparator, not null