Package de.odysseus.el
Class TreeValueExpression
- java.lang.Object
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- javax.el.Expression
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- javax.el.ValueExpression
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- de.odysseus.el.TreeValueExpression
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- All Implemented Interfaces:
java.io.Serializable
public final class TreeValueExpression extends javax.el.ValueExpression
A value expression is ready to be evaluated (by calling eithergetType(ELContext)
,getValue(ELContext)
,isReadOnly(ELContext)
orsetValue(ELContext, Object)
. Instances of this class are usually created using anExpressionFactoryImpl
.- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description private Bindings
bindings
private TreeBuilder
builder
private boolean
deferred
private java.lang.String
expr
private ExpressionNode
node
private static long
serialVersionUID
private java.lang.String
structure
private java.lang.Class<?>
type
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Constructor Summary
Constructors Constructor Description TreeValueExpression(TreeStore store, javax.el.FunctionMapper functions, javax.el.VariableMapper variables, TypeConverter converter, java.lang.String expr, java.lang.Class<?> type)
Create a new value expression.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
dump(java.io.PrintWriter writer)
Print the parse tree.boolean
equals(java.lang.Object obj)
Expressions are compared using the concept of a structural id: variable and function names are anonymized such that two expressions with same tree structure will also have the same structural id and vice versa.java.lang.Class<?>
getExpectedType()
java.lang.String
getExpressionString()
private java.lang.String
getStructuralId()
java.lang.Class<?>
getType(javax.el.ELContext context)
Evaluates the expression as an lvalue and answers the result type.java.lang.Object
getValue(javax.el.ELContext context)
Evaluates the expression as an rvalue and answers the result.javax.el.ValueReference
getValueReference(javax.el.ELContext context)
int
hashCode()
boolean
isDeferred()
Answertrue
if this is a deferred expression (containing sub-expressions starting with#{
)boolean
isLeftValue()
Answertrue
if this could be used as an lvalue.boolean
isLiteralText()
boolean
isReadOnly(javax.el.ELContext context)
Evaluates the expression as an lvalue and determines ifsetValue(ELContext, Object)
will always fail.private void
readObject(java.io.ObjectInputStream in)
void
setValue(javax.el.ELContext context, java.lang.Object value)
Evaluates the expression as an lvalue and assigns the given value.java.lang.String
toString()
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Field Detail
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serialVersionUID
private static final long serialVersionUID
- See Also:
- Constant Field Values
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builder
private final TreeBuilder builder
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bindings
private final Bindings bindings
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expr
private final java.lang.String expr
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type
private final java.lang.Class<?> type
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deferred
private final boolean deferred
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node
private transient ExpressionNode node
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structure
private java.lang.String structure
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Constructor Detail
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TreeValueExpression
public TreeValueExpression(TreeStore store, javax.el.FunctionMapper functions, javax.el.VariableMapper variables, TypeConverter converter, java.lang.String expr, java.lang.Class<?> type)
Create a new value expression.- Parameters:
store
- used to get the parse tree from.functions
- the function mapper used to bind functionsvariables
- the variable mapper used to bind variablesexpr
- the expression stringtype
- the expected type (may benull
)
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Method Detail
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getStructuralId
private java.lang.String getStructuralId()
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getExpectedType
public java.lang.Class<?> getExpectedType()
- Specified by:
getExpectedType
in classjavax.el.ValueExpression
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getExpressionString
public java.lang.String getExpressionString()
- Specified by:
getExpressionString
in classjavax.el.Expression
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getType
public java.lang.Class<?> getType(javax.el.ELContext context) throws javax.el.ELException
Evaluates the expression as an lvalue and answers the result type.- Specified by:
getType
in classjavax.el.ValueExpression
- Parameters:
context
- used to resolve properties (base.property
andbase[property]
) and to determine the result from the last base/property pair- Returns:
- lvalue evaluation type or
null
for rvalue expressions - Throws:
javax.el.ELException
- if evaluation fails (e.g. property not found, type conversion failed, ...)
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getValue
public java.lang.Object getValue(javax.el.ELContext context) throws javax.el.ELException
Evaluates the expression as an rvalue and answers the result.- Specified by:
getValue
in classjavax.el.ValueExpression
- Parameters:
context
- used to resolve properties (base.property
andbase[property]
) and to determine the result from the last base/property pair- Returns:
- rvalue evaluation result
- Throws:
javax.el.ELException
- if evaluation fails (e.g. property not found, type conversion failed, ...)
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isReadOnly
public boolean isReadOnly(javax.el.ELContext context) throws javax.el.ELException
Evaluates the expression as an lvalue and determines ifsetValue(ELContext, Object)
will always fail.- Specified by:
isReadOnly
in classjavax.el.ValueExpression
- Parameters:
context
- used to resolve properties (base.property
andbase[property]
) and to determine the result from the last base/property pair- Returns:
true
ifsetValue(ELContext, Object)
always fails.- Throws:
javax.el.ELException
- if evaluation fails (e.g. property not found, type conversion failed, ...)
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setValue
public void setValue(javax.el.ELContext context, java.lang.Object value) throws javax.el.ELException
Evaluates the expression as an lvalue and assigns the given value.- Specified by:
setValue
in classjavax.el.ValueExpression
- Parameters:
context
- used to resolve properties (base.property
andbase[property]
) and to perform the assignment to the last base/property pair- Throws:
javax.el.ELException
- if evaluation fails (e.g. property not found, type conversion failed, assignment failed...)
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isLiteralText
public boolean isLiteralText()
- Specified by:
isLiteralText
in classjavax.el.Expression
- Returns:
true
if this is a literal text expression
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getValueReference
public javax.el.ValueReference getValueReference(javax.el.ELContext context)
- Overrides:
getValueReference
in classjavax.el.ValueExpression
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isLeftValue
public boolean isLeftValue()
Answertrue
if this could be used as an lvalue. This is the case for eval expressions consisting of a simple identifier or a nonliteral prefix, followed by a sequence of property operators (.
or[]
)
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isDeferred
public boolean isDeferred()
Answertrue
if this is a deferred expression (containing sub-expressions starting with#{
)
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equals
public boolean equals(java.lang.Object obj)
Expressions are compared using the concept of a structural id: variable and function names are anonymized such that two expressions with same tree structure will also have the same structural id and vice versa. Two value expressions are equal if- their structural id's are equal
- their bindings are equal
- their expected types are equal
- Specified by:
equals
in classjavax.el.Expression
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hashCode
public int hashCode()
- Specified by:
hashCode
in classjavax.el.Expression
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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dump
public void dump(java.io.PrintWriter writer)
Print the parse tree.- Parameters:
writer
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readObject
private void readObject(java.io.ObjectInputStream in) throws java.io.IOException, java.lang.ClassNotFoundException
- Throws:
java.io.IOException
java.lang.ClassNotFoundException
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