xapi.bytecode.ClassPool Maven / Gradle / Ivy
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/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later,
* or the Apache License Version 2.0.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* MODIFIED BY James Nelson of We The Internet, 2013.
* Repackaged to avoid conflicts with different versions of Javassist,
* and modified Javassist APIs to make them more accessible to outside code.
*/
package xapi.bytecode;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
public class ClassPool {
/**
* Determines the search order.
*
* If this field is true, get() first searches the
* class path associated to this ClassPool and then
* the class path associated with the parent ClassPool.
* Otherwise, the class path associated with the parent is searched
* first.
*
*
The default value is false.
*/
public boolean childFirstLookup = false;
/**
* Turning the automatic pruning on/off.
*
*
If this field is true, CtClass objects are
* automatically pruned by default when toBytecode() etc.
* are called. The automatic pruning can be turned on/off individually
* for each CtClass object.
*
*
The initial value is false.
*
* @see CtClass#prune()
* @see CtClass#stopPruning(boolean)
* @see CtClass#detach()
*/
public static boolean doPruning = false;
private int compressCount;
private static final int COMPRESS_THRESHOLD = 100;
/* releaseUnmodifiedClassFile was introduced for avoiding a bug
of JBoss AOP. So the value should be true except for JBoss AOP.
*/
/**
* If true, unmodified and not-recently-used class files are
* periodically released for saving memory.
*
*
The initial value is true.
*/
public static boolean releaseUnmodifiedClassFile = true;
protected ClassPoolTail source;
protected ClassPool parent;
protected Hashtable classes; // should be synchronous
private static final int INIT_HASH_SIZE = 191;
private ArrayList importedPackages;
/**
* Creates a root class pool. No parent class pool is specified.
*/
public ClassPool() {
this(null);
}
/**
* Creates a root class pool. If useDefaultPath is
* true, appendSystemPath() is called. Otherwise,
* this constructor is equivalent to the constructor taking no
* parameter.
*
* @param useDefaultPath true if the system search path is
* appended.
*/
public ClassPool(boolean useDefaultPath) {
this(null);
if (useDefaultPath) {
appendSystemPath();
}
}
/**
* Creates a class pool.
*
* @param parent the parent of this class pool. If this is a root
* class pool, this parameter must be null.
* @see javassist.ClassPool#getDefault()
*/
public ClassPool(ClassPool parent) {
this.classes = new Hashtable(INIT_HASH_SIZE);
this.source = new ClassPoolTail();
this.parent = parent;
if (parent == null) {
CtClass[] pt = CtClass.primitiveTypes;
for (int i = 0; i < pt.length; ++i) {
classes.put(pt[i].getName(), pt[i]);
}
}
this.compressCount = 0;
clearImportedPackages();
}
/**
* Returns the default class pool.
* The returned object is always identical since this method is
* a singleton factory.
*
* The default class pool searches the system search path,
* which usually includes the platform library, extension
* libraries, and the search path specified by the
* -classpath option or the CLASSPATH
* environment variable.
*
*
When this method is called for the first time, the default
* class pool is created with the following code snippet:
*
*
ClassPool cp = new ClassPool();
* cp.appendSystemPath();
*
*
* If the default class pool cannot find any class files,
* try ClassClassPath and LoaderClassPath.
*
* @see ClassClassPath
* @see LoaderClassPath
*/
public static synchronized ClassPool getDefault() {
if (defaultPool == null) {
defaultPool = new ClassPool(null);
defaultPool.appendSystemPath();
}
return defaultPool;
}
private static ClassPool defaultPool = null;
/**
* Provide a hook so that subclasses can do their own
* caching of classes.
*
* @see #cacheCtClass(String,CtClass,boolean)
* @see #removeCached(String)
*/
protected CtClass getCached(String classname) {
return (CtClass)classes.get(classname);
}
/**
* Provides a hook so that subclasses can do their own
* caching of classes.
*
* @see #getCached(String)
* @see #removeCached(String,CtClass)
*/
protected void cacheCtClass(String classname, CtClass c, boolean dynamic) {
classes.put(classname, c);
}
/**
* Provide a hook so that subclasses can do their own
* caching of classes.
*
* @see #getCached(String)
* @see #cacheCtClass(String,CtClass,boolean)
*/
protected CtClass removeCached(String classname) {
return (CtClass)classes.remove(classname);
}
/**
* Returns the class search path.
*/
@Override
public String toString() {
return source.toString();
}
/**
* This method is periodically invoked so that memory
* footprint will be minimized.
*/
void compress() {
if (compressCount++ > COMPRESS_THRESHOLD) {
compressCount = 0;
Enumeration e = classes.elements();
while (e.hasMoreElements()) {
((CtClass)e.nextElement()).compress();
}
}
}
/**
* Record a package name so that the Javassist compiler searches
* the package to resolve a class name.
* Don't record the java.lang package, which has
* been implicitly recorded by default.
*
* Note that get() in ClassPool does
* not search the recorded package. Only the compiler searches it.
*
* @param packageName the package name.
* It must not include the last '.' (dot).
* For example, "java.util" is valid but "java.util." is wrong.
* @since 3.1
*/
public void importPackage(String packageName) {
importedPackages.add(packageName);
}
/**
* Clear all the package names recorded by importPackage().
* The java.lang package is not removed.
*
* @see #importPackage(String)
* @since 3.1
*/
public void clearImportedPackages() {
importedPackages = new ArrayList();
importedPackages.add("java.lang");
}
/**
* Returns all the package names recorded by importPackage().
*
* @see #importPackage(String)
* @since 3.1
*/
public Iterator getImportedPackages() {
return importedPackages.iterator();
}
/**
* Records a name that never exists.
* For example, a package name can be recorded by this method.
* This would improve execution performance
* since get() does not search the class path at all
* if the given name is an invalid name recorded by this method.
* Note that searching the class path takes relatively long time.
*
* @param name a class name (separeted by dot).
*/
public void recordInvalidClassName(String name) {
source.recordInvalidClassName(name);
}
/**
* Reads a class file and constructs a CtClass
* object with a new name.
* This method is useful if you want to generate a new class as a copy
* of another class (except the class name). For example,
*
*
* getAndRename("Point", "Pair")
*
*
* returns a CtClass object representing Pair
* class. The definition of Pair is the same as that of
* Point class except the class name since Pair
* is defined by reading Point.class.
*
* @param orgName the original (fully-qualified) class name
* @param newName the new class name
*/
public CtClass getAndRename(String orgName, String newName)
throws NotFoundException
{
CtClass clazz = get0(orgName, false);
if (clazz == null) {
throw new NotFoundException(orgName);
}
if (clazz instanceof CtClassType) {
((CtClassType)clazz).setClassPool(this);
}
clazz.setName(newName); // indirectly calls
// classNameChanged() in this class
return clazz;
}
/*
* This method is invoked by CtClassType.setName(). It removes a
* CtClass object from the hash table and inserts it with the new
* name. Don't delegate to the parent.
*/
synchronized void classNameChanged(String oldname, CtClass clazz) {
CtClass c = (CtClass)getCached(oldname);
if (c == clazz)
{
removeCached(oldname); // see getAndRename().
}
String newName = clazz.getName();
checkNotFrozen(newName);
cacheCtClass(newName, clazz, false);
}
/**
* Reads a class file from the source and returns a reference
* to the CtClass
* object representing that class file. If that class file has been
* already read, this method returns a reference to the
* CtClass created when that class file was read at the
* first time.
*
* If classname ends with "[]", then this method
* returns a CtClass object for that array type.
*
*
To obtain an inner class, use "$" instead of "." for separating
* the enclosing class name and the inner class name.
*
* @param classname a fully-qualified class name.
*/
public CtClass get(String classname) throws NotFoundException {
CtClass clazz;
if (classname == null) {
clazz = null;
} else {
clazz = get0(classname, true);
}
if (clazz == null) {
throw new NotFoundException(classname);
} else {
clazz.incGetCounter();
return clazz;
}
}
/**
* Reads a class file from the source and returns a reference
* to the CtClass
* object representing that class file.
* This method is equivalent to get except
* that it returns null when a class file is
* not found and it never throws an exception.
*
* @param classname a fully-qualified class name.
* @return a CtClass object or null.
* @see #get(String)
* @see #find(String)
* @since 3.13
*/
public CtClass getOrNull(String classname) {
CtClass clazz = null;
if (classname == null) {
clazz = null;
} else {
try {
/* ClassPool.get0() never throws an exception
but its subclass may implement get0 that
may throw an exception.
*/
clazz = get0(classname, true);
}
catch (NotFoundException e){}
}
if (clazz != null) {
clazz.incGetCounter();
}
return clazz;
}
/**
* Returns a CtClass object with the given name.
* This is almost equivalent to get(String) except
* that classname can be an array-type "descriptor" (an encoded
* type name) such as [Ljava/lang/Object;.
*
*
Using this method is not recommended; this method should be
* used only to obtain the CtClass object
* with a name returned from getClassInfo in
* javassist.bytecode.ClassPool. getClassInfo
* returns a fully-qualified class name but, if the class is an array
* type, it returns a descriptor.
*
* @param classname a fully-qualified class name or a descriptor
* representing an array type.
* @see #get(String)
* @see xapi.bytecode.ConstPool#getClassInfo(int)
* @see javassist.bytecode.Descriptor#toCtClass(String, ClassPool)
* @since 3.8.1
*/
public CtClass getCtClass(String classname) throws NotFoundException {
if (classname.charAt(0) == '[') {
return Descriptor.toCtClass(classname, this);
} else {
return get(classname);
}
}
/**
* @param useCache false if the cached CtClass must be ignored.
* @param searchParent false if the parent class pool is not searched.
* @return null if the class could not be found.
*/
protected synchronized CtClass get0(String classname, boolean useCache)
throws NotFoundException
{
CtClass clazz = null;
if (useCache) {
clazz = getCached(classname);
if (clazz != null) {
return clazz;
}
}
if (!childFirstLookup && parent != null) {
clazz = parent.get0(classname, useCache);
if (clazz != null) {
return clazz;
}
}
clazz = createCtClass(classname, useCache);
if (clazz != null) {
// clazz.getName() != classname if classname is "[L;".
if (useCache) {
cacheCtClass(clazz.getName(), clazz, false);
}
return clazz;
}
if (childFirstLookup && parent != null) {
clazz = parent.get0(classname, useCache);
}
return clazz;
}
/**
* Creates a CtClass object representing the specified class.
* It first examines whether or not the corresponding class
* file exists. If yes, it creates a CtClass object.
*
* @return null if the class file could not be found.
*/
protected CtClass createCtClass(String classname, boolean useCache) {
// accept "[L;" as a class name.
if (classname.charAt(0) == '[') {
classname = Descriptor.toClassName(classname);
}
if (classname.endsWith("[]")) {
String base = classname.substring(0, classname.indexOf('['));
if ((!useCache || getCached(base) == null) && find(base) == null) {
return null;
} else {
return new CtArray(classname, this);
}
}
else
if (find(classname) == null) {
return null;
} else {
return new CtClassType(classname, this);
}
}
/**
* Searches the class path to obtain the URL of the class file
* specified by classname. It is also used to determine whether
* the class file exists.
*
* @param classname a fully-qualified class name.
* @return null if the class file could not be found.
* @see CtClass#getURL()
*/
public URL find(String classname) {
return source.find(classname);
}
/*
* Is invoked by CtClassType.setName() and methods in this class.
* This method throws an exception if the class is already frozen or
* if this class pool cannot edit the class since it is in a parent
* class pool.
*
* @see checkNotExists(String)
*/
void checkNotFrozen(String classname) throws RuntimeException {
CtClass clazz = getCached(classname);
if (clazz == null) {
if (!childFirstLookup && parent != null) {
try {
clazz = parent.get0(classname, true);
}
catch (NotFoundException e) {}
if (clazz != null) {
throw new RuntimeException(classname
+ " is in a parent ClassPool. Use the parent.");
}
}
}
else
if (clazz.isFrozen()) {
throw new RuntimeException(classname
+ ": frozen class (cannot edit)");
}
}
/*
* This method returns null if this or its parent class pool does
* not contain a CtClass object with the class name.
*
* @see checkNotFrozen(String)
*/
CtClass checkNotExists(String classname) {
CtClass clazz = getCached(classname);
if (clazz == null) {
if (!childFirstLookup && parent != null) {
try {
clazz = parent.get0(classname, true);
}
catch (NotFoundException e) {}
}
}
return clazz;
}
/* for CtClassType.getClassFile2(). Don't delegate to the parent.
*/
InputStream openClassfile(String classname) throws NotFoundException {
return source.openClassfile(classname);
}
void writeClassfile(String classname, OutputStream out)
throws NotFoundException, IOException
{
source.writeClassfile(classname, out);
}
/**
* Reads class files from the source and returns an array of
* CtClass
* objects representing those class files.
*
* If an element of classnames ends with "[]",
* then this method
* returns a CtClass object for that array type.
*
* @param classnames an array of fully-qualified class name.
*/
public CtClass[] get(String[] classnames) throws NotFoundException {
if (classnames == null) {
return new CtClass[0];
}
int num = classnames.length;
CtClass[] result = new CtClass[num];
for (int i = 0; i < num; ++i) {
result[i] = get(classnames[i]);
}
return result;
}
/**
* Creates a new class (or interface) from the given class file.
* If there already exists a class with the same name, the new class
* overwrites that previous class.
*
*
This method is used for creating a CtClass object
* directly from a class file. The qualified class name is obtained
* from the class file; you do not have to explicitly give the name.
*
* @param classfile class file.
* @throws RuntimeException if there is a frozen class with the
* the same name.
* @see #makeClassIfNew(InputStream)
* @see javassist.ByteArrayClassPath
*/
public CtClass makeClass(InputStream classfile)
throws IOException, RuntimeException
{
return makeClass(classfile, true);
}
/**
* Creates a new class (or interface) from the given class file.
* If there already exists a class with the same name, the new class
* overwrites that previous class.
*
*
This method is used for creating a CtClass object
* directly from a class file. The qualified class name is obtained
* from the class file; you do not have to explicitly give the name.
*
* @param classfile class file.
* @param ifNotFrozen throws a RuntimeException if this parameter is true
* and there is a frozen class with the same name.
* @see javassist.ByteArrayClassPath
*/
public CtClass makeClass(InputStream classfile, boolean ifNotFrozen)
throws IOException, RuntimeException
{
compress();
classfile = new BufferedInputStream(classfile);
CtClass clazz = new CtClassType(classfile, this);
clazz.checkModify();
String classname = clazz.getName();
if (ifNotFrozen) {
checkNotFrozen(classname);
}
cacheCtClass(classname, clazz, true);
return clazz;
}
/**
* Creates a new class (or interface) from the given class file.
* If there already exists a class with the same name, this method
* returns the existing class; a new class is never created from
* the given class file.
*
*
This method is used for creating a CtClass object
* directly from a class file. The qualified class name is obtained
* from the class file; you do not have to explicitly give the name.
*
* @param classfile the class file.
* @see #makeClass(InputStream)
* @see javassist.ByteArrayClassPath
* @since 3.9
*/
public CtClass makeClassIfNew(InputStream classfile)
throws IOException, RuntimeException
{
compress();
classfile = new BufferedInputStream(classfile);
CtClass clazz = new CtClassType(classfile, this);
clazz.checkModify();
String classname = clazz.getName();
CtClass found = checkNotExists(classname);
if (found != null) {
return found;
} else {
cacheCtClass(classname, clazz, true);
return clazz;
}
}
/**
* Creates a new public class.
* If there already exists a class with the same name, the new class
* overwrites that previous class.
*
*
If no constructor is explicitly added to the created new
* class, Javassist generates constructors and adds it when
* the class file is generated. It generates a new constructor
* for each constructor of the super class. The new constructor
* takes the same set of parameters and invokes the
* corresponding constructor of the super class. All the received
* parameters are passed to it.
*
* @param classname a fully-qualified class name.
* @throws RuntimeException if the existing class is frozen.
*/
public CtClass makeClass(String classname) throws RuntimeException {
return makeClass(classname, null);
}
/**
* Creates a new public class.
* If there already exists a class/interface with the same name,
* the new class overwrites that previous class.
*
*
If no constructor is explicitly added to the created new
* class, Javassist generates constructors and adds it when
* the class file is generated. It generates a new constructor
* for each constructor of the super class. The new constructor
* takes the same set of parameters and invokes the
* corresponding constructor of the super class. All the received
* parameters are passed to it.
*
* @param classname a fully-qualified class name.
* @param superclass the super class.
* @throws RuntimeException if the existing class is frozen.
*/
public synchronized CtClass makeClass(String classname, CtClass superclass)
throws RuntimeException
{
checkNotFrozen(classname);
CtClass clazz = new CtNewClass(classname, this, false, superclass);
cacheCtClass(classname, clazz, true);
return clazz;
}
/**
* Creates a new public nested class.
* This method is called by CtClassType.makeNestedClass().
*
* @param classname a fully-qualified class name.
* @return the nested class.
*/
synchronized CtClass makeNestedClass(String classname) {
checkNotFrozen(classname);
CtClass clazz = new CtNewNestedClass(classname, this, false, null);
cacheCtClass(classname, clazz, true);
return clazz;
}
/**
* Creates a new public interface.
* If there already exists a class/interface with the same name,
* the new interface overwrites that previous one.
*
* @param name a fully-qualified interface name.
* @throws RuntimeException if the existing interface is frozen.
*/
public CtClass makeInterface(String name) throws RuntimeException {
return makeInterface(name, null);
}
/**
* Creates a new public interface.
* If there already exists a class/interface with the same name,
* the new interface overwrites that previous one.
*
* @param name a fully-qualified interface name.
* @param superclass the super interface.
* @throws RuntimeException if the existing interface is frozen.
*/
public synchronized CtClass makeInterface(String name, CtClass superclass)
throws RuntimeException
{
checkNotFrozen(name);
CtClass clazz = new CtNewClass(name, this, true, superclass);
cacheCtClass(name, clazz, true);
return clazz;
}
/**
* Appends the system search path to the end of the
* search path. The system search path
* usually includes the platform library, extension
* libraries, and the search path specified by the
* -classpath option or the CLASSPATH
* environment variable.
*
* @return the appended class path.
*/
public ClassPath appendSystemPath() {
return source.appendSystemPath();
}
/**
* Insert a ClassPath object at the head of the
* search path.
*
* @return the inserted class path.
* @see javassist.ClassPath
* @see javassist.URLClassPath
* @see javassist.ByteArrayClassPath
*/
public ClassPath insertClassPath(ClassPath cp) {
return source.insertClassPath(cp);
}
/**
* Appends a ClassPath object to the end of the
* search path.
*
* @return the appended class path.
* @see javassist.ClassPath
* @see javassist.URLClassPath
* @see javassist.ByteArrayClassPath
*/
public ClassPath appendClassPath(ClassPath cp) {
return source.appendClassPath(cp);
}
/**
* Inserts a directory or a jar (or zip) file at the head of the
* search path.
*
* @param pathname the path name of the directory or jar file.
* It must not end with a path separator ("/").
* If the path name ends with "/*", then all the
* jar files matching the path name are inserted.
*
* @return the inserted class path.
* @throws NotFoundException if the jar file is not found.
*/
public ClassPath insertClassPath(String pathname)
throws NotFoundException
{
return source.insertClassPath(pathname);
}
/**
* Appends a directory or a jar (or zip) file to the end of the
* search path.
*
* @param pathname the path name of the directory or jar file.
* It must not end with a path separator ("/").
* If the path name ends with "/*", then all the
* jar files matching the path name are appended.
*
* @return the appended class path.
* @throws NotFoundException if the jar file is not found.
*/
public ClassPath appendClassPath(String pathname)
throws NotFoundException
{
return source.appendClassPath(pathname);
}
/**
* Detatches the ClassPath object from the search path.
* The detached ClassPath object cannot be added
* to the pathagain.
*/
public void removeClassPath(ClassPath cp) {
source.removeClassPath(cp);
}
/**
* Appends directories and jar files for search.
*
*
The elements of the given path list must be separated by colons
* in Unix or semi-colons in Windows.
*
* @param pathlist a (semi)colon-separated list of
* the path names of directories and jar files.
* The directory name must not end with a path
* separator ("/").
* @throws NotFoundException if a jar file is not found.
*/
public void appendPathList(String pathlist) throws NotFoundException {
char sep = File.pathSeparatorChar;
int i = 0;
for (;;) {
int j = pathlist.indexOf(sep, i);
if (j < 0) {
appendClassPath(pathlist.substring(i));
break;
}
else {
appendClassPath(pathlist.substring(i, j));
i = j + 1;
}
}
}
//
// /**
// * Converts the given class to a java.lang.Class object.
// * Once this method is called, further modifications are not
// * allowed any more.
// * To load the class, this method uses the context class loader
// * of the current thread. It is obtained by calling
// * getClassLoader().
// *
// *
This behavior can be changed by subclassing the pool and changing
// * the getClassLoader() method.
// * If the program is running on some application
// * server, the context class loader might be inappropriate to load the
// * class.
// *
// *
This method is provided for convenience. If you need more
// * complex functionality, you should write your own class loader.
// *
// *
Warining: A Class object returned by this method may not
// * work with a security manager or a signed jar file because a
// * protection domain is not specified.
// *
// * @see #toClass(CtClass, java.lang.ClassLoader, ProtectionDomain)
// * @see #getClassLoader()
// */
// public Class toClass(CtClass clazz) throws CannotCompileException {
// // Some subclasses of ClassPool may override toClass(CtClass,ClassLoader).
// // So we should call that method instead of toClass(.., ProtectionDomain).
// return toClass(clazz, getClassLoader());
// }
/**
* Get the classloader for toClass(), getAnnotations() in
* CtClass, etc.
*
*
The default is the context class loader.
*
* @return the classloader for the pool
* @see #toClass(CtClass)
* @see CtClass#getAnnotations()
*/
public ClassLoader getClassLoader() {
return getContextClassLoader();
}
/**
* Obtains a class loader that seems appropriate to look up a class
* by name.
*/
static ClassLoader getContextClassLoader() {
return Thread.currentThread().getContextClassLoader();
}
}