com.google.security.fences.AbstractClassesVisitor Maven / Gradle / Ivy
package com.google.security.fences;
import java.io.IOException;
import java.io.InputStream;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import com.google.common.base.Predicate;
/**
* Visits all the classes performing some operation.
*/
abstract class AbstractClassesVisitor {
/** Called to construct an ASM ClassVisitor which is then visited. */
protected abstract ClassVisitor makeVisitorForClass(
ClassRoot root, String relPath, ClassReader r)
throws IOException;
/** Called before the classes in a root are enumerated. */
@SuppressWarnings("unused")
protected void startClassRoot(ClassRoot cr) throws IOException {
// Does nothing by default
}
/** Called after the last class, if any, in a root has been visited. */
@SuppressWarnings("unused")
protected void finishClassRoot(ClassRoot cr) throws IOException {
// Does nothing by default
}
/**
* Visits all the given roots in order.
* The order in which classes under a root are visited depends on the
* underlying file-system.
*/
final void visitAll(Iterable roots)
throws IOException {
for (ClassRoot root : roots) {
startClassRoot(root);
root.readEachPathMatching(
new Predicate() {
public boolean apply(String relativePath) {
return relativePath.endsWith(".class");
}
},
new ClassRoot.IOConsumer() {
public Boolean consume(
ClassRoot cr, String relPath, InputStream is)
throws IOException {
ClassReader reader = new ClassReader(is);
ClassVisitor classChecker = makeVisitorForClass(
cr, relPath, reader);
reader.accept(classChecker, 0 /* flags */);
return true;
}
});
finishClassRoot(root);
}
}
}