Package io.cui.tools.property

Class PropertyHolder

java.lang.Object

io.cui.tools.property.PropertyHolder

public final class PropertyHolder
extends Object

Overview

An instance of PropertyHolder provides runtime information for a specific BeanProperty. Under the hood it uses Beans tooling provided by the JDK and the utilities PropertyUtil an and MoreReflection. Compared to the standard tooling it is more flexible regarding fluent api style of bean / DTOs.

Usage

The usual entry-point is from(Class, String). In case you want to create your own instance you can use the contained builder directly using builder()

Now you can access the metadata for that property, see getMemberInfo(), getName(), getType(), getReadMethod()

Reading and writing of properties should be done by readFrom(Object) and writeTo(Object, Object). Directly using getReadMethod() and getWriteMethod() is more error-prone and less versatile.

Caution:

Use reflection only if there is no other way. Even if some of the problems are minimized by using this type. It should be used either in test-code, what we actually do, and not production code. An other reason could be framework code. as for that you should exactly know what you do.

Author:

Oliver Wolff

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PropertyHolder.PropertyHolderBuilder

Method Summary

Modifier and Type	Method	Description
static PropertyHolder.PropertyHolderBuilder	builder()
boolean	equals(Object o)
static Optional<PropertyHolder>	from(Class<?> beanType, String attributeName)	Factory Method for creating a concrete PropertyHolder
@NonNull PropertyMemberInfo	getMemberInfo()	Provides additional runtime information for the property, see PropertyMemberInfo
@NonNull String	getName()	The name of the property.
Method	getReadMethod()	Derived by PropertyDescriptor, may be null
@NonNull PropertyReadWrite	getReadWrite()	Provides additional Runtime-information, see PropertyReadWrite
@NonNull Class<?>	getType()	The actual type of the property.
Method	getWriteMethod()	Derived by PropertyDescriptor, may be null
int	hashCode()
Object	readFrom(Object bean)	Reads the property on the given bean identified by the concrete PropertyHolder and the given bean.
String	toString()
Object	writeTo(Object bean, Object propertyValue)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

readFrom

public Object readFrom(Object bean)

Reads the property on the given bean identified by the concrete PropertyHolder and the given bean. First it tries to access the readMethod derived by the PropertyDescriptor. If this can not be achieved, e.g. for types that do not match exactly Java-Bean-Specification it tries to read the property by using PropertyUtil.readProperty(Object, String)

Parameters:

bean - instance to be read from, must not be null

Returns:

the object read from the property

Throws:

IllegalStateException - in case the property can not be read, see PropertyReadWrite.isReadable()

IllegalStateException - in case some Exception occurred while reading

writeTo

public Object writeTo(Object bean,
                      Object propertyValue)

Parameters:

bean - instance to be read from, must not be null

propertyValue - to be set

Returns:

In case the property set method is void the given bean will be returned. Otherwise, the return value of the method invocation, assuming the setMethods is a builder / fluent-api type.

Throws:

IllegalStateException - in case the property can not be read, see PropertyReadWrite.isWriteable()

IllegalStateException - in case some Exception occurred while writing

from

public static Optional<PropertyHolder> from(Class<?> beanType,
                                            String attributeName)

Factory Method for creating a concrete PropertyHolder

Parameters:

beanType - must not be null

attributeName - must not be null nor empty

Returns:

the concrete PropertyHolder for the given parameter if applicable

Throws:

IllegalArgumentException - for cases where Introspector is not capable of resolving a PropertyDescriptor. This is usually the case if it is not a valid bean.

builder

public static PropertyHolder.PropertyHolderBuilder builder()

getName

@NonNull
public @NonNull String getName()

The name of the property.

getType

@NonNull
public @NonNull Class<?> getType()

The actual type of the property.

getMemberInfo

@NonNull
public @NonNull PropertyMemberInfo getMemberInfo()

Provides additional runtime information for the property, see PropertyMemberInfo

getReadWrite

@NonNull
public @NonNull PropertyReadWrite getReadWrite()

Provides additional Runtime-information, see PropertyReadWrite

getReadMethod

public Method getReadMethod()

Derived by PropertyDescriptor, may be null

getWriteMethod

public Method getWriteMethod()

Derived by PropertyDescriptor, may be null

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object