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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed 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.
*/
#pragma once
#include <stddef.h>
#include <jni.h>
#include "nativehelper_utils.h"
// A smart pointer that provides access to a jchar* given a JNI jstring.
// Unlike GetStringChars, we throw NullPointerException rather than abort if
// passed a null jstring, and get will return nullptr.
// This makes the correct idiom very simple:
//
// ScopedStringChars name(env, java_name);
// if (name.get() == nullptr) {
// return nullptr;
// }
class ScopedStringChars {
public:
ScopedStringChars(JNIEnv* env, jstring s) : env_(env), string_(s), size_(0) {
if (s == nullptr) {
chars_ = nullptr;
jniThrowNullPointerException(env);
} else {
chars_ = env->GetStringChars(string_, nullptr);
if (chars_ != nullptr) {
size_ = env->GetStringLength(string_);
}
}
}
~ScopedStringChars() {
if (chars_ != nullptr) {
env_->ReleaseStringChars(string_, chars_);
}
}
const jchar* get() const {
return chars_;
}
size_t size() const {
return size_;
}
const jchar& operator[](size_t n) const {
return chars_[n];
}
private:
JNIEnv* const env_;
const jstring string_;
const jchar* chars_;
size_t size_;
DISALLOW_COPY_AND_ASSIGN(ScopedStringChars);
};