load javassist related classes via reflection

Author: komamitsu

src/main/java/org/msgpack/template/builder/AbstractTemplateBuilder.java

@@ -21,6 +21,8 @@
 import java.lang.reflect.AccessibleObject;
 import java.lang.reflect.Field;
 import java.lang.reflect.GenericArrayType;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
@@ -41,8 +43,26 @@
 import org.msgpack.template.Template;
 import org.msgpack.template.TemplateRegistry;
 import org.msgpack.template.builder.TemplateBuildException;
+import org.msgpack.util.android.DalvikVmChecker;
 
 public abstract class AbstractTemplateBuilder implements TemplateBuilder {
+ 
+ private static final Method javassistModifierIsAbstractMethod;
+ static {
+ Method method = null;
+ try {
+ if (!DalvikVmChecker.isDalvikVm()) {
+ Class<?> clazz = Class.forName("javassist.Modifier");
+ method = clazz.getMethod("isAbstract", int.class);
+ }
+ } catch (ClassNotFoundException e) {
+ // DalvikVM
+ } catch (NoSuchMethodException e) {
+ // TODO: should output any message ?
+ } finally {
+ javassistModifierIsAbstractMethod = method;
+ }
+ }
 
  protected TemplateRegistry registry;
 
@@ -72,10 +92,19 @@ public <T> Template<T> buildTemplate(final Class<T> targetClass, final FieldList
  protected abstract <T> Template<T> buildTemplate(Class<T> targetClass, FieldEntry[] entries);
 
  protected void checkClassValidation(final Class<?> targetClass) {
- if (javassist.Modifier.isAbstract(targetClass.getModifiers())) {
- throw new TemplateBuildException(
- "Cannot build template for abstract class: " + targetClass.getName());
+ if (javassistModifierIsAbstractMethod != null) {
+ try {
+ if ((Boolean) javassistModifierIsAbstractMethod.invoke(null, targetClass.getModifiers())) {
+ throw new TemplateBuildException(
+ "Cannot build template for abstract class: " + targetClass.getName());
+ }
+ } catch (IllegalAccessException e) {
+ new TemplateBuildException(e);
+ } catch (InvocationTargetException e) {
+ new TemplateBuildException(e);
+ }
  }
+ 
  if (targetClass.isInterface()) {
  throw new TemplateBuildException(
  "Cannot build template for interface: " + targetClass.getName());

src/main/java/org/msgpack/template/builder/TemplateBuilderChain.java

@@ -17,6 +17,8 @@
 //
 package org.msgpack.template.builder;
 
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.List;
@@ -29,6 +31,24 @@ public class TemplateBuilderChain {
  private static boolean enableDynamicCodeGeneration() {
  return !DalvikVmChecker.isDalvikVm();
  }
+ 
+ private static final Constructor<?> javassistTemplateBuilderConstructor;
+ static {
+ Constructor<?> constructor = null;
+ try {
+ if (!DalvikVmChecker.isDalvikVm()) {
+ Class<?> clazz = Class.forName("org.msgpack.template.builder.JavassistTemplateBuilder");
+ constructor = clazz.getConstructor(TemplateRegistry.class, ClassLoader.class);
+ }
+ } catch (ClassNotFoundException e) {
+ // DalvikVM
+ } catch (NoSuchMethodException e) {
+ // TODO: should output any message ?
+ }
+ finally {
+ javassistTemplateBuilderConstructor = constructor;
+ }
+ }
 
  protected List<TemplateBuilder> templateBuilders;
 
@@ -51,22 +71,37 @@ protected void reset(final TemplateRegistry registry, final ClassLoader cl) {
  // FIXME
  // Javassist{,Beans}TemplateBuilder should be created with reflection for android.
 
- // forceBuilder
- forceBuilder = new JavassistTemplateBuilder(registry, cl);
+ TemplateBuilder javassistTemplateBuilder = null;
+ if (javassistTemplateBuilderConstructor != null) {
+ try {
+ javassistTemplateBuilder = (TemplateBuilder) javassistTemplateBuilderConstructor.newInstance(registry, cl);
+ } catch (InstantiationException e) {
+ new IllegalStateException(e);
+ } catch (IllegalAccessException e) {
+ new IllegalStateException(e);
+ } catch (InvocationTargetException e) {
+ new IllegalStateException(e);
+ }
+ }
 
  // builder
  TemplateBuilder builder;
  templateBuilders.add(new ArrayTemplateBuilder(registry));
  templateBuilders.add(new OrdinalEnumTemplateBuilder(registry));
- if (enableDynamicCodeGeneration()) { // use dynamic code generation
+ if (enableDynamicCodeGeneration() && javassistTemplateBuilder != null) { // use dynamic code generation
+ // forceBuilder
+ forceBuilder = javassistTemplateBuilder;
+ 
  builder = forceBuilder;
  templateBuilders.add(builder);
  // FIXME #MN next version
  // templateBuilders.add(new
  // JavassistBeansTemplateBuilder(registry));
  templateBuilders.add(new ReflectionBeansTemplateBuilder(registry));
  } else { // use reflection
- builder = new ReflectionTemplateBuilder(registry);
+ // forceBuilder
+ forceBuilder = new ReflectionTemplateBuilder(registry);
+ builder = forceBuilder;
  templateBuilders.add(builder);
  templateBuilders.add(new ReflectionBeansTemplateBuilder(registry));
  }