JAXB OSGI 4.0.9 · com.sun.codemodel · APIdia, the JavaDoc alternative

Library for generating Java source code

CodeModel is a library that allows you to generate Java source code in a type-safe fashion.

With CodeModel, you build the java source code by first building AST, then writing it out as text files that is Java source files. The AST looks like this:

You bulid this tree mostly from top-down. So, you first create a new com.sun.codemodel.JDefinedClass from com.sun.codemodel.JCodeModel, then you create a com.sun.codemodel.JMethod from com.sun.codemodel.JDefinedClass, and so on.

This design brings the following benefits:

source code can be written in random order
generated source code nicely imports other classes
generated source code is lexically always correct (no unbalanced parenthesis, etc.)
code generation becomes relatively type-safe

The price you pay for that is increased memory footprint and the generation speed. See performance section for more discussions about the performance and possible improvements.

Using CodeModel

com.sun.codemodel.JCodeModel is the entry point to the library. See its javadoc for more details about how to use CodeModel.

Performance

Generally speaking, CodeModel is expected to be used in an environment where the resource constraint is not severe. Therefore, we haven't spent much effort in trying to make this library lean and mean.

That said, we did some benchmark and performance analysis. In case anyone is interested in making this library better performance wise, here's the findings.

java.util.Lists java.util.Maps, and other collections take up a lot of space. Allocating those things lazily is generally a good idea.

Compared to template-based code generator, the writing operation is slow, as it needs to traverse each AST node. Consider pre-encoding tokens (like 'public') to the target encoding, and consider exploting the subtree equivalence.

Modifier and Type	Interface and Description
public interface	JAnnotatable Annotatable program elements.
public interface	JAnnotationWriter<A extends Annotation> Base interface for typed annotation writer.
public interface	JAssignmentTarget Marker interface for code components that can be placed to the left of '=' in an assignment.
public interface	JClassContainer The common aspect of a package and a class.
public interface	JDeclaration Common interface for code components that can generate declarations of themselves.
public interface	JDocCommentable Program elements that can have Javadoc
public interface	JExpression A Java expression.
public interface	JGenerable Common interface for code components that can generate uses of themselves.
public interface	JGenerifiable Declarations that can have type variables.
public interface	JStatement Common interface for code components that can generate uses of themselves as statements.

Class Summary

Modifier and Type	Class and Description
public class	ClassType This helps enable whether the JDefinedClass is a Class or Interface or AnnotationTypeDeclaration or Enum
public abstract class	CodeWriter Receives generated code and writes to the appropriate storage.
public class	JAnnotationArrayMember Represents an arrays as annotation members This class implements `JAnnotatable` to allow new annotations to be added as a member of the array.
public class	JAnnotationClassValue Captures the Class or Enum value of the annotation.
public class	JAnnotationStringValue Captures the value of the annotation.
public class	JAnnotationUse Represents an annotation on a program element.
public abstract class	JAnnotationValue Things that can be values of an annotation element.
pack-priv class	JAnonymousClass Anonymous class quick hack.
public class	JArray array creation and initialization.
pack-priv class	JArrayClass Array class.
public class	JArrayCompRef array component reference.
public class	JAssignment Assignment statements, which are also expressions.
pack-priv class	JAtom JAtoms: Simple code components that merely generate themselves.
public class	JBlock A block of Java code, which may contain statements and local declarations.
pack-priv class	JBreak JBreak statement
public class	JCase Case statement
public class	JCast A cast operation.
public class	JCatchBlock Catch block for a try/catch/finally statement
public abstract class	JClass Represents a Java reference type, such as a class, an interface, an enum, an array type, a parameterized type.
public class	JClassAlreadyExistsException Indicates that the class is already created.
public class	JCodeModel Root of the code DOM.
public class	JCommentPart A part is a part of a javadoc comment, and it is a list of values.
public class	JConditional If statement, with optional else clause
pack-priv class	JContinue JContinue statement
public class	JDefinedClass A generated Java class/interface/enum/....
pack-priv class	JDirectClass A special `JClass` that represents an unknown class (except its name.)
public class	JDocComment JavaDoc comment.
public class	JDoLoop Do loops
public class	JEnumConstant Enum Constant.
public class	JExportsDirective Represents a Java module `exports` directive.
public abstract class	JExpr Factory methods that generate various `JExpression`s.
public abstract class	JExpressionImpl Provides default implementations for `JExpression`.
public class	JFieldRef Field Reference
public class	JFieldVar A field that can have a `JDocComment` associated with it
public class	JForEach ForEach Statement This will generate the code for statement based on the new j2se 1.5 j.l.s.
public class	JForLoop For statement
public class	JFormatter This is a utility class for managing indentation and other basic formatting for PrintWriter.
pack-priv abstract class	JGenerifiableImpl Implementation of `JGenerifiable`.
public class	JInvocation JMethod invocation
public class	JJavaName Utility methods that convert arbitrary strings into Java identifiers.
public class	JLabel Label that can be used for continue and break.
public class	JMethod Java method.
public class	JMod Modifier constants.
public class	JMods Modifier groups.
public class	JModule Represents a Java module.
public abstract class	JModuleDirective Represents a Java module directive.
pack-priv class	JNarrowedClass Represents `X<Y>`.
public class	JNullType Special class object that represents the type of "null".
public abstract class	JOp JClass for generating expressions containing operators
public class	JPackage A Java package.
public class	JPrimitiveType Java built-in primitive types.
public class	JRequiresDirective Represents a Java module `requires` directive.
public abstract class	JResourceFile Represents a resource file in the application-specific file format.
pack-priv class	JReturn A return statement
public class	JStringLiteral String literal.
public class	JSwitch Switch statement
pack-priv class	JThrow JThrow statement
public class	JTryBlock Try statement with Catch and/or Finally clause
public abstract class	JType A representation of a type in codeModel.
public class	JTypeVar Type variable used to declare generics.
pack-priv class	JTypeWildcard Represents a wildcard type like "?
public class	JVar Variables and fields.
public class	JWhileLoop While statement
pack-priv class	SecureLoader Class defined for safe calls of getClassLoader methods of any kind (context/system/class classloader.
pack-priv class	TypedAnnotationWriter<A extends Annotation, W extends JAnnotationWriter<A>> Dynamically implements the typed annotation writer interfaces.

Package com.sun.codemodel

Library for generating Java source code

Using CodeModel

Performance

Interface Summary

Class Summary