Always load java.* classes by delegating to the bootstrap class loader

Fixes #34 for real

Author: luontola

.idea/libraries/Maven__net_orfjackal_retrolambda_java_lang_dummies_1.xml

@@ -147,6 +147,8 @@ Version History
 
 - Backports static methods on interfaces
   ([Issue #31](https://github.com/orfjackal/retrolambda/issues/31))
+- Fixed a crash when trying backport Android classes
+  ([Issue #34](https://github.com/orfjackal/retrolambda/issues/34))
 
 ### Retrolambda 1.6.1 (2014-08-25)
 

README.md

@@ -13,6 +13,7 @@
     <orderEntry type="library" name="Maven: com.google.guava:guava:11.0.2" level="project" />
     <orderEntry type="library" name="Maven: com.google.code.findbugs:jsr305:1.3.9" level="project" />
     <orderEntry type="library" scope="TEST" name="Maven: commons-lang:commons-lang:2.6" level="project" />
+    <orderEntry type="library" name="Maven: net.orfjackal.retrolambda:java-lang-dummies:1" level="project" />
     <orderEntry type="library" scope="TEST" name="Maven: junit:junit:4.11" level="project" />
     <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-library:1.3" level="project" />
     <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />

end-to-end-tests/end-to-end-tests.iml

@@ -28,6 +28,15 @@
             <scope>test</scope>
         </dependency>
 
+        <!-- See net.orfjackal.retrolambda.test.ClasspathTest#ignores_classes_in_explicit_classpath_that_are_under_the_java_package -->
+        <dependency>
+            <groupId>net.orfjackal.retrolambda</groupId>
+            <artifactId>java-lang-dummies</artifactId>
+            <version>1</version>
+            <scope>system</scope>
+            <systemPath>${basedir}/src/test/lib/java-lang-dummies.jar</systemPath>
+        </dependency>
+
     </dependencies>
 
     <build>

end-to-end-tests/pom.xml

@@ -7,10 +7,12 @@
 import org.hamcrest.*;
 import org.junit.Test;
 
-import java.util.Arrays;
+import java.io.IOException;
+import java.net.URL;
+import java.util.*;
 
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.assertNotNull;
 
 public class ClasspathTest {
@@ -65,7 +67,11 @@ public void prefers_classes_in_explicit_classpath_over_classes_in_the_JRE() {
      * contains {@code java.*} classes.
      */
     @Test
-    public void ignores_classes_in_explicit_classpath_that_are_under_the_java_package() {
-        assertNotNull(getClass().getResource("/java/lang/Math.class"));
+    public void ignores_classes_in_explicit_classpath_that_are_under_the_java_package() throws IOException {
+        // We have a JAR on the classpath that contains dummy version of java.lang.Object,
+        // the same way as android.jar, which causes Retrolambda to try loading that class
+        // because the classes to be backported extend it implicitly.
+        List<URL> resources = Collections.list(getClass().getClassLoader().getResources("java/lang/Object.class"));
+        assertThat(resources, (Matcher) hasItem(hasToString(containsString("java-lang-dummies.jar"))));
     }
 }

end-to-end-tests/src/test/java/java/lang/Math.java

@@ -14,6 +14,9 @@ public NonDelegatingClassLoader(URL[] urls) {
 
     @Override
     public Class<?> loadClass(String name) throws ClassNotFoundException {
+        if (name.startsWith("java.")) { // the java.* classes can only be loaded by the bootstrap class loader
+            return super.loadClass(name);
+        }
         Class<?> c = findLoadedClass(name);
         if (c != null) {
             return c;

end-to-end-tests/src/test/java/net/orfjackal/retrolambda/test/ClasspathTest.java

@@ -23,12 +23,7 @@ public class ClassHierarchyAnalyzer implements MethodRelocations {
 
     public void analyze(byte[] bytecode) {
         ClassReader cr = new ClassReader(bytecode);
-        String className = cr.getClassName();
-        if (className.startsWith("java/")) {
-            // the JVM disallows user classes in java.* packages, so don't even try backporting them
-            return;
-        }
-        Type clazz = classNameToType(className);
+        Type clazz = classNameToType(cr.getClassName());
 
         if (Flags.hasFlag(cr.getAccess(), ACC_INTERFACE)) {
             interfaces.add(cr);