Jakarta EE 11.0.0 · jakarta.el.OptionalELResolver · APIdia, the JavaDoc alternative

Access	Constructor and Description
public	OptionalELResolver()

Method Summary

Modifier and Type	Method and Description
public <T> T	Returns: If the base object is an `Optional` and `Optional#isEmpty()` returns `true` then this method returns the result of coercing `null` to the requested `type`. If the base object is an `Optional` and `Optional#isPresent()` returns `true` then this method returns the result of coercing `Optional#get()` to the requested `type`. If the base object is not an `Optional` then the return value is undefined. convertToType(ELContext The context of this evaluation. context, Object The object to convert. obj, Class<T> The target type for the conversion. type) Overrides jakarta.el.ELResolver.convertToType. Converts an object to a specific type.
public Class<?>	Returns: If the base object is an `Optional` this method always returns `Object.class`. If the base object is not an `Optional` then the return value is undefined. getCommonPropertyType(ELContext The context of this evaluation. context, Object The base object to return the most general property type for, or `null` to enumerate the set of top-level variables that this resolver can evaluate. base) Implements abstract jakarta.el.ELResolver.getCommonPropertyType. Returns the most general type that this resolver accepts for the `property` argument, given a `base` object.
public Class<?>	Returns: If the base object is an `Optional` this method always returns `null` since instances of this resolver are always read-only. If the base object is not an `Optional` then the return value is undefined. getType(ELContext The context of this evaluation. context, Object The base object whose property value is to be analyzed, or `null` to analyze a top-level variable. base, Object The property or variable to return the acceptable type for. property) Implements abstract jakarta.el.ELResolver.getType. For a given `base` and `property`, attempts to identify the most general type that is acceptable for an object to be passed as the `value` parameter in a future call to the `setValue` method.
public Object	Returns: If the base object is an `Optional` and `Optional#isEmpty()` returns `true` then the resulting value is `null`. If the base object is an `Optional`, `Optional#isPresent()` returns `true` and the property is `null` then the resulting value is the result of calling `Optional#get()` on the base object. If the base object is an `Optional`, `Optional#isPresent()` returns `true` and the property is not `null` then the resulting value is the result of calling `ELResolver#getValue(ELContext, Object, Object)` using the `ELResolver` obtained from `ELContext#getELResolver()` with the following parameters: The `ELContext` is the current context The base object is the result of calling `Optional#get()` on the current base object The property object is the current property object If the base object is not an `Optional` then the return value is undefined. getValue(ELContext The context of this evaluation. context, Object The base object whose property value is to be returned, or `null` to resolve a top-level variable. base, Object The property or variable to be resolved. property) Implements abstract jakarta.el.ELResolver.getValue. Attempts to resolve the given `property` object on the given `base` object.
public Object	Returns: If the base object is an `Optional` and `Optional#isEmpty()` returns `true` then this method returns `null`. If the base object is an `Optional` and `Optional#isPresent()` returns `true` then this method returns the result of invoking the specified method on the object obtained by calling `Optional#get()` with the specified parameters. If the base object is not an `Optional` then the return value is undefined. invoke(ELContext The context of this evaluation. context, Object The bean on which to invoke the method base, Object The simple name of the method to invoke. Will be coerced to a `String`. method, Class<?>[] 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. paramTypes, Object[] The parameters to pass to the method, or `null` if no parameters. params) Overrides jakarta.el.ELResolver.invoke. Attempts to resolve and invoke the given `method` on the given `base` object.
public boolean	Returns: If the base object is an `Optional` this method always returns `true` since instances of this resolver are always read-only. If the base object is not an `Optional` then the return value is undefined. isReadOnly(ELContext The context of this evaluation. context, Object The base object whose property value is to be analyzed, or `null` to analyze a top-level variable. base, Object The property or variable to return the read-only status for. property) Implements abstract jakarta.el.ELResolver.isReadOnly. For a given `base` and `property`, attempts to determine whether a call to `setValue` will always fail.
public void	setValue(ELContext The context of this evaluation. context, Object The base object whose property value is to be set, or `null` to set a top-level variable. base, Object The property or variable to be set. property, Object The value to set the property or variable to. value) Implements abstract jakarta.el.ELResolver.setValue. Attempts to set the value of the given `property` object on the given `base` object.

OptionalELResolver	back to summary
public OptionalELResolver()

Method Detail

convertToType back to summary

convertToType	back to summary
public <T> T convertToType(ELContext context, Object obj, Class<T> type) Overrides jakarta.el.ELResolver.convertToType. Doc from jakarta.el.ELResolver.convertToType. Converts an object to a specific type. An `ELException` is thrown if an error occurs during the conversion. Parameters context:ELContext The context of this evaluation. obj:Object The object to convert. type:Class<T> The target type for the conversion. Returns:T If the base object is an `Optional` and `Optional#isEmpty()` returns `true` then this method returns the result of coercing `null` to the requested `type`. If the base object is an `Optional` and `Optional#isPresent()` returns `true` then this method returns the result of coercing `Optional#get()` to the requested `type`. If the base object is not an `Optional` then the return value is undefined. Annotations @Override

public <T> T convertToType(ELContext context, Object obj, Class<T> type)

Overrides jakarta.el.ELResolver.convertToType.

Doc from jakarta.el.ELResolver.convertToType.

Converts an object to a specific type.

An ELException is thrown if an error occurs during the conversion.

Parameters

context:ELContext: The context of this evaluation.
obj:Object: The object to convert.
type:Class<T>: The target type for the conversion.

Returns:T

If the base object is an Optional and Optional#isEmpty() returns true then this method returns the result of coercing null to the requested type.

If the base object is an Optional and Optional#isPresent() returns true then this method returns the result of coercing Optional#get() to the requested type.

If the base object is not an Optional then the return value is undefined.

Annotations

@Override

getCommonPropertyType back to summary

getCommonPropertyType	back to summary
public Class<?> getCommonPropertyType(ELContext context, Object base) Implements abstract jakarta.el.ELResolver.getCommonPropertyType. Doc from jakarta.el.ELResolver.getCommonPropertyType. Returns the most general type that this resolver accepts for the `property` argument, given a `base` object. One use for this method is to assist tools in auto-completion. This assists tools in auto-completion and also provides a way to express that the resolver accepts a primitive value, such as an integer index into an array. For example, the `ArrayELResolver` will accept any `int` as a `property`, so the return value would be `Integer.class`. Parameters context:ELContext The context of this evaluation. base:Object The base object to return the most general property type for, or `null` to enumerate the set of top-level variables that this resolver can evaluate. Returns:Class<?> If the base object is an `Optional` this method always returns `Object.class`. If the base object is not an `Optional` then the return value is undefined. Annotations @Override

public Class<?> getCommonPropertyType(ELContext context, Object base)

Implements abstract jakarta.el.ELResolver.getCommonPropertyType.

Doc from jakarta.el.ELResolver.getCommonPropertyType.

Returns the most general type that this resolver accepts for the property argument, given a base object. One use for this method is to assist tools in auto-completion.

This assists tools in auto-completion and also provides a way to express that the resolver accepts a primitive value, such as an integer index into an array. For example, the ArrayELResolver will accept any int as a property, so the return value would be Integer.class.

Parameters

context:ELContext: The context of this evaluation.
base:Object: The base object to return the most general property type for, or null to enumerate the set of top-level variables that this resolver can evaluate.

Returns:Class<?>

If the base object is an Optional this method always returns Object.class.

If the base object is not an Optional then the return value is undefined.

Annotations

@Override

getType back to summary

getType	back to summary
public Class<?> getType(ELContext context, Object base, Object property) Implements abstract jakarta.el.ELResolver.getType. Doc from jakarta.el.ELResolver.getType. For a given `base` and `property`, attempts to identify the most general type that is acceptable for an object to be passed as the `value` parameter in a future call to the `setValue` method. If this resolver handles the given (base, property) pair, the `propertyResolved` property of the `ELContext` object must be set to `true` by the resolver, before returning. If this property is not `true` after this method is called, the caller should ignore the return value. This is not always the same as `getValue().getClass()`. For example, in the case of an `ArrayELResolver`, the `getType` method will return the element type of the array, which might be a superclass of the type of the actual element that is currently in the specified array element. If the resolver or the property is read-only, this method must return `null`. Parameters context:ELContext The context of this evaluation. base:Object The base object whose property value is to be analyzed, or `null` to analyze a top-level variable. property:Object The property or variable to return the acceptable type for. Returns:Class<?> If the base object is an `Optional` this method always returns `null` since instances of this resolver are always read-only. If the base object is not an `Optional` then the return value is undefined. Annotations @Override

public Class<?> getType(ELContext context, Object base, Object property)

Implements abstract jakarta.el.ELResolver.getType.

Doc from jakarta.el.ELResolver.getType.

For a given base and property, attempts to identify the most general type that is acceptable for an object to be passed as the value parameter in a future call to the setValue method.

If this resolver handles the given (base, property) pair, the propertyResolved property of the ELContext object must be set to true by the resolver, before returning. If this property is not true after this method is called, the caller should ignore the return value.

This is not always the same as getValue().getClass(). For example, in the case of an ArrayELResolver, the getType method will return the element type of the array, which might be a superclass of the type of the actual element that is currently in the specified array element.

If the resolver or the property is read-only, this method must return null.

Parameters

context:ELContext: The context of this evaluation.
base:Object: The base object whose property value is to be analyzed, or null to analyze a top-level variable.
property:Object: The property or variable to return the acceptable type for.

Returns:Class<?>

If the base object is an Optional this method always returns null since instances of this resolver are always read-only.

If the base object is not an Optional then the return value is undefined.

Annotations

@Override

getValue back to summary

getValue	back to summary
public Object getValue(ELContext context, Object base, Object property) Implements abstract jakarta.el.ELResolver.getValue. Doc from jakarta.el.ELResolver.getValue. Attempts to resolve the given `property` object on the given `base` object. If this resolver handles the given (base, property) pair, the `propertyResolved` property of the `ELContext` object must be set to `true` by the resolver, before returning. If this property is not `true` after this method is called, the caller should ignore the return value. Parameters context:ELContext The context of this evaluation. base:Object The base object whose property value is to be returned, or `null` to resolve a top-level variable. property:Object The property or variable to be resolved. Returns:Object If the base object is an `Optional` and `Optional#isEmpty()` returns `true` then the resulting value is `null`. If the base object is an `Optional`, `Optional#isPresent()` returns `true` and the property is `null` then the resulting value is the result of calling `Optional#get()` on the base object. If the base object is an `Optional`, `Optional#isPresent()` returns `true` and the property is not `null` then the resulting value is the result of calling `ELResolver#getValue(ELContext, Object, Object)` using the `ELResolver` obtained from `ELContext#getELResolver()` with the following parameters: The `ELContext` is the current context The base object is the result of calling `Optional#get()` on the current base object The property object is the current property object If the base object is not an `Optional` then the return value is undefined. Annotations @Override

public Object getValue(ELContext context, Object base, Object property)

Implements abstract jakarta.el.ELResolver.getValue.

Doc from jakarta.el.ELResolver.getValue.

Attempts to resolve the given property object on the given base object.

Parameters

context:ELContext: The context of this evaluation.
base:Object: The base object whose property value is to be returned, or null to resolve a top-level variable.
property:Object: The property or variable to be resolved.

Returns:Object

If the base object is an Optional and Optional#isEmpty() returns true then the resulting value is null.

If the base object is an Optional, Optional#isPresent() returns true and the property is null then the resulting value is the result of calling Optional#get() on the base object.

If the base object is an Optional, Optional#isPresent() returns true and the property is not null then the resulting value is the result of calling ELResolver#getValue(ELContext, Object, Object) using the ELResolver obtained from ELContext#getELResolver() with the following parameters:

The ELContext is the current context
The base object is the result of calling Optional#get() on the current base object
The property object is the current property object

If the base object is not an Optional then the return value is undefined.

Annotations

@Override

invoke back to summary

invoke	back to summary
public Object invoke(ELContext context, Object base, Object method, Class<?>[] paramTypes, Object[] params) Overrides jakarta.el.ELResolver.invoke. Doc from jakarta.el.ELResolver.invoke. Attempts to resolve and invoke the given `method` on the given `base` object. If this resolver handles the given (base, method) pair, the `propertyResolved` property of the `ELContext` object must be set to `true` by the resolver, before returning. If this property is not `true` after this method is called, the caller should ignore the return value. A default implementation is provided that returns null so that existing classes that extend ELResolver can continue to function. Parameters context:ELContext The context of this evaluation. base:Object The bean on which to invoke the method method:Object The simple name of the method to invoke. Will be coerced to a `String`. paramTypes:Class<?>[] 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:Object[] The parameters to pass to the method, or `null` if no parameters. Returns:Object If the base object is an `Optional` and `Optional#isEmpty()` returns `true` then this method returns `null`. If the base object is an `Optional` and `Optional#isPresent()` returns `true` then this method returns the result of invoking the specified method on the object obtained by calling `Optional#get()` with the specified parameters. If the base object is not an `Optional` then the return value is undefined. Annotations @Override

public Object invoke(ELContext context, Object base, Object method, Class<?>[] paramTypes, Object[] params)

Overrides jakarta.el.ELResolver.invoke.

Doc from jakarta.el.ELResolver.invoke.

Attempts to resolve and invoke the given method on the given base object.

If this resolver handles the given (base, method) pair, the propertyResolved property of the ELContext object must be set to true by the resolver, before returning. If this property is not true after this method is called, the caller should ignore the return value.

A default implementation is provided that returns null so that existing classes that extend ELResolver can continue to function.

Parameters

context:ELContext: The context of this evaluation.
base:Object: The bean on which to invoke the method
method:Object: The simple name of the method to invoke. Will be coerced to a String.
paramTypes:Class<?>[]: 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:Object[]: The parameters to pass to the method, or null if no parameters.

Returns:Object

If the base object is an Optional and Optional#isEmpty() returns true then this method returns null.

If the base object is an Optional and Optional#isPresent() returns true then this method returns the result of invoking the specified method on the object obtained by calling Optional#get() with the specified parameters.

If the base object is not an Optional then the return value is undefined.

Annotations

@Override

isReadOnly back to summary

isReadOnly	back to summary
public boolean isReadOnly(ELContext context, Object base, Object property) Implements abstract jakarta.el.ELResolver.isReadOnly. Doc from jakarta.el.ELResolver.isReadOnly. For a given `base` and `property`, attempts to determine whether a call to `setValue` will always fail. If this resolver handles the given (base, property) pair, the `propertyResolved` property of the `ELContext` object must be set to `true` by the resolver, before returning. If this property is not `true` after this method is called, the caller should ignore the return value. Parameters context:ELContext The context of this evaluation. base:Object The base object whose property value is to be analyzed, or `null` to analyze a top-level variable. property:Object The property or variable to return the read-only status for. Returns:boolean If the base object is an `Optional` this method always returns `true` since instances of this resolver are always read-only. If the base object is not an `Optional` then the return value is undefined. Annotations @Override

public boolean isReadOnly(ELContext context, Object base, Object property)

Implements abstract jakarta.el.ELResolver.isReadOnly.

Doc from jakarta.el.ELResolver.isReadOnly.

For a given base and property, attempts to determine whether a call to setValue will always fail.

Parameters

context:ELContext: The context of this evaluation.
base:Object: The base object whose property value is to be analyzed, or null to analyze a top-level variable.
property:Object: The property or variable to return the read-only status for.

Returns:boolean

If the base object is an Optional this method always returns true since instances of this resolver are always read-only.

If the base object is not an Optional then the return value is undefined.

Annotations

@Override

setValue back to summary

setValue	back to summary
public void setValue(ELContext context, Object base, Object property, Object value) Implements abstract jakarta.el.ELResolver.setValue. Doc from jakarta.el.ELResolver.setValue. Attempts to set the value of the given `property` object on the given `base` object. If this resolver handles the given (base, property) pair, the `propertyResolved` property of the `ELContext` object must be set to `true` by the resolver, before returning. If this property is not `true` after this method is called, the caller can safely assume no value has been set. If the base object is an `Optional` this method always throws a `PropertyNotWritableException` since instances of this resolver are always read-only. Parameters context:ELContext The context of this evaluation. base:Object The base object whose property value is to be set, or `null` to set a top-level variable. property:Object The property or variable to be set. value:Object The value to set the property or variable to. Annotations @Override

public void setValue(ELContext context, Object base, Object property, Object value)

Implements abstract jakarta.el.ELResolver.setValue.

Doc from jakarta.el.ELResolver.setValue.

Attempts to set the value of the given property object on the given base object.

If the base object is an Optional this method always throws a PropertyNotWritableException since instances of this resolver are always read-only.

Parameters

context:ELContext: The context of this evaluation.
base:Object: The base object whose property value is to be set, or null to set a top-level variable.
property:Object: The property or variable to be set.
value:Object: The value to set the property or variable to.

Annotations

@Override

public Class OptionalELResolver

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Constructor Detail

Method Detail