bboss.org.apache.velocity.app.event

接口 InvalidReferenceEventHandler

所有超级接口:

EventHandler

所有已知实现类:

ReportInvalidReferences

public interface InvalidReferenceEventHandler
extends EventHandler

Event handler called when an invalid reference is encountered. Allows the application to report errors or substitute return values. May be chained in sequence; the behavior will differ per method.

This feature should be regarded as experimental.

从以下版本开始:

1.5

嵌套类概要

嵌套类

限定符和类型	接口和说明
static class	InvalidReferenceEventHandler.InvalidGetMethodExecutor Defines the execution strategy for invalidGetMethod
static class	InvalidReferenceEventHandler.InvalidMethodExecutor Defines the execution strategy for invalidGetMethod
static class	InvalidReferenceEventHandler.InvalidSetMethodExecutor Defines the execution strategy for invalidGetMethod

方法概要

限定符和类型	方法和说明
java.lang.Object	invalidGetMethod(Context context, java.lang.String reference, java.lang.Object object, java.lang.String property, Info info) Called when object is null or there is no getter for the given property.
java.lang.Object	invalidMethod(Context context, java.lang.String reference, java.lang.Object object, java.lang.String method, Info info) Called when object is null or the given method does not exist.
boolean	invalidSetMethod(Context context, java.lang.String leftreference, java.lang.String rightreference, Info info) Called when object is null or there is no setter for the given property.

方法详细资料

invalidGetMethod

java.lang.Object invalidGetMethod(Context context,
                                  java.lang.String reference,
                                  java.lang.Object object,
                                  java.lang.String property,
                                  Info info)

Called when object is null or there is no getter for the given property. Also called for invalid references without properties. invalidGetMethod() will be called in sequence for each link in the chain until the first non-null value is returned.

参数:

context - the context when the reference was found invalid

reference - string with complete invalid reference. If silent reference, will start with $!

object - the object referred to, or null if not found

property - the property name from the reference

info - contains template, line, column details

返回:

substitute return value for missing reference, or null if no substitute

invalidSetMethod

boolean invalidSetMethod(Context context,
                         java.lang.String leftreference,
                         java.lang.String rightreference,
                         Info info)

Called when object is null or there is no setter for the given property. invalidSetMethod() will be called in sequence for each link in the chain until a true value is returned. It's recommended that false be returned as a default to allow for easy chaining.

参数:

context - the context when the reference was found invalid

leftreference - left reference being assigned to

rightreference - invalid reference on the right

info - contains info on template, line, col

返回:

if true then stop calling invalidSetMethod along the chain.

invalidMethod

java.lang.Object invalidMethod(Context context,
                               java.lang.String reference,
                               java.lang.Object object,
                               java.lang.String method,
                               Info info)

Called when object is null or the given method does not exist. invalidMethod() will be called in sequence for each link in the chain until the first non-null value is returned.

参数:

context - the context when the reference was found invalid

reference - string with complete invalid reference. If silent reference, will start with $!

object - the object referred to, or null if not found

method - the name of the (non-existent) method

info - contains template, line, column details

返回:

substitute return value for missing reference, or null if no substitute