1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "base/android/jni_string.h"
6
7#include "base/android/jni_android.h"
8#include "base/logging.h"
9#include "base/strings/utf_string_conversions.h"
10
11namespace {
12
13// Internal version that does not use a scoped local pointer.
14jstring ConvertUTF16ToJavaStringImpl(JNIEnv* env,
15                                     const base::StringPiece16& str) {
16  jstring result = env->NewString(str.data(), str.length());
17  base::android::CheckException(env);
18  return result;
19}
20
21}
22
23namespace base {
24namespace android {
25
26void ConvertJavaStringToUTF8(JNIEnv* env, jstring str, std::string* result) {
27  if (!str) {
28    LOG(WARNING) << "ConvertJavaStringToUTF8 called with null string.";
29    result->clear();
30    return;
31  }
32  // JNI's GetStringUTFChars() returns strings in Java "modified" UTF8, so
33  // instead get the String in UTF16 and convert using chromium's conversion
34  // function that yields plain (non Java-modified) UTF8.
35  const jchar* chars = env->GetStringChars(str, NULL);
36  DCHECK(chars);
37  UTF16ToUTF8(chars, env->GetStringLength(str), result);
38  env->ReleaseStringChars(str, chars);
39  CheckException(env);
40}
41
42std::string ConvertJavaStringToUTF8(JNIEnv* env, jstring str) {
43  std::string result;
44  ConvertJavaStringToUTF8(env, str, &result);
45  return result;
46}
47
48std::string ConvertJavaStringToUTF8(const JavaRef<jstring>& str) {
49  return ConvertJavaStringToUTF8(AttachCurrentThread(), str.obj());
50}
51
52ScopedJavaLocalRef<jstring> ConvertUTF8ToJavaString(
53    JNIEnv* env,
54    const base::StringPiece& str) {
55  // JNI's NewStringUTF expects "modified" UTF8 so instead create the string
56  // via our own UTF16 conversion utility.
57  // Further, Dalvik requires the string passed into NewStringUTF() to come from
58  // a trusted source. We can't guarantee that all UTF8 will be sanitized before
59  // it gets here, so constructing via UTF16 side-steps this issue.
60  // (Dalvik stores strings internally as UTF16 anyway, so there shouldn't be
61  // a significant performance hit by doing it this way).
62  return ScopedJavaLocalRef<jstring>(env, ConvertUTF16ToJavaStringImpl(
63      env, UTF8ToUTF16(str)));
64}
65
66void ConvertJavaStringToUTF16(JNIEnv* env, jstring str, string16* result) {
67  if (!str) {
68    LOG(WARNING) << "ConvertJavaStringToUTF16 called with null string.";
69    result->clear();
70    return;
71  }
72  const jchar* chars = env->GetStringChars(str, NULL);
73  DCHECK(chars);
74  // GetStringChars isn't required to NULL-terminate the strings
75  // it returns, so the length must be explicitly checked.
76  result->assign(chars, env->GetStringLength(str));
77  env->ReleaseStringChars(str, chars);
78  CheckException(env);
79}
80
81string16 ConvertJavaStringToUTF16(JNIEnv* env, jstring str) {
82  string16 result;
83  ConvertJavaStringToUTF16(env, str, &result);
84  return result;
85}
86
87string16 ConvertJavaStringToUTF16(const JavaRef<jstring>& str) {
88  return ConvertJavaStringToUTF16(AttachCurrentThread(), str.obj());
89}
90
91ScopedJavaLocalRef<jstring> ConvertUTF16ToJavaString(
92    JNIEnv* env,
93    const base::StringPiece16& str) {
94  return ScopedJavaLocalRef<jstring>(env,
95                                     ConvertUTF16ToJavaStringImpl(env, str));
96}
97
98}  // namespace android
99}  // namespace base
100