com.google.cloud.tools.opensource.classpath

Class LinkageCheckClassPath

java.lang.Object

org.apache.bcel.util.ClassPath

com.google.cloud.tools.opensource.classpath.LinkageCheckClassPath

All Implemented Interfaces:

Closeable, AutoCloseable

public class LinkageCheckClassPath
extends org.apache.bcel.util.ClassPath

Class path to load class files for LinkageChecker. When loading a resource for a class, LinkageCheckClassPath ensures that the class file comes from only the extension class loader or the class path specified at the constructor argument.

Background: BCEL's ClassPath.getInputStream(String, String) uses the system class loader to read class files when ClassPathRepository.loadClass(String) is called, meaning that it loads other classes outside the class path specified at its constructor argument. In other words, classes used in this cloud-opensource-java project (including Guava 26) would be unexpectedly loaded by the system class loader when running linkage check, if BCEL's ClassPath is naively used.

This class is introduced to avoid the mix-up of the class paths. It loads resources only from the extension class loader, which does not include the class path of this project, or the class path specified at the constructor argument.

See Also:

BCEL's ClassPath

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.bcel.util.ClassPath

org.apache.bcel.util.ClassPath.ClassFile

Field Summary

Fields inherited from class org.apache.bcel.util.ClassPath

SYSTEM_CLASS_PATH

Method Summary

Modifier and Type	Method and Description
InputStream	getInputStream(String name, String suffix) Returns an input stream for a resource in the class path.

Methods inherited from class org.apache.bcel.util.ClassPath

close, equals, getBytes, getBytes, getClassFile, getClassFile, getClassPath, getInputStream, getPath, getPath, getResource, getResourceAsStream, getResources, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getInputStream

public InputStream getInputStream(String name,
                                  String suffix)
                           throws IOException

Returns an input stream for a resource in the class path. This uses either the extension class loader or the class path specified at the constructor argument, ensuring that the resource is not loaded from the class path of this tool itself.

Overrides:

getInputStream in class org.apache.bcel.util.ClassPath

Parameters:

name - a slash separated relative path such as "java/lang/String"

suffix - the extension of the file in the classpath such as ".class" or ".xml"

Throws:

IOException