1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "JniConstants.h"
18 #include "toStringArray.h"
19
20 #include <string>
21 #include <vector>
22
23 struct VectorCounter {
24 const std::vector<std::string>& strings;
VectorCounterVectorCounter25 VectorCounter(const std::vector<std::string>& strings) : strings(strings) {}
operator ()VectorCounter26 size_t operator()() {
27 return strings.size();
28 }
29 };
30 struct VectorGetter {
31 const std::vector<std::string>& strings;
VectorGetterVectorGetter32 VectorGetter(const std::vector<std::string>& strings) : strings(strings) {}
operator ()VectorGetter33 const char* operator()(size_t i) {
34 return strings[i].c_str();
35 }
36 };
37
toStringArray(JNIEnv * env,const std::vector<std::string> & strings)38 jobjectArray toStringArray(JNIEnv* env, const std::vector<std::string>& strings) {
39 VectorCounter counter(strings);
40 VectorGetter getter(strings);
41 return toStringArray<VectorCounter, VectorGetter>(env, &counter, &getter);
42 }
43
44 struct ArrayCounter {
45 const char* const* strings;
ArrayCounterArrayCounter46 ArrayCounter(const char* const* strings) : strings(strings) {}
operator ()ArrayCounter47 size_t operator()() {
48 size_t count = 0;
49 while (strings[count] != NULL) {
50 ++count;
51 }
52 return count;
53 }
54 };
55
56 struct ArrayGetter {
57 const char* const* strings;
ArrayGetterArrayGetter58 ArrayGetter(const char* const* strings) : strings(strings) {}
operator ()ArrayGetter59 const char* operator()(size_t i) {
60 return strings[i];
61 }
62 };
63
toStringArray(JNIEnv * env,const char * const * strings)64 jobjectArray toStringArray(JNIEnv* env, const char* const* strings) {
65 ArrayCounter counter(strings);
66 ArrayGetter getter(strings);
67 return toStringArray(env, &counter, &getter);
68 }
69
70 /** Converts a Java String[] to a 0-terminated char**. */
convertStrings(JNIEnv * env,jobjectArray javaArray)71 char** convertStrings(JNIEnv* env, jobjectArray javaArray) {
72 if (javaArray == NULL) {
73 return NULL;
74 }
75
76 jsize length = env->GetArrayLength(javaArray);
77 char** array = new char*[length + 1];
78 array[length] = 0;
79 for (jsize i = 0; i < length; ++i) {
80 ScopedLocalRef<jstring> javaEntry(env, reinterpret_cast<jstring>(env->GetObjectArrayElement(javaArray, i)));
81 // We need to pass these strings to const-unfriendly code.
82 char* entry = const_cast<char*>(env->GetStringUTFChars(javaEntry.get(), NULL));
83 array[i] = entry;
84 }
85
86 return array;
87 }
88
89 /** Frees a char** which was converted from a Java String[]. */
freeStrings(JNIEnv * env,jobjectArray javaArray,char ** array)90 void freeStrings(JNIEnv* env, jobjectArray javaArray, char** array) {
91 if (javaArray == NULL) {
92 return;
93 }
94
95 jsize length = env->GetArrayLength(javaArray);
96 for (jsize i = 0; i < length; ++i) {
97 ScopedLocalRef<jstring> javaEntry(env, reinterpret_cast<jstring>(env->GetObjectArrayElement(javaArray, i)));
98 env->ReleaseStringUTFChars(javaEntry.get(), array[i]);
99 }
100
101 delete[] array;
102 }
103