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 
11 namespace {
12 
13 // Internal version that does not use a scoped local pointer.
ConvertUTF16ToJavaStringImpl(JNIEnv * env,const base::StringPiece16 & str)14 jstring 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 }  // namespace
22 
23 namespace base {
24 namespace android {
25 
ConvertJavaStringToUTF8(JNIEnv * env,jstring str,std::string * result)26 void ConvertJavaStringToUTF8(JNIEnv* env, jstring str, std::string* result) {
27   DCHECK(str);
28   if (!str) {
29     LOG(WARNING) << "ConvertJavaStringToUTF8 called with null string.";
30     result->clear();
31     return;
32   }
33   const jsize length = env->GetStringLength(str);
34   if (!length) {
35     result->clear();
36     CheckException(env);
37     return;
38   }
39   // JNI's GetStringUTFChars() returns strings in Java "modified" UTF8, so
40   // instead get the String in UTF16 and convert using chromium's conversion
41   // function that yields plain (non Java-modified) UTF8.
42   const jchar* chars = env->GetStringChars(str, NULL);
43   DCHECK(chars);
44   UTF16ToUTF8(chars, length, result);
45   env->ReleaseStringChars(str, chars);
46   CheckException(env);
47 }
48 
ConvertJavaStringToUTF8(JNIEnv * env,jstring str)49 std::string ConvertJavaStringToUTF8(JNIEnv* env, jstring str) {
50   std::string result;
51   ConvertJavaStringToUTF8(env, str, &result);
52   return result;
53 }
54 
ConvertJavaStringToUTF8(const JavaRef<jstring> & str)55 std::string ConvertJavaStringToUTF8(const JavaRef<jstring>& str) {
56   return ConvertJavaStringToUTF8(AttachCurrentThread(), str.obj());
57 }
58 
ConvertJavaStringToUTF8(JNIEnv * env,const JavaRef<jstring> & str)59 std::string ConvertJavaStringToUTF8(JNIEnv* env, const JavaRef<jstring>& str) {
60   return ConvertJavaStringToUTF8(env, str.obj());
61 }
62 
ConvertUTF8ToJavaString(JNIEnv * env,const base::StringPiece & str)63 ScopedJavaLocalRef<jstring> ConvertUTF8ToJavaString(
64     JNIEnv* env,
65     const base::StringPiece& str) {
66   // JNI's NewStringUTF expects "modified" UTF8 so instead create the string
67   // via our own UTF16 conversion utility.
68   // Further, Dalvik requires the string passed into NewStringUTF() to come from
69   // a trusted source. We can't guarantee that all UTF8 will be sanitized before
70   // it gets here, so constructing via UTF16 side-steps this issue.
71   // (Dalvik stores strings internally as UTF16 anyway, so there shouldn't be
72   // a significant performance hit by doing it this way).
73   return ScopedJavaLocalRef<jstring>(env, ConvertUTF16ToJavaStringImpl(
74       env, UTF8ToUTF16(str)));
75 }
76 
ConvertJavaStringToUTF16(JNIEnv * env,jstring str,string16 * result)77 void ConvertJavaStringToUTF16(JNIEnv* env, jstring str, string16* result) {
78   DCHECK(str);
79   if (!str) {
80     LOG(WARNING) << "ConvertJavaStringToUTF16 called with null string.";
81     result->clear();
82     return;
83   }
84   const jsize length = env->GetStringLength(str);
85   if (!length) {
86     result->clear();
87     CheckException(env);
88     return;
89   }
90   const jchar* chars = env->GetStringChars(str, NULL);
91   DCHECK(chars);
92   // GetStringChars isn't required to NULL-terminate the strings
93   // it returns, so the length must be explicitly checked.
94   result->assign(chars, length);
95   env->ReleaseStringChars(str, chars);
96   CheckException(env);
97 }
98 
ConvertJavaStringToUTF16(JNIEnv * env,jstring str)99 string16 ConvertJavaStringToUTF16(JNIEnv* env, jstring str) {
100   string16 result;
101   ConvertJavaStringToUTF16(env, str, &result);
102   return result;
103 }
104 
ConvertJavaStringToUTF16(const JavaRef<jstring> & str)105 string16 ConvertJavaStringToUTF16(const JavaRef<jstring>& str) {
106   return ConvertJavaStringToUTF16(AttachCurrentThread(), str.obj());
107 }
108 
ConvertJavaStringToUTF16(JNIEnv * env,const JavaRef<jstring> & str)109 string16 ConvertJavaStringToUTF16(JNIEnv* env, const JavaRef<jstring>& str) {
110   return ConvertJavaStringToUTF16(env, str.obj());
111 }
112 
ConvertUTF16ToJavaString(JNIEnv * env,const base::StringPiece16 & str)113 ScopedJavaLocalRef<jstring> ConvertUTF16ToJavaString(
114     JNIEnv* env,
115     const base::StringPiece16& str) {
116   return ScopedJavaLocalRef<jstring>(env,
117                                      ConvertUTF16ToJavaStringImpl(env, str));
118 }
119 
120 }  // namespace android
121 }  // namespace base
122