| type signature | Java type |
|---|
* Z | boolean |
* B | byte |
* S | short |
* C | char |
* I | int |
* F | float |
* J | long |
* D | double |
* Ljava/lang/Object; |
* java.lang.Object |
* [[I | int[][] |
* (Ljava/lang/Object;I)V |
* method with argument types Object and
* int and void return type. |
* ()I |
* method without arguments
* and int return type. |
* <E:Ljava/lang/Object;>Ljava/lang/Object;Ljava/util/Collection<TE;>; |
*
|
* generic class over <E extends Object> extending
* Object and implementing Collections<E> |
* <T:Ljava/lang/Object;>([TT;)[TT; |
*
|
* generic method over <T extends Object> taking an
* array of T as parameters and returning an array of T. |
*
*
*
* @author Jochen Hoenicke
*/
public class TypeSignature {
/**
* This is a private method for generating the signature of a
* given type.
*/
private static final StringBuffer appendSignature(StringBuffer sb,
Class javaType) {
if (javaType.isPrimitive()) {
if (javaType == Boolean.TYPE)
return sb.append('Z');
else if (javaType == Byte.TYPE)
return sb.append('B');
else if (javaType == Character.TYPE)
return sb.append('C');
else if (javaType == Short.TYPE)
return sb.append('S');
else if (javaType == Integer.TYPE)
return sb.append('I');
else if (javaType == Long.TYPE)
return sb.append('J');
else if (javaType == Float.TYPE)
return sb.append('F');
else if (javaType == Double.TYPE)
return sb.append('D');
else if (javaType == Void.TYPE)
return sb.append('V');
else
throw new InternalError("Unknown primitive type: "+javaType);
} else if (javaType.isArray()) {
return appendSignature(sb.append('['),
javaType.getComponentType());
} else {
return sb.append('L')
.append(javaType.getName().replace('.','/')).append(';');
}
}
/**
* Generates the type signature of the given Class.
* @param clazz a java.lang.Class, this may also be a primitive or
* array type.
* @return the type signature.
*/
public static String getSignature(Class clazz) {
return appendSignature(new StringBuffer(), clazz).toString();
}
/**
* Generates a method signature.
* @param paramT the java.lang.Class of the parameter types of the method.
* @param returnT the java.lang.Class of the return type of the method.
* @return the method type signature
*/
public static String getSignature(Class paramT[], Class returnT) {
StringBuffer sig = new StringBuffer("(");
for (int i=0; i< paramT.length; i++)
appendSignature(sig, paramT[i]);
return appendSignature(sig.append(')'), returnT).toString();
}
/**
* Generates a Class object for a type signature. This is the
* inverse function of getSignature.
* @param typeSig a single type signature
* @return the Class object representing that type.
*/
public static Class getClass(String typeSig)
throws ClassNotFoundException
{
switch(typeSig.charAt(0)) {
case 'Z':
return Boolean.TYPE;
case 'B':
return Byte.TYPE;
case 'C':
return Character.TYPE;
case 'S':
return Short.TYPE;
case 'I':
return Integer.TYPE;
case 'F':
return Float.TYPE;
case 'J':
return Long.TYPE;
case 'D':
return Double.TYPE;
case 'V':
return Void.TYPE;
case 'L':
typeSig = typeSig.substring(1, typeSig.length()-1)
.replace('/','.');
/* fall through */
case '[':
return Class.forName(typeSig);
}
throw new IllegalArgumentException(typeSig);
}
/**
* Check if the given type is a two slot type. The only two slot
* types are long and double.
*/
private static boolean usingTwoSlots(char type) {
return "JD".indexOf(type) >= 0;
}
/**
* Returns the number of words, an object of the given simple type
* signature takes. For long and double this is two, for all other
* types it is one.
*/
public static int getTypeSize(String typeSig) {
return usingTwoSlots(typeSig.charAt(0)) ? 2 : 1;
}
/**
* Gets the element type of an array.
* @param typeSig type signature of the array.
* @return type signature for the element type.
* @exception IllegalArgumentException if typeSig is not an array
* type signature.
*/
public static String getElementType(String typeSig) {
if (typeSig.charAt(0) != '[')
throw new IllegalArgumentException();
return typeSig.substring(1);
}
/**
* Gets the ClassInfo for a class type.
* @param classpath the classpath in which the ClassInfo is searched.
* @param typeSig type signature of the class.
* @return the ClassInfo object for the class.
* @exception IllegalArgumentException if typeSig is not an class
* type signature.
*/
public static ClassInfo getClassInfo(ClassPath classpath, String typeSig) {
if (typeSig.charAt(0) != 'L')
throw new IllegalArgumentException();
return classpath.getClassInfo
(typeSig.substring(1, typeSig.length()-1).replace('/', '.'));
}
/**
* Skips the next entry of a method type signature
* @param methodTypeSig type signature of the method.
* @param position the index to the last entry.
* @return the index to the next entry.
*/
public static int skipType(String methodTypeSig, int position) {
char c = methodTypeSig.charAt(position++);
while (c == '[')
c = methodTypeSig.charAt(position++);
if (c == 'L' || c == 'T') {
int angledepth = 0;
c = methodTypeSig.charAt(position++);
while (c != ';' || angledepth > 0) {
if (c == '<')
angledepth++;
else if (c == '>')
angledepth--;
c = methodTypeSig.charAt(position++);
}
}
return position;
}
/**
* Gets the number of words the parameters for the given method
* type signature takes. This is the sum of getTypeSize() for
* each parameter type.
* @param methodTypeSig the method type signature.
* @return the number of words the parameters take.
*/
public static int getParameterSize(String methodTypeSig) {
int nargs = 0;
int i = 1;
for (;;) {
char c = methodTypeSig.charAt(i);
if (c == ')')
return nargs;
i = skipType(methodTypeSig, i);
if (usingTwoSlots(c))
nargs += 2;
else
nargs++;
}
}
/**
* Gets the size of the return type of the given method in words.
* This is zero for void return type, two for double or long return
* type and one otherwise.
* @param methodTypeSig the method type signature.
* @return the size of the return type in words.
*/
public static int getReturnSize(String methodTypeSig) {
int length = methodTypeSig.length();
if (methodTypeSig.charAt(length - 2) == ')') {
// This is a single character return type.
char returnType = methodTypeSig.charAt(length - 1);
return returnType == 'V' ? 0
: usingTwoSlots(returnType) ? 2 : 1;
} else
// All multi character return types take one parameter
return 1;
}
/**
* Gets the argument type signatures of the given template signature.
* @param templateTypeSig the template type signature.
* @return an array containing all parameter types in correct order.
*/
public static String[] getArgumentTypes(String templateTypeSig) {
System.err.println(templateTypeSig);
int pos = 1;
int count = 0;
char c;
while ((c = templateTypeSig.charAt(pos)) != '>') {
if (c == '*') {
pos++;
} else {
if (c == '+' || c == '-')
pos++;
pos = skipType(templateTypeSig, pos);
}
count++;
}
String[] params = new String[count];
pos = 1;
for (int i = 0; i < count; i++) {
int start = pos;
c = templateTypeSig.charAt(pos);
if (c == '*') {
pos++;
} else {
if (c == '+' || c == '-')
pos++;
pos = skipType(templateTypeSig, pos);
}
params[i] = templateTypeSig.substring(start, pos);
}
return params;
}
/**
* Gets the parameter type signatures of the given method signature.
* @param methodTypeSig the method type signature.
* @return an array containing all parameter types in correct order.
*/
public static String[] getParameterTypes(String methodTypeSig) {
System.err.println(methodTypeSig);
int pos = 1;
int count = 0;
while (methodTypeSig.charAt(pos) != ')') {
pos = skipType(methodTypeSig, pos);
count++;
}
String[] params = new String[count];
pos = 1;
for (int i = 0; i < count; i++) {
int start = pos;
pos = skipType(methodTypeSig, pos);
params[i] = methodTypeSig.substring(start, pos);
}
return params;
}
/**
* Gets the return type for a method signature
* @param methodTypeSig the method signature.
* @return the return type for a method signature, `V' for void methods.
*/
public static String getReturnType(String methodTypeSig) {
return methodTypeSig.substring(methodTypeSig.lastIndexOf(')')+1);
}
/**
* Gets the names and types of the generic parameters of the given type signature.
* @param typeSig the type signature.
* @return an array containing all generic parameters together with their
* type in correct order, or null if there aren't any generic parameters.
*/
public static String[] getGenericSignatures(String typeSig) {
System.err.println(typeSig);
if (typeSig.charAt(0) != '<')
return null;
int pos = 1;
int count = 0;
while (typeSig.charAt(pos) != '>') {
while (typeSig.charAt(pos) != ':')
pos++;
/* check for empty entry */
if (typeSig.charAt(pos+1) == ':')
pos++;
while (typeSig.charAt(pos) == ':') {
/* skip colon and type */
pos = skipType(typeSig, pos + 1);
}
count++;
}
String[] params = new String[count];
pos = 1;
count = 0;
while (typeSig.charAt(pos) != '>') {
int spos = pos;
while (typeSig.charAt(pos) != ':')
pos++;
/* check for empty entry */
if (typeSig.charAt(pos+1) == ':')
pos++;
while (typeSig.charAt(pos) == ':') {
/* skip colon and type */
pos = skipType(typeSig, pos + 1);
}
params[count++] = typeSig.substring(spos, pos);
}
return params;
}
/**
* Gets the names of the generic parameters of the given type signature.
* @param typeSig the type signature.
* @return an array containing all generic parameter types
* in correct order, or null if there aren't any generic parameters.
*/
public static String[] getGenericNames(String typeSig) {
System.err.println(typeSig);
if (typeSig.charAt(0) != '<')
return null;
int pos = 1;
int count = 0;
while (typeSig.charAt(pos) != '>') {
while (typeSig.charAt(pos) != ':')
pos++;
/* check for empty entry */
if (typeSig.charAt(pos+1) == ':')
pos++;
while (typeSig.charAt(pos) == ':') {
/* skip colon and type */
pos = skipType(typeSig, pos + 1);
}
count++;
}
String[] params = new String[count];
pos = 1;
count = 0;
while (typeSig.charAt(pos) != '>') {
int spos = pos;
while (typeSig.charAt(pos) != ':')
pos++;
params[count++] = typeSig.substring(spos, pos);
/* check for empty entry */
if (typeSig.charAt(pos+1) == ':')
pos++;
while (typeSig.charAt(pos) == ':') {
/* skip colon and type */
pos = skipType(typeSig, pos + 1);
}
}
return params;
}
/**
* Gets the signature of the super class from a class signature.
* @param typeSig the class's signature.
* @return the signature of the super class.
*/
public static String getSuperSignature(String typeSig) {
int pos = 0;
if (typeSig.charAt(0) == '<') {
/* Skip generic info */
pos++;
while (typeSig.charAt(pos) != '>') {
while (typeSig.charAt(pos) != ':')
pos++;
/* check for empty entry */
if (typeSig.charAt(pos+1) == ':')
pos++;
while (typeSig.charAt(pos) == ':') {
/* skip colon and type */
pos = skipType(typeSig, pos + 1);
}
}
pos++;
}
return typeSig.substring(pos, skipType(typeSig, pos));
}
/**
* Gets the signatures of the super interfaces from a class signature.
* @param typeSig the class's signature.
* @return an array containing the signatures of the interfaces.
*/
public static String[] getIfaceSignatures(String typeSig) {
int pos = 0;
if (typeSig.charAt(0) == '<') {
/* Skip generic info */
pos++;
while (typeSig.charAt(pos) != '>') {
while (typeSig.charAt(pos) != ':')
pos++;
/* check for empty entry */
if (typeSig.charAt(pos+1) == ':')
pos++;
while (typeSig.charAt(pos) == ':') {
/* skip colon and type */
pos = skipType(typeSig, pos + 1);
}
}
pos++;
}
pos = skipType(typeSig, pos);
ArrayList list = new ArrayList();
while (pos < typeSig.length()) {
int epos = skipType(typeSig, pos);
list.add(typeSig.substring(pos, epos));
pos = epos;
}
return (String[]) list.toArray(new String[list.size()]);
}
private static int mapGenericsInType(String typeSig, Map generics,
StringBuffer mapped, int spos) {
int pos = spos;
char c = typeSig.charAt(pos++);
while (c == '[')
c = typeSig.charAt(pos++);
if (c == 'T') {
int epos = typeSig.indexOf(';', pos);
String key = typeSig.substring(pos, epos);
String mapval = (String) generics.get(key);
if (mapval != null) {
mapped.append(typeSig.substring(spos, pos - 1))
.append(key);
spos = epos + 1;
}
pos = epos + 1;
} else if (c == 'L') {
c = typeSig.charAt(pos++);
while (c != ';' && c != '<')
c = typeSig.charAt(pos++);
if (c == '<') {
mapped.append(typeSig.substring(spos, pos));
while (typeSig.charAt(pos) != '>') {
pos = mapGenericsInType(typeSig, generics, mapped, pos);
}
spos = pos;
pos += 2;
}
}
mapped.append(typeSig.substring(spos, pos));
return pos;
}
/**
* Map the names of the generic parameters in the given type signature
* and return the type signature with the generic parameters mapped to
* (more or less) real types.
* @param typeSig the type signature.
* @param generics A map from generic names to type signatures.
* @return the mapped generic type signature.
*/
public static String mapGenerics(String typeSig, Map generics) {
StringBuffer mapped = new StringBuffer();
int pos = 0;
int spos = 0;
if (typeSig.length() == 0)
return "";
char c = typeSig.charAt(pos++);
if (c == '<') {
c = typeSig.charAt(pos++);
while (c != '>') {
while (c != ':') {
c = typeSig.charAt(pos++);
}
if (typeSig.charAt(pos) == ':')
pos++;
while (c == ':') {
mapped.append(typeSig.substring(spos, pos));
pos = mapGenericsInType(typeSig, generics, mapped, pos);
spos = pos;
c = typeSig.charAt(pos);
}
}
}
if (c == '(') {
while (typeSig.charAt(pos) != ')') {
mapped.append(typeSig.substring(spos, pos));
pos = mapGenericsInType(typeSig, generics, mapped, pos);
spos = pos;
}
pos++;
}
mapped.append(typeSig.substring(spos, pos));
while (pos < typeSig.length()) {
pos = mapGenericsInType(typeSig, generics, mapped, pos);
}
return mapped.toString();
}
/**
* Gets the default value an object of the given type has. It is
* null for objects and arrays, Integer(0) for boolean and short
* integer types or Long(0L), Double(0.0), Float(0.0F) for long,
* double and float. This seems strange, but this way the type
* returned is the same as for FieldInfo.getConstant().
*
* @param typeSig the type signature.
* @return the default value.
* @exception IllegalArgumentException if this is a method type signature.
*/
public static Object getDefaultValue(String typeSig) {
switch(typeSig.charAt(0)) {
case 'Z':
case 'B':
case 'S':
case 'C':
case 'I':
return new Integer(0);
case 'J':
return new Long(0L);
case 'D':
return new Double(0.0);
case 'F':
return new Float(0.0F);
case 'L':
case '[':
return null;
default:
throw new IllegalArgumentException(typeSig);
}
}
/**
* Checks if there is a valid class name starting at index
* in string typeSig and ending with a semicolon.
* @return the index at which the class name ends.
* @exception IllegalArgumentException if there was an illegal character.
* @exception StringIndexOutOfBoundsException if the typeSig ended early.
*/
private static int checkClassName(String clName, int i)
throws IllegalArgumentException, StringIndexOutOfBoundsException
{
char c = clName.charAt(i++);
while (c != ';' && c != '.' && c != '<') {
if (c != '/' && !Character.isJavaIdentifierPart(c))
throw new IllegalArgumentException("Illegal java class name: "
+ clName);
c = clName.charAt(i++);
}
if (c == '<') {
c = clName.charAt(i++);
do {
if (c == '*')
i++;
else {
if (c == '+' || c == '-')
c = clName.charAt(i++);
if (c != 'L' && c != 'T' && c != '[')
throw new IllegalArgumentException
("Wrong class instantiation: "+clName);
i = checkTypeSig(clName, i - 1);
}
c = clName.charAt(i++);
} while (c != '>');
c = clName.charAt(i++);
}
if (c == '.')
return checkClassName(clName, i);
if (c != ';')
throw new IllegalArgumentException
("no ; after > in "+clName);
return i;
}
/**
* Checks if there is a valid class name starting at index
* in string typeSig and ending with a semicolon.
* @return the index at which the class name ends.
* @exception IllegalArgumentException if there was an illegal character.
* @exception StringIndexOutOfBoundsException if the typeSig ended early.
*/
private static int checkTemplateName(String clName, int i)
throws IllegalArgumentException, StringIndexOutOfBoundsException
{
while (true) {
char c = clName.charAt(i++);
if (c == ';')
return i;
if (!Character.isJavaIdentifierPart(c))
throw new IllegalArgumentException("Illegal java class name: "
+ clName);
}
}
/**
* Checks if there is a valid simple type signature starting at index
* in string typeSig.
* @return the index at which the type signature ends.
* @exception IllegalArgumentException if there was an illegal character.
* @exception StringIndexOutOfBoundsException if the typeSig ended early.
*/
private static int checkTypeSig(String typeSig, int index) {
char c = typeSig.charAt(index++);
while (c == '[')
c = typeSig.charAt(index++);
if (c == 'L') {
index = checkClassName(typeSig, index);
} else if (c == 'T') {
index = checkTemplateName(typeSig, index);
} else {
if ("ZBSCIJFD".indexOf(c) == -1)
throw new IllegalArgumentException("Type sig error: "+typeSig);
}
return index;
}
/**
* Checks whether a given type signature starts with valid generic
* part and returns the index where generics end.
* @param typeSig the type signature.
* @param i the start index.
* @exception NullPointerException if typeSig is null.
* @exception IllegalArgumentException if typeSig is not a valid
* type signature.
* @return 0 if no generics at beginning, otherwise the
* index after the > sign.
*/
private static int checkGenerics(String typeSig, int i) {
if (typeSig.charAt(i) == '<') {
i++;
char c = typeSig.charAt(i++);
if (c == '>')
throw new IllegalArgumentException("Empty Generics: "+typeSig);
while (c != '>') {
if (c == ':')
throw new IllegalArgumentException("Empty type name: "+typeSig);
while (c != ':') {
if (!Character.isJavaIdentifierPart(c))
throw new IllegalArgumentException
("Illegal generic name: "+ typeSig);
c = typeSig.charAt(i++);
}
c = typeSig.charAt(i++);
if (c != 'L' && c != 'T' && c != ':')
throw new IllegalArgumentException
("Wrong generic extends: "+typeSig);
if (c != ':')
i = checkTypeSig(typeSig, i - 1);
c = typeSig.charAt(i++);
while(c == ':') {
i = checkTypeSig(typeSig, i);
c = typeSig.charAt(i++);
}
}
}
return i;
}
/**
* Checks whether a given type signature is a valid (not method)
* type signature. Throws an exception otherwise.
* @param typeSig the type signature.
* @exception NullPointerException if typeSig is null.
* @exception IllegalArgumentException if typeSig is not a valid
* type signature or if it's a method type signature.
*/
public static void checkTypeSig(String typeSig)
throws IllegalArgumentException
{
try {
int i = checkGenerics(typeSig, 0);
if (checkTypeSig(typeSig, i) != typeSig.length())
throw new IllegalArgumentException
("Type sig too long: "+typeSig);
} catch (StringIndexOutOfBoundsException ex) {
throw new IllegalArgumentException
("Incomplete type sig: "+typeSig);
}
}
/**
* Checks whether a given type signature is a valid class
* type signature. Throws an exception otherwise.
* A class type signature starts optionally with generics,
* followed by type signature of super class, followed by
* type signature of super interfaces.
* @param typeSig the type signature.
* @exception NullPointerException if typeSig is null.
* @exception IllegalArgumentException if typeSig is not a valid
* type signature or if it's a method type signature.
*/
public static void checkClassTypeSig(String typeSig)
throws IllegalArgumentException
{
try {
int i = checkGenerics(typeSig, 0);
i = checkTypeSig(typeSig, i);
while (i != typeSig.length()) {
i = checkTypeSig(typeSig, i);
}
} catch (StringIndexOutOfBoundsException ex) {
throw new IllegalArgumentException
("Incomplete type sig: "+typeSig);
}
}
/**
* Checks whether a given type signature is a valid method
* type signature. Throws an exception otherwise.
* @param typeSig the type signature.
* @exception NullPointerException if typeSig is null.
* @exception IllegalArgumentException if typeSig is not a valid
* method type signature.
*/
public static void checkMethodTypeSig(String typeSig)
throws IllegalArgumentException
{
try {
int i = checkGenerics(typeSig, 0);
if (typeSig.charAt(i) != '(')
throw new IllegalArgumentException
("No method signature: "+typeSig);
i++;
while (typeSig.charAt(i) != ')')
i = checkTypeSig(typeSig, i);
// skip closing parenthesis.
i++;
if (typeSig.charAt(i) == 'V')
// accept void return type.
i++;
else
i = checkTypeSig(typeSig, i);
if (i != typeSig.length())
throw new IllegalArgumentException
("Type sig too long: "+typeSig);
} catch (StringIndexOutOfBoundsException ex) {
throw new IllegalArgumentException
("Incomplete type sig: "+typeSig);
}
}
}