|
||||||||||
上一个类 下一个类 | 框架 无框架 | |||||||||
摘要: 嵌套 | 字段 | 构造方法 | 方法 | 详细信息: 字段 | 构造方法 | 方法 |
java.lang.Objectorg.activiti.engine.impl.javax.el.ELResolver
org.activiti.engine.impl.javax.el.BeanELResolver
public class BeanELResolver
Defines property resolution behavior on objects using the JavaBeans component architecture. This
resolver handles base objects of any type, as long as the base is not null. It accepts any object
as a property, and coerces it to a string. That string is then used to find a JavaBeans compliant
property on the base object. The value is accessed using JavaBeans getters and setters. This
resolver can be constructed in read-only mode, which means that isReadOnly will always return
true and setValue(ELContext, Object, Object, Object)
will always throw
PropertyNotWritableException. ELResolvers are combined together using CompositeELResolver
s, to define rich semantics for evaluating an expression. See the javadocs for ELResolver
for details. Because this resolver handles base objects of any type, it should be placed near the
end of a composite resolver. Otherwise, it will claim to have resolved a property before any
resolvers that come after it get a chance to test if they can do so as well.
CompositeELResolver
,
ELResolver
嵌套类摘要 | |
---|---|
protected static class |
BeanELResolver.BeanProperties
|
protected static class |
BeanELResolver.BeanProperty
|
字段摘要 |
---|
从类 org.activiti.engine.impl.javax.el.ELResolver 继承的字段 |
---|
RESOLVABLE_AT_DESIGN_TIME, TYPE |
构造方法摘要 | |
---|---|
BeanELResolver()
Creates a new read/write BeanELResolver. |
|
BeanELResolver(boolean readOnly)
Creates a new BeanELResolver whose read-only status is determined by the given parameter. |
方法摘要 | |
---|---|
Class<?> |
getCommonPropertyType(ELContext context,
Object base)
If the base object is not null, returns the most general type that this resolver accepts for the property argument. |
Iterator<FeatureDescriptor> |
getFeatureDescriptors(ELContext context,
Object base)
If the base object is not null, returns an Iterator containing the set of JavaBeans properties available on the given object. |
Class<?> |
getType(ELContext context,
Object base,
Object property)
If the base object is not null, returns the most general acceptable type that can be set on this bean property. |
Object |
getValue(ELContext context,
Object base,
Object property)
If the base object is not null, returns the current value of the given property on this bean. |
Object |
invoke(ELContext context,
Object base,
Object method,
Class<?>[] paramTypes,
Object[] params)
If the base object is not null , invoke the method, with the given parameters on
this bean. |
boolean |
isReadOnly(ELContext context,
Object base,
Object property)
If the base object is not null, returns whether a call to setValue(ELContext, Object, Object, Object) will always fail. |
void |
setValue(ELContext context,
Object base,
Object property,
Object value)
If the base object is not null, attempts to set the value of the given property on this bean. |
从类 java.lang.Object 继承的方法 |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
构造方法详细信息 |
---|
public BeanELResolver()
public BeanELResolver(boolean readOnly)
方法详细信息 |
---|
public Class<?> getCommonPropertyType(ELContext context, Object base)
ELResolver
中的 getCommonPropertyType
context
- The context of this evaluation.base
- The bean to analyze.
public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base)
ELResolver.TYPE
- The runtime type of the property, from
PropertyDescriptor.getPropertyType().ELResolver.RESOLVABLE_AT_DESIGN_TIME
- true.
ELResolver
中的 getFeatureDescriptors
context
- The context of this evaluation.base
- The bean to analyze.
public Class<?> getType(ELContext context, Object base, Object property)
ELResolver
中的 getType
context
- The context of this evaluation.base
- The bean to analyze.property
- The name of the property to analyze. Will be coerced to a String.
NullPointerException
- if context is null
PropertyNotFoundException
- if base is not null and the specified property does not exist or is not readable.
ELException
- if an exception was thrown while performing the property or variable resolution.
The thrown exception must be included as the cause property of this exception, if
available.public Object getValue(ELContext context, Object base, Object property)
ELResolver
中的 getValue
context
- The context of this evaluation.base
- The bean to analyze.property
- The name of the property to analyze. Will be coerced to a String.
NullPointerException
- if context is null
PropertyNotFoundException
- if base is not null and the specified property does not exist or is not readable.
ELException
- if an exception was thrown while performing the property or variable resolution.
The thrown exception must be included as the cause property of this exception, if
available.public boolean isReadOnly(ELContext context, Object base, Object property)
setValue(ELContext, Object, Object, Object)
will always fail. If the base is not
null, the propertyResolved property of the ELContext object must be set to true by this
resolver, before returning. If this property is not true after this method is called, the
caller can safely assume no value was set.
ELResolver
中的 isReadOnly
context
- The context of this evaluation.base
- The bean to analyze.property
- The name of the property to analyze. Will be coerced to a String.
NullPointerException
- if context is null
PropertyNotFoundException
- if base is not null and the specified property does not exist or is not readable.
ELException
- if an exception was thrown while performing the property or variable resolution.
The thrown exception must be included as the cause property of this exception, if
available.public void setValue(ELContext context, Object base, Object property, Object value)
ELResolver
中的 setValue
context
- The context of this evaluation.base
- The bean to analyze.property
- The name of the property to analyze. Will be coerced to a String.value
- The value to be associated with the specified key.
NullPointerException
- if context is null
PropertyNotFoundException
- if base is not null and the specified property does not exist or is not readable.
PropertyNotWritableException
- if this resolver was constructed in read-only mode, or if there is no setter for
the property
ELException
- if an exception was thrown while performing the property or variable resolution.
The thrown exception must be included as the cause property of this exception, if
available.public Object invoke(ELContext context, Object base, Object method, Class<?>[] paramTypes, Object[] params)
null
, invoke the method, with the given parameters on
this bean. The return value from the method is returned.
If the base is not null
, the propertyResolved
property of the
ELContext
object must be set to true
by this resolver, before
returning. If this property is not true
after this method is called, the caller
should ignore the return value.
The provided method object will first be coerced to a String
. The methods in the
bean is then examined and an attempt will be made to select one for invocation. If no
suitable can be found, a MethodNotFoundException
is thrown.
If the given paramTypes is not null
, select the method with the given name and
parameter types.
Else select the method with the given name that has the same number of parameters. If there
are more than one such method, the method selection process is undefined.
Else select the method with the given name that takes a variable number of arguments.
Note the resolution for overloaded methods will likely be clarified in a future version of
the spec.
The provided parameters are coerced to the corresponding parameter types of the method, and
the method is then invoked.
ELResolver
中的 invoke
context
- The context of this evaluation.base
- The bean on which to invoke the methodmethod
- The simple name of the method to invoke. Will be coerced to a String
.
If method is "<init>"or "<clinit>" a MethodNotFoundException is
thrown.paramTypes
- An array of Class objects identifying the method's formal parameter types, in
declared order. Use an empty array if the method has no parameters. Can be
null
, in which case the method's formal parameter types are assumed
to be unknown.params
- The parameters to pass to the method, or null
if no parameters.
null
if the method has a
void
return type).
MethodNotFoundException
- if no suitable method can be found.
ELException
- if an exception was thrown while performing (base, method) resolution. The thrown
exception must be included as the cause property of this exception, if available.
If the exception thrown is an InvocationTargetException
, extract its
cause
and pass it to the ELException
constructor.
|
||||||||||
上一个类 下一个类 | 框架 无框架 | |||||||||
摘要: 嵌套 | 字段 | 构造方法 | 方法 | 详细信息: 字段 | 构造方法 | 方法 |