程序包 cn.taketoday.expression.spel.support

类 ReflectivePropertyAccessor

java.lang.Object

cn.taketoday.expression.spel.support.ReflectivePropertyAccessor

所有已实现的接口:

PropertyAccessor

直接已知子类:

DataBindingPropertyAccessor

public class ReflectivePropertyAccessor
extends Object
implements PropertyAccessor

A powerful PropertyAccessor that uses reflection to access properties for reading and possibly also for writing on a target instance.

A property can be referenced through a public getter method (when being read) or a public setter method (when being written), and also as a public field.

从以下版本开始:

4.0

作者:

Andy Clement, Juergen Hoeller, Phillip Webb, Sam Brannen, Harry Yang

另请参阅:

• StandardEvaluationContext
• SimpleEvaluationContext
• DataBindingPropertyAccessor

嵌套类概要

嵌套类

修饰符和类型	类	说明
private static class	ReflectivePropertyAccessor.InvokerPair	Captures the member (method/field) to call reflectively to access a property value and the type descriptor for the value returned by the reflective call.
static class	ReflectivePropertyAccessor.OptimalPropertyAccessor	An optimized form of a PropertyAccessor that will use reflection but only knows how to access a particular property on a particular class.
private static final class	ReflectivePropertyAccessor.PropertyCacheKey

字段概要

字段

修饰符和类型	字段	说明
private final boolean	allowWrite
private static final Set<Class<?>>	ANY_TYPES
private static final Set<Class<?>>	BOOLEAN_TYPES
private final Map<ReflectivePropertyAccessor.PropertyCacheKey,ReflectivePropertyAccessor.InvokerPair>	readerCache
private final Map<Class<?>,Method[]>	sortedMethodsCache
private final Map<ReflectivePropertyAccessor.PropertyCacheKey,TypeDescriptor>	typeDescriptorCache
private final Map<ReflectivePropertyAccessor.PropertyCacheKey,Member>	writerCache

构造器概要

构造器

构造器	说明
ReflectivePropertyAccessor()	Create a new property accessor for reading as well writing.
ReflectivePropertyAccessor(boolean allowWrite)	Create a new property accessor for reading and possibly also writing.

方法概要

修饰符和类型	方法	说明
boolean	canRead(EvaluationContext context, Object target, String name)	Called to determine if a resolver instance is able to access a specified property on a specified target object.
boolean	canWrite(EvaluationContext context, Object target, String name)	Called to determine if a resolver instance is able to write to a specified property on a specified target object.
PropertyAccessor	createOptimalAccessor(EvaluationContext context, Object target, String name)	Attempt to create an optimized property accessor tailored for a property of a particular name on a particular class.
protected Field	findField(String name, Class<?> clazz, boolean mustBeStatic)	Find a field of a certain name on a specified class.
private Field	findField(String name, Class<?> clazz, Object target)
protected Method	findGetterForProperty(String propertyName, Class<?> clazz, boolean mustBeStatic)	Find a getter method for the specified property.
private Method	findGetterForProperty(String propertyName, Class<?> clazz, Object target)
private Method	findMethodForProperty(String[] methodSuffixes, String prefix, Class<?> clazz, boolean mustBeStatic, int numberOfParams, Set<Class<?>> requiredReturnTypes)
protected Method	findSetterForProperty(String propertyName, Class<?> clazz, boolean mustBeStatic)	Find a setter method for the specified property.
private Method	findSetterForProperty(String propertyName, Class<?> clazz, Object target)
protected String	getPropertyMethodSuffix(String propertyName)	Return the method suffix for a given property name.
protected String[]	getPropertyMethodSuffixes(String propertyName)	Return the method suffixes for a given property name.
private Method[]	getSortedMethods(Class<?> clazz)	Return class methods ordered with non-bridge methods appearing higher.
Class<?>[]	getSpecificTargetClasses()	Returns null which means this is a general purpose accessor.
private TypeDescriptor	getTypeDescriptor(EvaluationContext context, Object target, String name)
private TypeDescriptor	getTypeDescriptor(Method readMethod, Method writeMethod, Class<?> declaringClass)
protected boolean	isCandidateForProperty(Method method, Class<?> targetClass)	Determine whether the given Method is a candidate for property access on an instance of the given target class.
TypedValue	read(EvaluationContext context, Object target, String name)	Called to read a property from a specified target object.
void	write(EvaluationContext context, Object target, String name, Object newValue)	Called to write to a property on a specified target object.

从类继承的方法 java.lang.Object

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

字段详细资料

ANY_TYPES

private static final Set<Class<?>> ANY_TYPES

BOOLEAN_TYPES

private static final Set<Class<?>> BOOLEAN_TYPES

allowWrite

private final boolean allowWrite

readerCache

private final Map<ReflectivePropertyAccessor.PropertyCacheKey,ReflectivePropertyAccessor.InvokerPair> readerCache

writerCache

private final Map<ReflectivePropertyAccessor.PropertyCacheKey,Member> writerCache

typeDescriptorCache

private final Map<ReflectivePropertyAccessor.PropertyCacheKey,TypeDescriptor> typeDescriptorCache

sortedMethodsCache

private final Map<Class<?>,Method[]> sortedMethodsCache

构造器详细资料

ReflectivePropertyAccessor

public ReflectivePropertyAccessor()

Create a new property accessor for reading as well writing.

另请参阅:

• ReflectivePropertyAccessor(boolean)

ReflectivePropertyAccessor

public ReflectivePropertyAccessor(boolean allowWrite)

Create a new property accessor for reading and possibly also writing.

参数:

allowWrite - whether to allow write operations on a target instance

另请参阅:

• canWrite(cn.taketoday.expression.EvaluationContext, java.lang.Object, java.lang.String)

方法详细资料

getSpecificTargetClasses

@Nullable
public Class<?>[] getSpecificTargetClasses()

Returns null which means this is a general purpose accessor.

指定者:

getSpecificTargetClasses 在接口中 PropertyAccessor

返回:

an array of classes that this resolver is suitable for (or null if a general resolver)

canRead

public boolean canRead(EvaluationContext context,
 @Nullable
 Object target,
 String name)
                throws AccessException

从接口复制的说明: PropertyAccessor

Called to determine if a resolver instance is able to access a specified property on a specified target object.

指定者:

canRead 在接口中 PropertyAccessor

参数:

context - the evaluation context in which the access is being attempted

target - the target object upon which the property is being accessed

name - the name of the property being accessed

返回:

true if this resolver is able to read the property

抛出:

AccessException - if there is any problem determining whether the property can be read

read

public TypedValue read(EvaluationContext context,
 @Nullable
 Object target,
 String name)
                throws AccessException

从接口复制的说明: PropertyAccessor

Called to read a property from a specified target object. Should only succeed if PropertyAccessor.canRead(cn.taketoday.expression.EvaluationContext, java.lang.Object, java.lang.String) also returns true.

指定者:

read 在接口中 PropertyAccessor

参数:

context - the evaluation context in which the access is being attempted

target - the target object upon which the property is being accessed

name - the name of the property being accessed

返回:

a TypedValue object wrapping the property value read and a type descriptor for it

抛出:

AccessException - if there is any problem accessing the property value

canWrite

public boolean canWrite(EvaluationContext context,
 @Nullable
 Object target,
 String name)
                 throws AccessException

从接口复制的说明: PropertyAccessor

Called to determine if a resolver instance is able to write to a specified property on a specified target object.

指定者:

canWrite 在接口中 PropertyAccessor

参数:

context - the evaluation context in which the access is being attempted

target - the target object upon which the property is being accessed

name - the name of the property being accessed

返回:

true if this resolver is able to write to the property

抛出:

AccessException - if there is any problem determining whether the property can be written to

getTypeDescriptor

private TypeDescriptor getTypeDescriptor(@Nullable
 Method readMethod,
 @Nullable
 Method writeMethod,
 @Nullable
 Class<?> declaringClass)

write

public void write(EvaluationContext context,
 @Nullable
 Object target,
 String name,
 @Nullable
 Object newValue)
           throws AccessException

从接口复制的说明: PropertyAccessor

Called to write to a property on a specified target object. Should only succeed if PropertyAccessor.canWrite(cn.taketoday.expression.EvaluationContext, java.lang.Object, java.lang.String) also returns true.

指定者:

write 在接口中 PropertyAccessor

参数:

context - the evaluation context in which the access is being attempted

target - the target object upon which the property is being accessed

name - the name of the property being accessed

newValue - the new value for the property

抛出:

AccessException - if there is any problem writing to the property value

getTypeDescriptor

@Nullable
private TypeDescriptor getTypeDescriptor(EvaluationContext context,
 Object target,
 String name)

findGetterForProperty

@Nullable
private Method findGetterForProperty(String propertyName,
 Class<?> clazz,
 Object target)

findSetterForProperty

@Nullable
private Method findSetterForProperty(String propertyName,
 Class<?> clazz,
 Object target)

findGetterForProperty

@Nullable
protected Method findGetterForProperty(String propertyName,
 Class<?> clazz,
 boolean mustBeStatic)

Find a getter method for the specified property.

findSetterForProperty

@Nullable
protected Method findSetterForProperty(String propertyName,
 Class<?> clazz,
 boolean mustBeStatic)

Find a setter method for the specified property.

findMethodForProperty

@Nullable
private Method findMethodForProperty(String[] methodSuffixes,
 String prefix,
 Class<?> clazz,
 boolean mustBeStatic,
 int numberOfParams,
 Set<Class<?>> requiredReturnTypes)

getSortedMethods

private Method[] getSortedMethods(Class<?> clazz)

Return class methods ordered with non-bridge methods appearing higher.

isCandidateForProperty

protected boolean isCandidateForProperty(Method method,
 Class<?> targetClass)

Determine whether the given Method is a candidate for property access on an instance of the given target class.

The default implementation considers any method as a candidate, even for non-user-declared properties on the Object base class.

参数:

method - the Method to evaluate

targetClass - the concrete target class that is being introspected

从以下版本开始:

4.0

getPropertyMethodSuffixes

protected String[] getPropertyMethodSuffixes(String propertyName)

Return the method suffixes for a given property name. The default implementation uses JavaBean conventions with additional support for properties of the form 'xY' where the method 'getXY()' is used in preference to the JavaBean convention of 'getxY()'.

getPropertyMethodSuffix

protected String getPropertyMethodSuffix(String propertyName)

Return the method suffix for a given property name. The default implementation uses JavaBean conventions.

findField

@Nullable
private Field findField(String name,
 Class<?> clazz,
 Object target)

findField

@Nullable
protected Field findField(String name,
 Class<?> clazz,
 boolean mustBeStatic)

Find a field of a certain name on a specified class.

createOptimalAccessor

public PropertyAccessor createOptimalAccessor(EvaluationContext context,
 @Nullable
 Object target,
 String name)

Attempt to create an optimized property accessor tailored for a property of a particular name on a particular class. The general ReflectivePropertyAccessor will always work but is not optimal due to the need to lookup which reflective member (method/field) to use each time read() is called. This method will just return the ReflectivePropertyAccessor instance if it is unable to build a more optimal accessor.

Note: An optimal accessor is currently only usable for read attempts. Do not call this method if you need a read-write accessor.

另请参阅:

• ReflectivePropertyAccessor.OptimalPropertyAccessor