1 files changed, 237 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/interface-java-jaxrs/src/main/java/org/apache/tuscany/sca/interfacedef/java/jaxrs/RootResourceClassGenerator.java b/sca-java-2.x/tags/2.0.1-RC1/modules/interface-java-jaxrs/src/main/java/org/apache/tuscany/sca/interfacedef/java/jaxrs/RootResourceClassGenerator.java
new file mode 100644
index 0000000000..4209ee92f6
--- /dev/null
+++ b/sca-java-2.x/tags/2.0.1-RC1/modules/interface-java-jaxrs/src/main/java/org/apache/tuscany/sca/interfacedef/java/jaxrs/RootResourceClassGenerator.java
@@ -0,0 +1,237 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.tuscany.sca.interfacedef.java.jaxrs;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+import org.objectweb.asm.AnnotationVisitor;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.FieldVisitor;
+import org.objectweb.asm.Label;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+
+public class RootResourceClassGenerator implements Opcodes {
+
+    private static final String DELEGATE_FIELD = "delegate";
+
+    public static Class<?> generateRootResourceClass(Class<?> interfaze, String path, String consumes, String produces)
+        throws Exception {
+        if (!interfaze.isInterface()) {
+            throw new IllegalArgumentException(interfaze + " is not an interface.");
+        }
+        GeneratedClassLoader classLoader = new GeneratedClassLoader(interfaze.getClassLoader());
+        String interfaceName = interfaze.getName();
+        int index = interfaze.getName().lastIndexOf('.');
+        String className =
+            interfaceName.substring(0, index) + ".Generated" + interfaceName.substring(index + 1) + "Impl";
+
+        final byte[] content = generate(interfaze, path, consumes, produces);
+        Class<?> cls = classLoader.getGeneratedClass(className, content);
+        return cls;
+    }
+
+    public static void injectProxy(Class<?> generatedResourceClass, Object proxy) throws Exception {
+        Field field = generatedResourceClass.getField("delegate");
+        field.set(null, proxy);
+    }
+
+    public static byte[] generate(Class<?> interfaze, String path, String consumes, String produces) throws Exception {
+        String interfaceName = Type.getInternalName(interfaze);
+        int index = interfaceName.lastIndexOf('/');
+        String className =
+            interfaceName.substring(0, index) + "/Generated" + interfaceName.substring(index + 1) + "Impl";
+
+        ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
+
+        declareClass(cw, interfaceName, className);
+
+        annotatePath(cw, path);
+        annotateContentTypes(cw, consumes, produces);
+        declareField(cw, interfaceName);
+        declareConstructor(cw, className);
+
+        for (Method method : interfaze.getMethods()) {
+            if (!(method.getDeclaringClass() == Object.class)) {
+                generateMethod(cw, interfaceName, className, method, consumes, produces);
+            }
+        }
+        cw.visitEnd();
+
+        return cw.toByteArray();
+    }
+
+    // public <ReturnType> method(<Type0> arg0, ..., <TypeN> argN) throws <ExpectionType0>, ..., <ExceptionTypeK>
+    private static void generateMethod(ClassWriter cw,
+                                       String interfaceName,
+                                       String className,
+                                       Method method,
+                                       String consumes,
+                                       String produces) {
+        String methodDescriptor = Type.getMethodDescriptor(method);
+
+        String signatureString = getSignature(method);
+
+        MethodVisitor mv =
+            cw.visitMethod(ACC_PUBLIC,
+                           method.getName(),
+                           methodDescriptor,
+                           signatureString,
+                           getExceptionInternalNames(method));
+
+        mv.visitCode();
+        mv.visitFieldInsn(GETSTATIC, className, DELEGATE_FIELD, getSignature(interfaceName));
+        Class<?>[] paramTypes = method.getParameterTypes();
+        int index = 1;
+        for (int i = 0; i < paramTypes.length; i++) {
+            String signature = Type.getDescriptor(paramTypes[i]);
+            mv.visitVarInsn(CodeGenerationHelper.getLoadOPCode(signature), index);
+            if(paramTypes[i] == long.class || paramTypes[i] == double.class) {
+                index+=2; // Increase the index by 2 for the 64bit numbers
+            } else {
+                index++;
+            }
+        }
+        mv.visitMethodInsn(INVOKEINTERFACE, interfaceName, method.getName(), methodDescriptor);
+
+        Class<?> returnType = method.getReturnType();
+        mv.visitInsn(CodeGenerationHelper.getReturnOPCode(Type.getDescriptor(returnType)));
+        int size = paramTypes.length + 1;
+        mv.visitMaxs(size, size);
+        mv.visitEnd();
+    }
+
+    /**
+     * [rfeng] A hack to get the generic method signature
+     * @param method
+     * @return
+     */
+    private static String getSignature(Method method) {
+        try {
+            Field field = method.getClass().getDeclaredField("signature");
+            field.setAccessible(true);
+            return (String)field.get(method);
+        } catch (Throwable e) {
+            return null;
+        }
+    }
+
+    private static String[] getExceptionInternalNames(Method method) {
+        Class<?>[] types = method.getExceptionTypes();
+        if (types.length == 0) {
+            return null;
+        }
+        String[] names = new String[types.length];
+        for (int i = 0; i < types.length; i++) {
+            names[i] = Type.getInternalName(types[i]);
+        }
+        return names;
+    }
+
+    private static String getSignature(String interfaceName) {
+        return "L" + interfaceName + ";";
+    }
+
+    private static void declareConstructor(ClassWriter cw, String className) {
+        MethodVisitor mv;
+        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
+        mv.visitCode();
+        Label l0 = new Label();
+        mv.visitLabel(l0);
+        // mv.visitLineNumber(37, l0);
+        mv.visitVarInsn(ALOAD, 0);
+        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
+        mv.visitInsn(RETURN);
+        Label l1 = new Label();
+        mv.visitLabel(l1);
+        mv.visitLocalVariable("this", getSignature(className), null, l0, l1, 0);
+        mv.visitMaxs(1, 1);
+        mv.visitEnd();
+    }
+
+    // public static <Interface> delegate;
+    private static void declareField(ClassWriter cw, String interfaceName) {
+        FieldVisitor fv =
+            cw.visitField(ACC_PUBLIC + ACC_STATIC, DELEGATE_FIELD, getSignature(interfaceName), null, null);
+        fv.visitEnd();
+    }
+
+    // public class _<Interface>Impl implements <Interface>
+    private static void declareClass(ClassWriter cw, String interfaceName, String className) {
+        cw.visit(V1_5, ACC_PUBLIC + ACC_SUPER, className, null, "java/lang/Object", new String[] {interfaceName});
+    }
+
+    // @Path(<path>)
+    private static void annotatePath(ClassWriter cw, String path) {
+        AnnotationVisitor av = cw.visitAnnotation("Ljavax/ws/rs/Path;", true);
+        av.visit("value", path);
+        av.visitEnd();
+    }
+
+    // @Consumes(<contentTypes>)
+    // @Provides(<contentTypes>)
+    private static void annotateContentTypes(ClassWriter cw, String consumes, String produces) {
+        AnnotationVisitor av = null;
+        if (consumes != null) {
+            av = cw.visitAnnotation("Ljavax/ws/rs/Consumes;", true);
+            AnnotationVisitor av1 = av.visitArray("value");
+            for (String s : consumes.split("(,| )")) {
+                av1.visit(null, s.trim());
+            }
+            av1.visitEnd();
+            av.visitEnd();
+        }
+        if (produces != null) {
+            av = cw.visitAnnotation("Ljavax/ws/rs/Produces;", true);
+            AnnotationVisitor av1 = av.visitArray("value");
+            for (String s : produces.split("(,| )")) {
+                av1.visit(null, s.trim());
+            }
+            av1.visitEnd();
+            av.visitEnd();
+        }
+    }
+
+    // @Consumes(<contentTypes>)
+    // @Provides(<contentTypes>)
+    private static void annotateContentTypes(MethodVisitor mv, String consumes, String produces) {
+        AnnotationVisitor av = null;
+        if (consumes != null) {
+            av = mv.visitAnnotation("Ljavax/ws/rs/Consumes;", true);
+            AnnotationVisitor av1 = av.visitArray("value");
+            for (String s : consumes.split("(,| )")) {
+                av1.visit(null, s.trim());
+            }
+            av1.visitEnd();
+            av.visitEnd();
+        }
+        if (produces != null) {
+            av = mv.visitAnnotation("Ljavax/ws/rs/Produces;", true);
+            AnnotationVisitor av1 = av.visitArray("value");
+            for (String s : produces.split("(,| )")) {
+                av1.visit(null, s.trim());
+            }
+            av1.visitEnd();
+            av.visitEnd();
+        }
+    }
+}