Be able to create a wrapper for java.

Android is a specific wrapper.
Java is another one.

src/wrapper/java/library.cpp

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2019-2020 Matthieu Gautier <mgautier@kymeria.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU  General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+
+#include <jni.h>
+#include "org_kiwix_kiwixlib_Library.h"
+
+#include "library.h"
+#include "reader.h"
+#include "utils.h"
+
+/* Kiwix Reader JNI functions */
+JNIEXPORT void JNICALL
+Java_org_kiwix_kiwixlib_Library_allocate(
+    JNIEnv* env, jobject thisObj)
+{
+  allocate<kiwix::Library>(env, thisObj);
+}
+
+JNIEXPORT void JNICALL
+Java_org_kiwix_kiwixlib_Library_dispose(JNIEnv* env, jobject thisObj)
+{
+  dispose<kiwix::Library>(env, thisObj);
+}
+
+#define LIBRARY (getPtr<kiwix::Library>(env, thisObj))
+
+/* Kiwix library functions */
+JNIEXPORT jboolean JNICALL
+Java_org_kiwix_kiwixlib_Library_addBook(
+  JNIEnv* env, jobject thisObj, jstring path)
+{
+  auto cPath = jni2c(path, env);
+
+  try {
+    kiwix::Reader reader(cPath);
+    kiwix::Book book;
+    book.update(reader);
+    return LIBRARY->addBook(book);
+  } catch (std::exception& e) {
+    LOG("Unable to add the book");
+    LOG(e.what()); }
+  return false;
+}
+
+METHOD(jobject, Library, getBookById, jstring id) {
+  auto cId = jni2c(id, env);
+  auto cBook = new kiwix::Book(LIBRARY->getBookById(cId));
+  jclass cls = env->FindClass("org/kiwix/kiwixlib/Book");
+  jmethodID constructorId = env->GetMethodID(cls, "<init>", "()V");
+  jobject book = env->NewObject(cls, constructorId);
+  setPtr(env, book, cBook);
+  return book;
+}
+
+METHOD(jint, Library, getBookCount, jboolean localBooks, jboolean remoteBooks) {
+  return LIBRARY->getBookCount(localBooks, remoteBooks);
+}
+
+METHOD0(jobjectArray, Library, getBooksIds) {
+  return c2jni(LIBRARY->getBooksIds(), env);
+}
+
+METHOD(jobjectArray, Library, filter, jobject filterObj) {
+  auto filter = getPtr<kiwix::Filter>(env, filterObj);
+  return c2jni(LIBRARY->filter(*filter), env);
+}
+
+METHOD0(jobjectArray, Library, getBooksLanguages) {
+  return c2jni(LIBRARY->getBooksLanguages(), env);
+}
+
+METHOD0(jobjectArray, Library, getBooksCreators) {
+  return c2jni(LIBRARY->getBooksCreators(), env);
+}
+
+METHOD0(jobjectArray, Library, getBooksPublisher) {
+  return c2jni(LIBRARY->getBooksPublishers(), env);
+}
+