org.eclipse.jdt.core.dom
Class Expression

java.lang.Object
  org.eclipse.jdt.core.dom.ASTNode
      org.eclipse.jdt.core.dom.Expression

Direct Known Subclasses:

Annotation, ArrayAccess, ArrayCreation, ArrayInitializer, Assignment, BooleanLiteral, CastExpression, CharacterLiteral, ClassInstanceCreation, ConditionalExpression, FieldAccess, InfixExpression, InstanceofExpression, MethodInvocation, Name, NullLiteral, NumberLiteral, ParenthesizedExpression, PostfixExpression, PrefixExpression, StringLiteral, SuperFieldAccess, SuperMethodInvocation, ThisExpression, TypeLiteral, VariableDeclarationExpression

public abstract class Expression
extends ASTNode

Abstract base class of AST nodes that represent expressions. There are several kinds of expressions.

 Expression:
    Name
    IntegerLiteral (includes decimal, hex, and octal forms; and long)
    FloatingPointLiteral (includes both float and double)
    CharacterLiteral
    NullLiteral
    BooleanLiteral
    StringLiteral
    TypeLiteral
    ThisExpression
    SuperFieldAccess
    FieldAccess
    Assignment
    ParenthesizedExpression
    ClassInstanceCreation
    ArrayCreation
    ArrayInitializer
    MethodInvocation
    SuperMethodInvocation
    ArrayAccess
    InfixExpression
    InstanceofExpression
    ConditionalExpression
    PostfixExpression
    PrefixExpression
    CastExpression
    VariableDeclarationExpression
 

Since:

2.0

Field Summary

Fields inherited from class org.eclipse.jdt.core.dom.ASTNode

ANNOTATION_TYPE_DECLARATION, ANNOTATION_TYPE_MEMBER_DECLARATION, ANONYMOUS_CLASS_DECLARATION, ARRAY_ACCESS, ARRAY_CREATION, ARRAY_INITIALIZER, ARRAY_TYPE, ASSERT_STATEMENT, ASSIGNMENT, BLOCK, BLOCK_COMMENT, BOOLEAN_LITERAL, BREAK_STATEMENT, CAST_EXPRESSION, CATCH_CLAUSE, CHARACTER_LITERAL, CLASS_INSTANCE_CREATION, COMPILATION_UNIT, CONDITIONAL_EXPRESSION, CONSTRUCTOR_INVOCATION, CONTINUE_STATEMENT, DO_STATEMENT, EMPTY_STATEMENT, ENHANCED_FOR_STATEMENT, ENUM_CONSTANT_DECLARATION, ENUM_DECLARATION, EXPRESSION_STATEMENT, FIELD_ACCESS, FIELD_DECLARATION, FOR_STATEMENT, IF_STATEMENT, IMPORT_DECLARATION, INFIX_EXPRESSION, INITIALIZER, INSTANCEOF_EXPRESSION, JAVADOC, LABELED_STATEMENT, LINE_COMMENT, MALFORMED, MARKER_ANNOTATION, MEMBER_REF, MEMBER_VALUE_PAIR, METHOD_DECLARATION, METHOD_INVOCATION, METHOD_REF, METHOD_REF_PARAMETER, MODIFIER, NORMAL_ANNOTATION, NULL_LITERAL, NUMBER_LITERAL, ORIGINAL, PACKAGE_DECLARATION, PARAMETERIZED_TYPE, PARENTHESIZED_EXPRESSION, POSTFIX_EXPRESSION, PREFIX_EXPRESSION, PRIMITIVE_TYPE, PROTECT, QUALIFIED_NAME, QUALIFIED_TYPE, RECOVERED, RETURN_STATEMENT, SIMPLE_NAME, SIMPLE_TYPE, SINGLE_MEMBER_ANNOTATION, SINGLE_VARIABLE_DECLARATION, STRING_LITERAL, SUPER_CONSTRUCTOR_INVOCATION, SUPER_FIELD_ACCESS, SUPER_METHOD_INVOCATION, SWITCH_CASE, SWITCH_STATEMENT, SYNCHRONIZED_STATEMENT, TAG_ELEMENT, TEXT_ELEMENT, THIS_EXPRESSION, THROW_STATEMENT, TRY_STATEMENT, TYPE_DECLARATION, TYPE_DECLARATION_STATEMENT, TYPE_LITERAL, TYPE_PARAMETER, VARIABLE_DECLARATION_EXPRESSION, VARIABLE_DECLARATION_FRAGMENT, VARIABLE_DECLARATION_STATEMENT, WHILE_STATEMENT, WILDCARD_TYPE

Method Summary

boolean	resolveBoxing() Returns whether this expression node is the site of a boxing conversion (JLS3 5.1.7).
java.lang.Object	resolveConstantExpressionValue() Resolves and returns the compile-time constant expression value as specified in JLS2 15.28, if this expression has one.
ITypeBinding	resolveTypeBinding() Resolves and returns the binding for the type of this expression.
boolean	resolveUnboxing() Returns whether this expression node is the site of an unboxing conversion (JLS3 5.1.8).

Methods inherited from class org.eclipse.jdt.core.dom.ASTNode

accept, copySubtree, copySubtrees, delete, equals, getAST, getFlags, getLength, getLocationInParent, getNodeType, getParent, getProperty, getRoot, getStartPosition, getStructuralProperty, hashCode, nodeClassForType, properties, setFlags, setProperty, setSourceRange, setStructuralProperty, structuralPropertiesForType, subtreeBytes, subtreeMatch, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Method Detail

resolveConstantExpressionValue

public final java.lang.Object resolveConstantExpressionValue()

Resolves and returns the compile-time constant expression value as specified in JLS2 15.28, if this expression has one. Constant expression values are unavailable unless bindings are requested when the AST is being built. If the type of the value is a primitive type, the result is the boxed equivalent (i.e., int returned as an Integer); if the type of the value is String, the result is the string itself. If the expression does not have a compile-time constant expression value, the result is null.

Resolving constant expressions takes into account the value of simple and qualified names that refer to constant variables (JLS2 4.12.4).

Note 1: enum constants are not considered constant expressions. The result is always null for these.

Note 2: Compile-time constant expressions cannot denote null. So technically NullLiteral nodes are not constant expressions. The result is null for these nonetheless.

Returns:

the constant expression value, or null if this expression has no constant expression value or if bindings were not requested when the AST was created

Since:

3.1

resolveTypeBinding

public final ITypeBinding resolveTypeBinding()

Resolves and returns the binding for the type of this expression.

Note that bindings are generally unavailable unless requested when the AST is being built.

Returns:

the binding for the type of this expression, or null if the type cannot be resolved

resolveBoxing

public final boolean resolveBoxing()

Returns whether this expression node is the site of a boxing conversion (JLS3 5.1.7). This information is available only when bindings are requested when the AST is being built.

Returns:

true if this expression is the site of a boxing conversion, or false if either no boxing conversion is involved or if bindings were not requested when the AST was created

Since:

3.1

resolveUnboxing

public final boolean resolveUnboxing()

Returns whether this expression node is the site of an unboxing conversion (JLS3 5.1.8). This information is available only when bindings are requested when the AST is being built.

Returns:

true if this expression is the site of an unboxing conversion, or false if either no unboxing conversion is involved or if bindings were not requested when the AST was created

Since:

3.1