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; 25 VectorCounter(const std::vector<std::string>& strings) : strings(strings) {} 26 size_t operator()() { 27 return strings.size(); 28 } 29 }; 30 struct VectorGetter { 31 const std::vector<std::string>& strings; 32 VectorGetter(const std::vector<std::string>& strings) : strings(strings) {} 33 const char* operator()(size_t i) { 34 return strings[i].c_str(); 35 } 36 }; 37 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; 46 ArrayCounter(const char* const* strings) : strings(strings) {} 47 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; 58 ArrayGetter(const char* const* strings) : strings(strings) {} 59 const char* operator()(size_t i) { 60 return strings[i]; 61 } 62 }; 63 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**. */ 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[]. */ 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
