public class ASTParser extends Object
Example: Create basic AST from source string
char[] source = ...; ASTParser parser = ASTParser.newParser(AST.JLS3); // handles JDK 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6 parser.setSource(source); // In order to parse 1.5 code, some compiler options need to be set to 1.5 Map options = JavaCore.getOptions(); JavaCore.setComplianceOptions(JavaCore.VERSION_1_5, options); parser.setCompilerOptions(options); CompilationUnit result = (CompilationUnit) parser.createAST(null);Once a configured parser instance has been used to create an AST, the settings are automatically reset to their defaults, ready for the parser instance to be reused.
There are a number of configurable features:
char[]
,
ICompilationUnit
,
or IClassFile
, and limited
to a specified subrange.Modifier and Type | Field and Description |
---|---|
static int |
K_CLASS_BODY_DECLARATIONS
Kind constant used to request that the source be parsed
as a sequence of class body declarations.
|
static int |
K_COMPILATION_UNIT
Kind constant used to request that the source be parsed
as a compilation unit.
|
static int |
K_EXPRESSION
Kind constant used to request that the source be parsed
as a single expression.
|
static int |
K_STATEMENTS
Kind constant used to request that the source be parsed
as a sequence of statements.
|
Modifier and Type | Method and Description |
---|---|
ASTNode |
createAST(IProgressMonitor monitor)
Creates an abstract syntax tree.
|
void |
createASTs(ICompilationUnit[] compilationUnits,
String[] bindingKeys,
ASTRequestor requestor,
IProgressMonitor monitor)
Creates ASTs for a batch of compilation units.
|
void |
createASTs(String[] sourceFilePaths,
String[] encodings,
String[] bindingKeys,
FileASTRequestor requestor,
IProgressMonitor monitor)
Creates ASTs for a batch of compilation units.
|
IBinding[] |
createBindings(IJavaElement[] elements,
IProgressMonitor monitor)
Creates bindings for a batch of Java elements.
|
static ASTParser |
newParser(int level)
Creates a new object for creating a Java abstract syntax tree
(AST) following the specified set of API rules.
|
void |
setBindingsRecovery(boolean enabled)
Requests that the compiler should perform bindings recovery.
|
void |
setCompilerOptions(Map options)
Sets the compiler options to be used when parsing.
|
void |
setEnvironment(String[] classpathEntries,
String[] sourcepathEntries,
String[] encodings,
boolean includeRunningVMBootclasspath)
Sets the environment to be used when no
IJavaProject is available. |
void |
setFocalPosition(int position)
Requests an abridged abstract syntax tree.
|
void |
setIgnoreMethodBodies(boolean enabled)
Requests an abstract syntax tree without method bodies.
|
void |
setKind(int kind)
Sets the kind of constructs to be parsed from the source.
|
void |
setProject(IJavaProject project)
Sets the Java project used when resolving bindings.
|
void |
setResolveBindings(boolean enabled)
Requests that the compiler should provide binding information for
the AST nodes it creates.
|
void |
setSource(char[] source)
Sets the source code to be parsed.
|
void |
setSource(IClassFile source)
Sets the source code to be parsed.
|
void |
setSource(ICompilationUnit source)
Sets the source code to be parsed.
|
void |
setSource(ITypeRoot source)
Sets the source code to be parsed.
|
void |
setSourceRange(int offset,
int length)
Sets the subrange of the source code to be parsed.
|
void |
setStatementsRecovery(boolean enabled)
Requests that the compiler should perform statements recovery.
|
void |
setUnitName(String unitName)
Sets the name of the compilation unit that would hypothetically contains the
source string.
|
void |
setWorkingCopyOwner(WorkingCopyOwner owner)
Sets the working copy owner used when resolving bindings, where
null means the primary owner. |
public static final int K_EXPRESSION
public static final int K_STATEMENTS
public static final int K_CLASS_BODY_DECLARATIONS
public static final int K_COMPILATION_UNIT
public static ASTParser newParser(int level)
level
- the API level; one of the .JLS*
level constants
declared on AST
public void setBindingsRecovery(boolean enabled)
Default to false
.
This should be set to true only if bindings are resolved. It has no effect if there is no binding resolution.
enabled
- true
if incomplete bindings are expected,
and false
if only complete bindings are expected.IBinding.isRecovered()
public void setEnvironment(String[] classpathEntries, String[] sourcepathEntries, String[] encodings, boolean includeRunningVMBootclasspath)
IJavaProject
is available.
The user has to make sure that all the required types are included either in the classpath or source paths.
All the paths containing binary types must be included in the classpathEntries
whereas all paths containing
source types must be included in the sourcepathEntries
.
All paths in the classpathEntries
and sourcepathEntries
are absolute paths.
If the source paths contain units using a specific encoding (other than the platform encoding), then the
given encodings
must be set. When the encodings
is set to non null
, its length must
match the length of sourcepathEntries
or an IllegalArgumentException will be thrown.
If encodings
is not null
, the given sourcepathEntries
must not be null
.
classpathEntries
- the given classpath entries to be used to resolve bindingssourcepathEntries
- the given sourcepath entries to be used to resolve bindingsencodings
- the encodings of the corresponding sourcepath entries or null
if the platform encoding
can be used.includeRunningVMBootclasspath
- true
if the bootclasspath of the running VM must be prepended to the
given classpath and false
if the bootclasspath of the running VM should be ignored.IllegalArgumentException
- if the size of the given encodings is not equals to the size of the given
sourcepathEntries
public void setCompilerOptions(Map options)
Note that setSource(IClassFile)
,
setSource(ICompilationUnit)
,
and setProject(IJavaProject)
reset the compiler options
based on the Java project. In other cases, compiler options default
to JavaCore.getOptions()
. In either case, and especially
in the latter, the caller should carefully weight the consequences of
allowing compiler options to be defaulted as opposed to being
explicitly specified for the ASTParser
instance.
For instance, there is a compiler option called "Source Compatibility Mode"
which determines which JDK level the source code is expected to meet.
If you specify "1.4", then "assert" is treated as a keyword and disallowed
as an identifier; if you specify "1.3", then "assert" is allowed as an
identifier. So this particular setting has a major bearing on what is
considered syntactically legal. By explicitly specifying the setting,
the client control exactly how the parser works. On the other hand,
allowing default settings means the parsing behaves like other JDT tools.
options
- the table of options (key type: String
;
value type: String
), or null
to set it back to the defaultpublic void setResolveBindings(boolean enabled)
Defaults to false
(no bindings).
If setResolveBindings(true)
, the various names
and types appearing in the AST can be resolved to "bindings"
by calling the resolveBinding
methods. These bindings
draw connections between the different parts of a program, and
generally afford a more powerful vantage point for clients who wish to
analyze a program's structure more deeply. These bindings come at a
considerable cost in both time and space, however, and should not be
requested frivolously. The additional space is not reclaimed until the
AST, all its nodes, and all its bindings become garbage. So it is very
important to not retain any of these objects longer than absolutely
necessary. Bindings are resolved at the time the AST is created. Subsequent
modifications to the AST do not affect the bindings returned by
resolveBinding
methods in any way; these methods return the
same binding as before the AST was modified (including modifications
that rearrange subtrees by reparenting nodes).
If setResolveBindings(false)
, (the default), the analysis
does not go beyond parsing and building the tree, and all
resolveBinding
methods return null
from the outset.
When bindings are requested, instead of considering compilation units on disk only,
one can also supply a WorkingCopyOwner
. Working copies owned
by this owner take precedence over the underlying compilation units when looking
up names and drawing the connections.
Note that working copy owners are used only if the org.eclipse.jdt.core
bundle is initialized.
Binding information is obtained from the Java model.
This means that the compilation unit must be located relative to the
Java model. This happens automatically when the source code comes from
either setSource(ICompilationUnit)
or setSource(IClassFile)
.
When source is supplied by setSource(char[])
,
the location must be established explicitly by setting an environment using
setProject(IJavaProject)
or setEnvironment(String[], String[], String[], boolean)
and a unit name setUnitName(String)
.
Note that the compiler options that affect doc comment checking may also
affect whether any bindings are resolved for nodes within doc comments.
enabled
- true
if bindings are wanted,
and false
if bindings are not of interestpublic void setFocalPosition(int position)
When the given position
is a valid position within the source code of
the compilation unit, the resulting AST does not have nodes for
the entire compilation unit. Rather, the AST is only fleshed out
for the node that include the given source position. This kind of limited
AST is sufficient for certain purposes but totally unsuitable for others.
In places where it can be used, the limited AST offers the advantage of
being smaller and faster to construct.
The AST will include nodes for all of the compilation unit's
package, import, and top-level type declarations. It will also always contain
nodes for all the body declarations for those top-level types, as well
as body declarations for any member types. However, some of the body
declarations may be abridged. In particular, the statements ordinarily
found in the body of a method declaration node will not be included
(the block will be empty) unless the source position falls somewhere
within the source range of that method declaration node. The same is true
for initializer declarations; the statements ordinarily found in the body
of initializer node will not be included unless the source position falls
somewhere within the source range of that initializer declaration node.
Field declarations are never abridged. Note that the AST for the body of
that one unabridged method (or initializer) is 100% complete; it has all
its statements, including any local or anonymous type declarations
embedded within them. When the given position
is not located within
the source range of any body declaration of a top-level type, the AST
returned will be a skeleton that includes nodes for all and only the major
declarations; this kind of AST is still quite useful because it contains
all the constructs that introduce names visible to the world outside the
compilation unit.
This focal position is not used when the AST is built using
createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)
.
position
- a position into the corresponding body declarationpublic void setKind(int kind)
When the parse is successful the result returned includes the ASTs for the requested source:
K_COMPILATION_UNIT
: The result node
is a CompilationUnit
.K_CLASS_BODY_DECLARATIONS
: The result node
is a TypeDeclaration
whose
bodyDeclarations
are the new trees. Other aspects of the type declaration are unspecified.K_STATEMENTS
: The result node is a
Block
whose statements
are the new trees. Other aspects of the block are unspecified.K_EXPRESSION
: The result node is a subclass of
Expression
. Other aspects of the expression are unspecified.CompilationUnit
node, to allow the
client to retrieve the following pieces of information
available there:
source[offset]
through source[offset+length-1]
).source
; line positions are for the subrange scanned.CompilationUnit
node are unspecified, including
the exact arrangement of intervening nodes.
Lexical or syntax errors detected while parsing can result in
a result node being marked as MALFORMED
.
In more severe failure cases where the parser is unable to
recognize the input, this method returns
a CompilationUnit
node with at least the
compiler messages.
Each node in the subtree (other than the contrived nodes) carries source range(s) information relating back to positions in the given source (the given source itself is not remembered with the AST). The source range usually begins at the first character of the first token corresponding to the node; leading whitespace and comments are not included. The source range usually extends through the last character of the last token corresponding to the node; trailing whitespace and comments are not included. There are a handful of exceptions (including the various body declarations); the specification for these node type spells out the details. Source ranges nest properly: the source range for a child is always within the source range of its parent, and the source ranges of sibling nodes never overlap.
Binding information is only computed when kind
is
K_COMPILATION_UNIT
.
This kind is not used when the AST is built using
createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)
.
kind
- the kind of construct to parse: one of
K_COMPILATION_UNIT
,
K_CLASS_BODY_DECLARATIONS
,
K_EXPRESSION
,
K_STATEMENTS
public void setSource(char[] source)
This source is not used when the AST is built using
createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)
.
If this method is used, the user needs to specify compiler options explicitly using
setCompilerOptions(Map)
as 1.5 code will not be properly parsed without setting
the appropriate values for the compiler options: JavaCore.COMPILER_SOURCE
,
JavaCore.COMPILER_CODEGEN_TARGET_PLATFORM
, and JavaCore.COMPILER_COMPLIANCE
.
Otherwise the default values for the compiler options will be used to parse the given source.
source
- the source string to be parsed,
or null
if noneJavaCore.setComplianceOptions(String, Map)
public void setSource(ICompilationUnit source)
This method automatically sets the project (and compiler
options) based on the given compilation unit, in a manner
equivalent to setProject(source.getJavaProject())
.
This source is not used when the AST is built using
createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)
.
source
- the Java model compilation unit whose source code
is to be parsed, or null
if nonepublic void setSource(IClassFile source)
This method automatically sets the project (and compiler
options) based on the given compilation unit, in a manner
equivalent to setProject(source.getJavaProject())
.
If the given class file has no source attachment, the creation of the
ast will fail with an IllegalStateException
.
This source is not used when the AST is built using
createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)
.
source
- the Java model class file whose corresponding source code
is to be parsed, or null
if nonepublic void setSource(ITypeRoot source)
This method automatically sets the project (and compiler
options) based on the given compilation unit of class file, in a manner
equivalent to setProject(source.getJavaProject())
.
If the source is a class file without source attachment, the creation of the
ast will fail with an IllegalStateException
.
This source is not used when the AST is built using
createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)
.
source
- the Java model compilation unit or class file whose corresponding source code
is to be parsed, or null
if nonepublic void setSourceRange(int offset, int length)
offset
0 and length
-1).
This range is not used when the AST is built using
createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)
.
offset
- the index of the first character to parselength
- the number of characters to parse, or -1 if
the remainder of the source string is to be parsedpublic void setStatementsRecovery(boolean enabled)
Default to false
.
enabled
- true
if statements containing syntax errors are wanted,
and false
if these statements aren't wanted.public void setIgnoreMethodBodies(boolean enabled)
When ignore method bodies is enabled, all method bodies are discarded. This has no impact on the binding resolution.
This setting is not used when the kind used in setKind(int)
is either
K_EXPRESSION
or K_STATEMENTS
.
public void setWorkingCopyOwner(WorkingCopyOwner owner)
null
means the primary owner. Defaults to the primary owner.owner
- the owner of working copies that take precedence over underlying
compilation units, or null
if the primary owner should be usedpublic void setUnitName(String unitName)
This is used in conjunction with setSource(char[])
and setProject(IJavaProject)
to locate the compilation unit relative to a Java project.
Defaults to none (null
).
The name of the compilation unit must be supplied for resolving bindings.
This name should be suffixed by a dot ('.') followed by one of the
Java-like extensions
and match the name of the main (public) class or interface declared in the source.
This name must represent the full path of the unit inside the given project. For example, if the source declares a public class named "Foo" in a project "P" where the source folder is the project itself, the name of the compilation unit must be "/P/Foo.java". If the source declares a public class name "Bar" in a package "p1.p2" in a project "P" in a source folder "src", the name of the compilation unit must be "/P/src/p1/p2/Bar.java".
This unit name is not used when the AST is built using
createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)
.
unitName
- the name of the compilation unit that would contain the source
string, or null
if nonepublic void setProject(IJavaProject project)
This method automatically sets the compiler options based on the given project:
setCompilerOptions(project.getOptions(true));
See setCompilerOptions(Map)
for a discussion of
the pros and cons of using these options vs specifying
compiler options explicitly.
This setting is used in conjunction with setSource(char[])
.
For the purposes of resolving bindings, types declared in the
source string will hide types by the same name available
through the classpath of the given project.
Defaults to none (null
).
project
- the Java project used to resolve names, or
null
if nonepublic ASTNode createAST(IProgressMonitor monitor)
A successful call to this method returns all settings to their default values so the object is ready to be reused.
monitor
- the progress monitor used to report progress and request cancellation,
or null
if noneCompilationUnit
in the case of severe parsing errorsIllegalStateException
- if the settings provided
are insufficient, contradictory, or otherwise unsupportedpublic void createASTs(ICompilationUnit[] compilationUnits, String[] bindingKeys, ASTRequestor requestor, IProgressMonitor monitor)
When bindings are being resolved, processing a batch of compilation units is more efficient because much of the work involved in resolving bindings can be shared.
When bindings are being resolved, all compilation units must
come from the same Java project, which must be set beforehand
with setProject
.
The compilation units are processed one at a time in no specified order. For each of the compilation units in turn,
ASTParser.createAST
is called to parse it
and create a corresponding AST. The calls to
ASTParser.createAST
all employ the same settings.ASTRequestor.acceptAST
is called passing the compilation unit and the corresponding AST to requestor
.
Note also the following parser parameters are used, regardless of what may have been specified:
K_COMPILATION_UNIT
(0, -1)
The bindingKeys
parameter specifies bindings keys
(IBinding.getKey()
) that are to be looked up. These keys may
be for elements either inside or outside the set of compilation
units being processed. When bindings are being resolved,
the keys and corresponding bindings (or null
if none) are
passed to ASTRequestor.acceptBinding
.
Note that binding keys for elements outside the set of compilation units being processed
are looked up after all ASTRequestor.acceptAST
callbacks have been made.
Binding keys for elements inside the set of compilation units being processed
are looked up and reported right after the corresponding
ASTRequestor.acceptAST
callback has been made.
No ASTRequestor.acceptBinding
callbacks are made unless
bindings are being resolved.
A successful call to this method returns all settings to their default values so the object is ready to be reused.
compilationUnits
- the compilation units to create ASTs forbindingKeys
- the binding keys to create bindings forrequestor
- the AST requestor that collects abstract syntax trees and bindingsmonitor
- the progress monitor used to report progress and request cancellation,
or null
if noneIllegalStateException
- if the settings provided
are insufficient, contradictory, or otherwise unsupportedpublic void createASTs(String[] sourceFilePaths, String[] encodings, String[] bindingKeys, FileASTRequestor requestor, IProgressMonitor monitor)
When bindings are being resolved, all compilation units are resolved using
the same environment, which must be set beforehand
with setEnvironment
.
The compilation units are processed one at a time in no
specified order. For each of the compilation units in turn,
ASTParser.createAST
is called to parse it
and create a corresponding AST. The calls to
ASTParser.createAST
all employ the same settings.FileASTRequestor.acceptAST
is called passing
the compilation unit path and the corresponding AST to requestor
. The compilation unit path is the same
path that is passed into the given sourceFilePaths
parameter.
Note also the following parser parameters are used, regardless of what may have been specified:
K_COMPILATION_UNIT
(0, -1)
The bindingKeys
parameter specifies bindings keys
(IBinding.getKey()
) that are to be looked up. These keys may
be for elements either inside or outside the set of compilation
units being processed. When bindings are being resolved,
the keys and corresponding bindings (or null
if none) are
passed to FileASTRequestor.acceptBinding
. Note that binding keys
for elements outside the set of compilation units being processed are looked up
after all ASTRequestor.acceptAST
callbacks have been made.
Binding keys for elements inside the set of compilation units being processed
are looked up and reported right after the corresponding
FileASTRequestor.acceptAST
callback has been made.
No FileASTRequestor.acceptBinding
callbacks are made unless
bindings are being resolved.
A successful call to this method returns all settings to their default values so the object is ready to be reused.
The given encodings
are used to properly parse the given source units. If the platform encoding is sufficient,
then the given encodings can be set to null
.
sourceFilePaths
- the compilation units to create ASTs forencodings
- the given encoding for the source unitsbindingKeys
- the binding keys to create bindings forrequestor
- the AST requestor that collects abstract syntax trees and bindingsmonitor
- the progress monitor used to report progress and request cancellation,
or null
if noneIllegalStateException
- if the settings provided
are insufficient, contradictory, or otherwise unsupportedpublic IBinding[] createBindings(IJavaElement[] elements, IProgressMonitor monitor)
These elements are either
enclosed in ICompilationUnits
or in IClassFiles
.
All enclosing compilation units and class files must
come from the same Java project, which must be set beforehand
with setProject
.
All elements must exist. If one doesn't exist, an IllegalStateException
is thrown.
The returned array has the same size as the given elements array. At a given position
it contains the binding of the corresponding Java element, or null
if no binding could be created.
Note also the following parser parameters are used, regardless of what may have been specified:
true
K_COMPILATION_UNIT
(0, -1)
A successful call to this method returns all settings to their default values so the object is ready to be reused.
elements
- the Java elements to create bindings fornull
s
if some bindings could not be createdIllegalStateException
- if the settings provided
are insufficient, contradictory, or otherwise unsupported
Copyright (c) 2000, 2015 Eclipse Contributors and others. All rights reserved.Guidelines for using Eclipse APIs.