@@ -57,6 +57,7 @@ package org.apache.tools.ant;
import java.util.*;
import java.util.zip.*;
import java.io.*;
import org.apache.tools.ant.types.Path;
/**
* Used to load classes within ant with a different claspath from that used to start ant.
@@ -75,7 +76,7 @@ public class AntClassLoader extends ClassLoader {
/**
* The classpath that is to be used when loading classes using this class loader.
*/
private org.apache.tools.ant.types. Path classpath;
private Path classpath;
/**
* The project to which this class loader belongs.
@@ -83,9 +84,22 @@ public class AntClassLoader extends ClassLoader {
private Project project;
/**
* The File components of the path. Typically these will be directories or jar files.
* Indicates whether the system class loader should be
* consulted before trying to load with this class loader.
*/
private Vector components = null;
private boolean systemFirst = true;
/**
* These are the package roots that are to be loaded by the system class loader
* regardless of whether the system class loader is being searched first or not.
*/
private Vector systemPackages = new Vector();
/**
* These are the package roots that are to be loaded by this class loader
* regardless of whether the system class loader is being searched first or not.
*/
private Vector loaderPackages = new Vector();
/**
* Create a classloader for the given project using the classpath given.
@@ -93,28 +107,47 @@ public class AntClassLoader extends ClassLoader {
* @param project the project to ehich this classloader is to belong.
* @param classpath the classpath to use to load the classes.
*/
public AntClassLoader(Project project,
org.apache.tools.ant.types.Path classpath) {
public AntClassLoader(Project project, Path classpath) {
this.project = project;
this.classpath = classpath;
}
/**
* Set up this classloader for the first time.
* Create a classloader for the given project using the classpath given.
*
* This method will set up the components field with the components from the
* given classpath.
* @param project the project to ehich this classloader is to belong.
* @param classpath the classpath to use to load the classes.
*/
private void setup() {
// We iterate through the class path, resolving each element.
components = new Vector();
String[] pathElements = classpath.list();
for (int i = 0; i < pathElements.length; ++i) {
File element = project.resolveFile(pathElements[i]);
components.addElement(element);
}
public AntClassLoader(Project project, Path classpath, boolean systemFirst) {
this(project, classpath);
this.systemFirst = systemFirst;
}
/**
* Add a package root to the list of packages which must be loaded on the
* system loader.
*
* All subpackages are also included.
*
* @param packageRoot the root of akll packages to be included.
*/
public void addSystemPackageRoot(String packageRoot) {
systemPackages.addElement(packageRoot + ".");
}
/**
* Add a package root to the list of packages which must be loaded using
* this loader.
*
* All subpackages are also included.
*
* @param packageRoot the root of akll packages to be included.
*/
public void addLoaderPackageRoot(String packageRoot) {
loaderPackages.addElement(packageRoot + ".");
}
/**
* Load a class through this class loader even if that class is available on the
@@ -131,6 +164,7 @@ public class AntClassLoader extends ClassLoader {
* this loader's classpath.
*/
public Class forceLoadClass(String classname) throws ClassNotFoundException {
project.log("force loading " + classname, Project.MSG_VERBOSE);
Class theClass = findLoadedClass(classname);
if (theClass == null) {
@@ -140,6 +174,30 @@ public class AntClassLoader extends ClassLoader {
return theClass;
}
/**
* Load a class through this class loader but defer to the system class loader
*
* This ensures that instances of the returned class will be compatible with instances which
* which have already been loaded on the system loader.
*
* @param classname the classname to be loaded.
*
* @return the required Class object
*
* @throws ClassNotFoundException if the requested class does not exist on
* this loader's classpath.
*/
public Class forceLoadSystemClass(String classname) throws ClassNotFoundException {
project.log("force system loading " + classname, Project.MSG_VERBOSE);
Class theClass = findLoadedClass(classname);
if (theClass == null) {
theClass = findSystemClass(classname);
}
return theClass;
}
/**
* Get a stream to read the requested resource name.
*
@@ -149,17 +207,13 @@ public class AntClassLoader extends ClassLoader {
* found on the loader's classpath.
*/
public InputStream getResourceAsStream(String name) {
if (components == null) {
// we haven't set up the list of directories and jars yet.
setup();
}
// we need to search the components of the path to see if we can find the
// class we want.
InputStream stream = null;
for (Enumeration e = components.elements(); e.hasMoreElements() && stream == null; ) {
File pathComponent = (File)e.nextElement();
String[] pathElements = classpath.list();
for (int i = 0; i < pathElements.length && stream == null; ++i) {
File pathComponent = project.resolveFile((String)pathElements[i]);
stream = getResourceStream(pathComponent, name);
}
@@ -168,7 +222,7 @@ public class AntClassLoader extends ClassLoader {
/**
* Get an inputstream to a given resource in the given file which may
* either be a directory or a jar type file.
* either be a directory or a zip file.
*
* @param file the file (directory or jar) in which to search for the resource.
* @param resourceName the name of the resource for which a stream is required.
@@ -184,6 +238,7 @@ public class AntClassLoader extends ClassLoader {
if (file.isDirectory()) {
File resource = new File(file, resourceName);
if (resource.exists()) {
return new FileInputStream(resource);
}
@@ -238,14 +293,49 @@ public class AntClassLoader extends ClassLoader {
* the system classpath or this loader's classpath.
*/
protected Class loadClass(String classname, boolean resolve) throws ClassNotFoundException {
// default to the global setting and then see
// if this class belongs to a package which has been
// designated to use a specific loader first (this one or the system one)
boolean useSystemFirst = systemFirst;
for (Enumeration e = systemPackages.elements(); e.hasMoreElements();) {
String packageName = (String)e.nextElement();
if (classname.startsWith(packageName)) {
useSystemFirst = true;
break;
}
}
for (Enumeration e = loaderPackages.elements(); e.hasMoreElements();) {
String packageName = (String)e.nextElement();
if (classname.startsWith(packageName)) {
useSystemFirst = false;
break;
}
}
Class theClass = findLoadedClass(classname);
if (theClass == null) {
try {
theClass = findSystemClass(classname);
if (useSystemFirst) {
try {
theClass = findSystemClass(classname);
project.log("Class " + classname + " loaded from system loader", Project.MSG_VERBOSE);
}
catch (ClassNotFoundException cnfe) {
theClass = findClass(classname);
project.log("Class " + classname + " loaded from ant loader", Project.MSG_VERBOSE);
}
}
catch (ClassNotFoundException cnfe) {
theClass = findClass(classname);
else {
try {
theClass = findClass(classname);
project.log("Class " + classname + " loaded from ant loader", Project.MSG_VERBOSE);
}
catch (ClassNotFoundException cnfe) {
theClass = findSystemClass(classname);
project.log("Class " + classname + " loaded from system loader", Project.MSG_VERBOSE);
}
}
}
@@ -294,6 +384,7 @@ public class AntClassLoader extends ClassLoader {
return defineClass(classname, classData, 0, classData.length);
}
/**
* Search for and load a class on the classpath of this class loader.
*
@@ -305,18 +396,29 @@ public class AntClassLoader extends ClassLoader {
* this loader's classpath.
*/
public Class findClass(String name) throws ClassNotFoundException {
if (components == null) {
// we haven't set up the list of directories and jars yet.
setup();
project.log("Finding class " + name, Project.MSG_VERBOSE);
try {
return findClass(name, classpath);
}
catch (ClassNotFoundException e) {
throw e;
}
}
/**
* Find a class on the given classpath.
*/
private Class findClass(String name, Path path) throws ClassNotFoundException {
// we need to search the components of the path to see if we can find the
// class we want.
InputStream stream = null;
String classFilename = getClassFilename(name);
try {
for (Enumeration e = components.elements(); e.hasMoreElements() && stream == null; ) {
File pathComponent = (File)e.nextElement();
String[] pathElements = path.list();
for (int i = 0; i < pathElements.length && stream == null; ++i) {
File pathComponent = project.resolveFile((String)pathElements[i]);
stream = getResourceStream(pathComponent, classFilename);
}
Conor MacNeill