[Android] Introduce a Java wrapper for TemplateUrlService.

base/android/jni_map.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/android/jni_map.h"
+
+#include <map>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "base/android/scoped_java_ref.h"
+#include "base/logging.h"
+#include "jni/HashMap_jni.h"
+#include "jni/Iterator_jni.h"
+#include "jni/Set_jni.h"
+
+namespace base {
+namespace android {
+
+// Converts a std::map<std::string, string16> to a java HashMap<String, String>.
+ScopedJavaLocalRef<jobject> ConvertMapToJavaMap(
+    JNIEnv* env,
+    const std::map<std::string,
+    string16>& cmap) {
+  ScopedJavaLocalRef<jobject> jmap(
+      JNI_HashMap::Java_HashMap_ConstructorJUHM(env));
+
+  for (std::map<std::string, string16>::const_iterator i = cmap.begin();
+       i != cmap.end(); i++) {
+    ScopedJavaLocalRef<jstring> key = ConvertUTF8ToJavaString(env, i->first);
+    ScopedJavaLocalRef<jstring> value = ConvertUTF16ToJavaString(env,
+                                                                 i->second);
+    JNI_HashMap::Java_HashMap_put(env, jmap.obj(), key.obj(), value.obj());
+  }
+  return jmap;
+}
+
+std::map<std::string, string16> ConvertJavaMapToMap(JNIEnv* env,
+                                                    jobject jmap) {
+  std::map<std::string, string16> cmap;
+
+  ScopedJavaLocalRef<jobject> jset =
+      JNI_HashMap::Java_HashMap_entrySet(env, jmap);
+  DCHECK(!jset.is_null());
+
+  ScopedJavaLocalRef<jobject> iter =
+      JNI_Set::Java_Set_iterator(env, jset.obj());
+  DCHECK(!iter.is_null());
+
+  // TODO(yfriedman): Convert this to JNI bindings when the JNI generator can
+  // support inner classes from jar files.
+  ScopedJavaLocalRef<jclass> map_entry_clazz =
+      GetClass(env, "java/util/Map$Entry");
+  jmethodID map_entry_getkey = MethodID::Get<MethodID::TYPE_INSTANCE>(
+      env, map_entry_clazz.obj(), "getKey", "()Ljava/lang/Object;");
+  jmethodID map_entry_getvalue = MethodID::Get<MethodID::TYPE_INSTANCE>(
+      env, map_entry_clazz.obj(), "getValue", "()Ljava/lang/Object;");
+
+  while (JNI_Iterator::Java_Iterator_hasNext(env, iter.obj())) {
+    ScopedJavaLocalRef<jobject> map_entry =
+        JNI_Iterator::Java_Iterator_next(env, iter.obj());
+    DCHECK(env->IsInstanceOf(map_entry.obj(), map_entry_clazz.obj()));
+    ScopedJavaLocalRef<jstring> jkey(env,
+        static_cast<jstring>(env->CallObjectMethod(map_entry.obj(),
+                                                   map_entry_getkey)));
+    ScopedJavaLocalRef<jstring> jvalue(env,
+        static_cast<jstring>(env->CallObjectMethod(map_entry.obj(),
+                                                   map_entry_getvalue)));
+    if (!jkey.is_null() && !jvalue.is_null() &&
+        env->GetStringLength(jvalue.obj())) {
+      cmap[ConvertJavaStringToUTF8(jkey)] = ConvertJavaStringToUTF16(jvalue);
+    }
+  }
+  return cmap;
+}
+
+bool RegisterMap(JNIEnv* env) {
+  return JNI_HashMap::RegisterNativesImpl(env) &&
+      JNI_Iterator::RegisterNativesImpl(env) &&
+      JNI_Set::RegisterNativesImpl(env);
+}
+
+}  // namespace android
+}  // namespace base