CtField object.
* The created field must be added to a class
* with CtClass.addField().
* An initial value of the field is specified
* by a CtField.Initializer object.
*
* If getter and setter methods are needed,
* call CtNewMethod.getter() and
* CtNewMethod.setter().
*
* @param type field type
* @param name field name
* @param declaring the class to which the field will be added.
*
* @see CtClass#addField(CtField)
* @see CtNewMethod#getter(String,CtField)
* @see CtNewMethod#setter(String,CtField)
* @see CtField.Initializer
*/
public CtField(CtClass type, String name, CtClass declaring)
throws CannotCompileException
{
this(Descriptor.of(type), name, declaring);
}
/**
* Creates a copy of the given field.
* The created field must be added to a class
* with CtClass.addField().
* An initial value of the field is specified
* by a CtField.Initializer object.
*
*
If getter and setter methods are needed,
* call CtNewMethod.getter() and
* CtNewMethod.setter().
*
* @param src the original field
* @param declaring the class to which the field will be added.
* @see CtNewMethod#getter(String,CtField)
* @see CtNewMethod#setter(String,CtField)
* @see CtField.Initializer
*/
public CtField(CtField src, CtClass declaring)
throws CannotCompileException
{
this(src.fieldInfo.getDescriptor(), src.fieldInfo.getName(),
declaring);
}
private CtField(String typeDesc, String name, CtClass clazz)
throws CannotCompileException
{
super(clazz);
next = null;
ClassFile cf = clazz.getClassFile2();
if (cf == null)
throw new CannotCompileException("bad declaring class: "
+ clazz.getName());
fieldInfo = new FieldInfo(cf.getConstPool(), name, typeDesc);
}
CtField(FieldInfo fi, CtClass clazz) {
super(clazz);
fieldInfo = fi;
next = null;
}
/* Javac.CtFieldWithInit overrides.
*/
protected ASTree getInitAST() { return null; }
/* Called by CtClassType.addField().
*/
Initializer getInit() {
ASTree tree = getInitAST();
if (tree == null)
return null;
else
return Initializer.byExpr(tree);
}
/**
* Compiles the given source code and creates a field.
* Examples of the source code are:
*
*
* "public String name;"
* "public int k = 3;"
*
* Note that the source code ends with ';'
* (semicolon).
*
* @param src the source text.
* @param declaring the class to which the created field is added.
*/
public static CtField make(String src, CtClass declaring)
throws CannotCompileException
{
Javac compiler = new Javac(declaring);
try {
CtMember obj = compiler.compile(src);
if (obj instanceof CtField)
return (CtField)obj; // an instance of Javac.CtFieldWithInit
}
catch (CompileError e) {
throw new CannotCompileException(e);
}
throw new CannotCompileException("not a field");
}
static CtField append(CtField list, CtField tail) {
tail.next = null;
if (list == null)
return tail;
else {
CtField lst = list;
while (lst.next != null)
lst = lst.next;
lst.next = tail;
return list;
}
}
static int count(CtField f) {
int n = 0;
while (f != null) {
++n;
f = f.next;
}
return n;
}
/**
* Returns the FieldInfo representing the field in the class file.
*/
public FieldInfo getFieldInfo() {
declaringClass.checkModify();
return fieldInfo;
}
/**
* Undocumented method. Do not use; internal-use only.
*/
public FieldInfo getFieldInfo2() { return fieldInfo; }
/**
* Returns the class declaring the field.
*/
public CtClass getDeclaringClass() {
// this is redundant but for javadoc.
return super.getDeclaringClass();
}
/**
* Returns the name of the field.
*/
public String getName() {
return fieldInfo.getName();
}
/**
* Changes the name of the field.
*/
public void setName(String newName) {
fieldInfo.setName(newName);
}
/**
* Returns the encoded modifiers of the field.
*
* @see Modifier
*/
public int getModifiers() {
return AccessFlag.toModifier(fieldInfo.getAccessFlags());
}
/**
* Sets the encoded modifiers of the field.
*
* @see Modifier
*/
public void setModifiers(int mod) {
fieldInfo.setAccessFlags(AccessFlag.of(mod));
}
/**
* Returns the type of the field.
*/
public CtClass getType() throws NotFoundException {
return Descriptor.toCtClass(fieldInfo.getDescriptor(),
declaringClass.getClassPool());
}
/**
* Sets the type of the field.
*/
public void setType(CtClass clazz) {
declaringClass.checkModify();
fieldInfo.setDescriptor(Descriptor.of(clazz));
}
/**
* Obtains an attribute with the given name.
* If that attribute is not found in the class file, this
* method returns null.
*
* @param name attribute name
*/
public byte[] getAttribute(String name) {
AttributeInfo ai = fieldInfo.getAttribute(name);
if (ai == null)
return null;
else
return ai.get();
}
/**
* Adds an attribute. The attribute is saved in the class file.
*
* @param name attribute name
* @param data attribute value
*/
public void setAttribute(String name, byte[] data) {
declaringClass.checkModify();
fieldInfo.addAttribute(new AttributeInfo(fieldInfo.getConstPool(),
name, data));
}
// inner classes
/**
* Instances of this class specify how to initialize a field.
* Initializer is passed to
* CtClass.addField() with a CtField.
*
*
This class cannot be instantiated with the new operator.
* Factory methods such as byParameter() and
* byNew
* must be used for the instantiation. They create a new instance with
* the given parameters and return it.
*
* @see CtClass#addField(CtField,CtField.Initializer)
*/
public static abstract class Initializer {
/**
* Makes an initializer that assigns a constant integer value.
* The field must be integer type.
*/
public static Initializer constant(int i) {
return new IntInitializer(i);
}
/**
* Makes an initializer that assigns a constant long value.
* The field must be long type.
*/
public static Initializer constant(long l) {
return new LongInitializer(l);
}
/**
* Makes an initializer that assigns a constant double value.
* The field must be double type.
*/
public static Initializer constant(double d) {
return new DoubleInitializer(d);
}
/**
* Makes an initializer that assigns a constant string value.
* The field must be java.lang.String type.
*/
public static Initializer constant(String s) {
return new StringInitializer(s);
}
/**
* Makes an initializer using a constructor parameter.
*
*
The initial value is the * N-th parameter given to the constructor of the object including * the field. If the constructor takes less than N parameters, * the field is not initialized. * If the field is static, it is never initialized. * * @param nth the n-th (>= 0) parameter is used as * the initial value. * If nth is 0, then the first parameter is * used. */ public static Initializer byParameter(int nth) { ParamInitializer i = new ParamInitializer(); i.nthParam = nth; return i; } /** * Makes an initializer creating a new object. * *
This initializer creates a new object and uses it as the initial * value of the field. The constructor of the created object receives * the parameter: * *
Object obj - the object including the field.If the initialized field is static, then the constructor does * not receive any parameters. * * @param objectType the class instantiated for the initial value. */ public static Initializer byNew(CtClass objectType) { NewInitializer i = new NewInitializer(); i.objectType = objectType; i.stringParams = null; i.withConstructorParams = false; return i; } /** * Makes an initializer creating a new object. * *
This initializer creates a new object and uses it as the initial * value of the field. The constructor of the created object receives * the parameters: * *
Object obj - the object including the field.String[] strs - the character strings specified
* by stringParamsIf the initialized field is static, then the constructor
* receives only strs.
*
* @param objectType the class instantiated for the initial value.
* @param stringParams the array of strings passed to the
* constructor.
*/
public static Initializer byNew(CtClass objectType,
String[] stringParams) {
NewInitializer i = new NewInitializer();
i.objectType = objectType;
i.stringParams = stringParams;
i.withConstructorParams = false;
return i;
}
/**
* Makes an initializer creating a new object.
*
*
This initializer creates a new object and uses it as the initial * value of the field. The constructor of the created object receives * the parameters: * *
Object obj - the object including the field.Object[] args - the parameters passed to the
* constructor of the object including the
* filed.
* If the initialized field is static, then the constructor does * not receive any parameters. * * @param objectType the class instantiated for the initial value. * * @see javassist.CtField.Initializer#byNewArray(CtClass,int) * @see javassist.CtField.Initializer#byNewArray(CtClass,int[]) */ public static Initializer byNewWithParams(CtClass objectType) { NewInitializer i = new NewInitializer(); i.objectType = objectType; i.stringParams = null; i.withConstructorParams = true; return i; } /** * Makes an initializer creating a new object. * *
This initializer creates a new object and uses it as the initial * value of the field. The constructor of the created object receives * the parameters: * *
Object obj - the object including the field.String[] strs - the character strings specified
* by stringParamsObject[] args - the parameters passed to the
* constructor of the object including the
* filed.
* If the initialized field is static, then the constructor receives
* only strs.
*
* @param objectType the class instantiated for the initial value.
* @param stringParams the array of strings passed to the
* constructor.
*/
public static Initializer byNewWithParams(CtClass objectType,
String[] stringParams) {
NewInitializer i = new NewInitializer();
i.objectType = objectType;
i.stringParams = stringParams;
i.withConstructorParams = true;
return i;
}
/**
* Makes an initializer calling a static method.
*
*
This initializer calls a static method and uses the returned * value as the initial value of the field. * The called method receives the parameters: * *
Object obj - the object including the field.If the initialized field is static, then the method does * not receive any parameters. * *
The type of the returned value must be the same as the field * type. * * @param methodClass the class that the static method is * declared in. * @param methodName the name of the satic method. */ public static Initializer byCall(CtClass methodClass, String methodName) { MethodInitializer i = new MethodInitializer(); i.objectType = methodClass; i.methodName = methodName; i.stringParams = null; i.withConstructorParams = false; return i; } /** * Makes an initializer calling a static method. * *
This initializer calls a static method and uses the returned * value as the initial value of the field. The called method * receives the parameters: * *
Object obj - the object including the field.String[] strs - the character strings specified
* by stringParamsIf the initialized field is static, then the method
* receive only strs.
*
*
The type of the returned value must be the same as the field * type. * * @param methodClass the class that the static method is * declared in. * @param methodName the name of the satic method. * @param stringParams the array of strings passed to the * static method. */ public static Initializer byCall(CtClass methodClass, String methodName, String[] stringParams) { MethodInitializer i = new MethodInitializer(); i.objectType = methodClass; i.methodName = methodName; i.stringParams = stringParams; i.withConstructorParams = false; return i; } /** * Makes an initializer calling a static method. * *
This initializer calls a static method and uses the returned * value as the initial value of the field. The called method * receives the parameters: * *
Object obj - the object including the field.Object[] args - the parameters passed to the
* constructor of the object including the
* filed.
* If the initialized field is static, then the method does * not receive any parameters. * *
The type of the returned value must be the same as the field * type. * * @param methodClass the class that the static method is * declared in. * @param methodName the name of the satic method. */ public static Initializer byCallWithParams(CtClass methodClass, String methodName) { MethodInitializer i = new MethodInitializer(); i.objectType = methodClass; i.methodName = methodName; i.stringParams = null; i.withConstructorParams = true; return i; } /** * Makes an initializer calling a static method. * *
This initializer calls a static method and uses the returned * value as the initial value of the field. The called method * receives the parameters: * *
Object obj - the object including the field.String[] strs - the character strings specified
* by stringParamsObject[] args - the parameters passed to the
* constructor of the object including the
* filed.
* If the initialized field is static, then the method
* receive only strs.
*
*
The type of the returned value must be the same as the field
* type.
*
* @param methodClass the class that the static method is
* declared in.
* @param methodName the name of the satic method.
* @param stringParams the array of strings passed to the
* static method.
*/
public static Initializer byCallWithParams(CtClass methodClass,
String methodName, String[] stringParams) {
MethodInitializer i = new MethodInitializer();
i.objectType = methodClass;
i.methodName = methodName;
i.stringParams = stringParams;
i.withConstructorParams = true;
return i;
}
/**
* Makes an initializer creating a new array.
*
* @param type the type of the array.
* @param size the size of the array.
* @throws NotFoundException if the type of the array components
* is not found.
*/
public static Initializer byNewArray(CtClass type, int size)
throws NotFoundException
{
return new ArrayInitializer(type.getComponentType(), size);
}
/**
* Makes an initializer creating a new multi-dimensional array.
*
* @param type the type of the array.
* @param sizes an int array of the size in every
* dimension.
* The first element is the size in the first
* dimension. The second is in the second, etc.
*/
public static Initializer byNewArray(CtClass type, int[] sizes) {
return new MultiArrayInitializer(type, sizes);
}
/**
* Makes an initializer.
*
* @param source initializer expression.
*/
public static Initializer byExpr(String source) {
return new CodeInitializer(source);
}
static Initializer byExpr(ASTree source) {
return new PtreeInitializer(source);
}
// Check whether this initializer is valid for the field type.
// If it is invaild, this method throws an exception.
void check(CtClass type) throws CannotCompileException {}
// produce codes for initialization
abstract int compile(CtClass type, String name, Bytecode code,
CtClass[] parameters, Javac drv)
throws CannotCompileException;
// produce codes for initialization
abstract int compileIfStatic(CtClass type, String name,
Bytecode code, Javac drv) throws CannotCompileException;
}
static abstract class CodeInitializer0 extends Initializer {
abstract void compileExpr(Javac drv) throws CompileError;
int compile(CtClass type, String name, Bytecode code,
CtClass[] parameters, Javac drv)
throws CannotCompileException
{
try {
code.addAload(0);
compileExpr(drv);
code.addPutfield(Bytecode.THIS, name, Descriptor.of(type));
return code.getMaxStack();
}
catch (CompileError e) {
throw new CannotCompileException(e);
}
}
int compileIfStatic(CtClass type, String name, Bytecode code,
Javac drv) throws CannotCompileException
{
try {
compileExpr(drv);
code.addPutstatic(Bytecode.THIS, name, Descriptor.of(type));
return code.getMaxStack();
}
catch (CompileError e) {
throw new CannotCompileException(e);
}
}
}
static class CodeInitializer extends CodeInitializer0 {
private String expression;
CodeInitializer(String expr) { expression = expr; }
void compileExpr(Javac drv) throws CompileError {
drv.compileExpr(expression);
}
}
static class PtreeInitializer extends CodeInitializer0 {
private ASTree expression;
PtreeInitializer(ASTree expr) { expression = expr; }
void compileExpr(Javac drv) throws CompileError {
drv.compileExpr(expression);
}
}
/**
* A field initialized with a parameter passed to the constructor
* of the class containing that field.
*/
static class ParamInitializer extends Initializer {
int nthParam;
ParamInitializer() {}
int compile(CtClass type, String name, Bytecode code,
CtClass[] parameters, Javac drv)
throws CannotCompileException
{
if (parameters != null && nthParam < parameters.length) {
code.addAload(0);
int nth = nthParamToLocal(nthParam, parameters, false);
int s = code.addLoad(nth, type) + 1;
code.addPutfield(Bytecode.THIS, name, Descriptor.of(type));
return s; // stack size
}
else
return 0; // do not initialize
}
/**
* Computes the index of the local variable that the n-th parameter
* is assigned to.
*
* @param nth n-th parameter
* @param params list of parameter types
* @param isStatic true if the method is static.
*/
static int nthParamToLocal(int nth, CtClass[] params,
boolean isStatic) {
CtClass longType = CtClass.longType;
CtClass doubleType = CtClass.doubleType;
int k;
if (isStatic)
k = 0;
else
k = 1; // 0 is THIS.
for (int i = 0; i < nth; ++i) {
CtClass type = params[i];
if (type == longType || type == doubleType)
k += 2;
else
++k;
}
return k;
}
int compileIfStatic(CtClass type, String name, Bytecode code,
Javac drv) throws CannotCompileException
{
return 0;
}
}
/**
* A field initialized with an object created by the new operator.
*/
static class NewInitializer extends Initializer {
CtClass objectType;
String[] stringParams;
boolean withConstructorParams;
NewInitializer() {}
/**
* Produces codes in which a new object is created and assigned to
* the field as the initial value.
*/
int compile(CtClass type, String name, Bytecode code,
CtClass[] parameters, Javac drv)
throws CannotCompileException
{
int stacksize;
code.addAload(0);
code.addNew(objectType);
code.add(Bytecode.DUP);
code.addAload(0);
if (stringParams == null)
stacksize = 4;
else
stacksize = compileStringParameter(code) + 4;
if (withConstructorParams)
stacksize += CtNewWrappedMethod.compileParameterList(code,
parameters, 1);
code.addInvokespecial(objectType, "