base/android/jni_array.cc

   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_array.h"
   6
   7 #include "base/android/jni_android.h"
   8 #include "base/android/jni_string.h"
   9 #include "base/logging.h"
  10
  11 namespace base {
  12 namespace android {
  13 namespace {
  14
  15 // As |GetArrayLength| makes no guarantees about the returned value (e.g., it
  16 // may be -1 if |array| is not a valid Java array), provide a safe wrapper
  17 // that always returns a valid, non-negative size.
  18 template <typename JavaArrayType>
  19 size_t SafeGetArrayLength(JNIEnv* env, JavaArrayType jarray) {
  20   DCHECK(jarray);
  21   jsize length = env->GetArrayLength(jarray);
  22   DCHECK_GE(length, 0) << "Invalid array length: " << length;
  23   return static_cast<size_t>(std::max(0, length));
  24 }
  25
  26 }  // namespace
  27
  28 ScopedJavaLocalRef<jbyteArray> ToJavaByteArray(
  29     JNIEnv* env, const uint8* bytes, size_t len) {
  30   jbyteArray byte_array = env->NewByteArray(len);
  31   CheckException(env);
  32   DCHECK(byte_array);
  33
  34   env->SetByteArrayRegion(
  35       byte_array, 0, len, reinterpret_cast<const jbyte*>(bytes));
  36   CheckException(env);
  37
  38   return ScopedJavaLocalRef<jbyteArray>(env, byte_array);
  39 }
  40
  41 ScopedJavaLocalRef<jintArray> ToJavaIntArray(
  42     JNIEnv* env, const int* ints, size_t len) {
  43   jintArray int_array = env->NewIntArray(len);
  44   CheckException(env);
  45   DCHECK(int_array);
  46
  47   env->SetIntArrayRegion(
  48       int_array, 0, len, reinterpret_cast<const jint*>(ints));
  49   CheckException(env);
  50
  51   return ScopedJavaLocalRef<jintArray>(env, int_array);
  52 }
  53
  54 ScopedJavaLocalRef<jintArray> ToJavaIntArray(
  55     JNIEnv* env, const std::vector<int>& ints) {
  56   return ToJavaIntArray(env, ints.begin(), ints.size());
  57 }
  58
  59 ScopedJavaLocalRef<jlongArray> ToJavaLongArray(
  60     JNIEnv* env, const int64* longs, size_t len) {
  61   jlongArray long_array = env->NewLongArray(len);
  62   CheckException(env);
  63   DCHECK(long_array);
  64
  65   env->SetLongArrayRegion(
  66       long_array, 0, len, reinterpret_cast<const jlong*>(longs));
  67   CheckException(env);
  68
  69   return ScopedJavaLocalRef<jlongArray>(env, long_array);
  70 }
  71
  72 // Returns a new Java long array converted from the given int64 array.
  73 BASE_EXPORT ScopedJavaLocalRef<jlongArray> ToJavaLongArray(
  74     JNIEnv* env, const std::vector<int64>& longs) {
  75   return ToJavaLongArray(env, longs.begin(), longs.size());
  76 }
  77
  78 ScopedJavaLocalRef<jobjectArray> ToJavaArrayOfByteArray(
  79     JNIEnv* env, const std::vector<std::string>& v) {
  80   ScopedJavaLocalRef<jclass> byte_array_clazz = GetClass(env, "[B");
  81   jobjectArray joa = env->NewObjectArray(v.size(),
  82                                          byte_array_clazz.obj(), NULL);
  83   CheckException(env);
  84
  85   for (size_t i = 0; i < v.size(); ++i) {
  86     ScopedJavaLocalRef<jbyteArray> byte_array = ToJavaByteArray(env,
  87         reinterpret_cast<const uint8*>(v[i].data()), v[i].length());
  88     env->SetObjectArrayElement(joa, i, byte_array.obj());
  89   }
  90   return ScopedJavaLocalRef<jobjectArray>(env, joa);
  91 }
  92
  93 ScopedJavaLocalRef<jobjectArray> ToJavaArrayOfStrings(
  94     JNIEnv* env, const std::vector<std::string>& v) {
  95   ScopedJavaLocalRef<jclass> string_clazz = GetClass(env, "java/lang/String");
  96   jobjectArray joa = env->NewObjectArray(v.size(), string_clazz.obj(), NULL);
  97   CheckException(env);
  98
  99   for (size_t i = 0; i < v.size(); ++i) {
 100     ScopedJavaLocalRef<jstring> item = ConvertUTF8ToJavaString(env, v[i]);
 101     env->SetObjectArrayElement(joa, i, item.obj());
 102   }
 103   return ScopedJavaLocalRef<jobjectArray>(env, joa);
 104 }
 105
 106 ScopedJavaLocalRef<jobjectArray> ToJavaArrayOfStrings(
 107     JNIEnv* env, const std::vector<string16>& v) {
 108   ScopedJavaLocalRef<jclass> string_clazz = GetClass(env, "java/lang/String");
 109   jobjectArray joa = env->NewObjectArray(v.size(), string_clazz.obj(), NULL);
 110   CheckException(env);
 111
 112   for (size_t i = 0; i < v.size(); ++i) {
 113     ScopedJavaLocalRef<jstring> item = ConvertUTF16ToJavaString(env, v[i]);
 114     env->SetObjectArrayElement(joa, i, item.obj());
 115   }
 116   return ScopedJavaLocalRef<jobjectArray>(env, joa);
 117 }
 118
 119 void AppendJavaStringArrayToStringVector(JNIEnv* env,
 120                                          jobjectArray array,
 121                                          std::vector<string16>* out) {
 122   DCHECK(out);
 123   if (!array)
 124     return;
 125   size_t len = SafeGetArrayLength(env, array);
 126   size_t back = out->size();
 127   out->resize(back + len);
 128   for (size_t i = 0; i < len; ++i) {
 129     ScopedJavaLocalRef<jstring> str(env,
 130         static_cast<jstring>(env->GetObjectArrayElement(array, i)));
 131     ConvertJavaStringToUTF16(env, str.obj(), &((*out)[back + i]));
 132   }
 133 }
 134
 135 void AppendJavaStringArrayToStringVector(JNIEnv* env,
 136                                          jobjectArray array,
 137                                          std::vector<std::string>* out) {
 138   DCHECK(out);
 139   if (!array)
 140     return;
 141   size_t len = SafeGetArrayLength(env, array);
 142   size_t back = out->size();
 143   out->resize(back + len);
 144   for (size_t i = 0; i < len; ++i) {
 145     ScopedJavaLocalRef<jstring> str(env,
 146         static_cast<jstring>(env->GetObjectArrayElement(array, i)));
 147     ConvertJavaStringToUTF8(env, str.obj(), &((*out)[back + i]));
 148   }
 149 }
 150
 151 void AppendJavaByteArrayToByteVector(JNIEnv* env,
 152                                      jbyteArray byte_array,
 153                                      std::vector<uint8>* out) {
 154   DCHECK(out);
 155   if (!byte_array)
 156     return;
 157   size_t len = SafeGetArrayLength(env, byte_array);
 158   if (!len)
 159     return;
 160   size_t back = out->size();
 161   out->resize(back + len);
 162   env->GetByteArrayRegion(byte_array, 0, len,
 163                           reinterpret_cast<int8*>(&(*out)[back]));
 164 }
 165
 166 void JavaByteArrayToByteVector(JNIEnv* env,
 167                                jbyteArray byte_array,
 168                                std::vector<uint8>* out) {
 169   DCHECK(out);
 170   DCHECK(byte_array);
 171   out->clear();
 172   AppendJavaByteArrayToByteVector(env, byte_array, out);
 173 }
 174
 175 void JavaIntArrayToIntVector(JNIEnv* env,
 176                              jintArray int_array,
 177                              std::vector<int>* out) {
 178   DCHECK(out);
 179   size_t len = SafeGetArrayLength(env, int_array);
 180   out->resize(len);
 181   if (!len)
 182     return;
 183   // TODO(jdduke): Use |out->data()| for pointer access after switch to libc++,
 184   // both here and in the other conversion routines. See crbug.com/427718.
 185   env->GetIntArrayRegion(int_array, 0, len, &(*out)[0]);
 186 }
 187
 188 void JavaLongArrayToLongVector(JNIEnv* env,
 189                                jlongArray long_array,
 190                                std::vector<jlong>* out) {
 191   DCHECK(out);
 192   size_t len = SafeGetArrayLength(env, long_array);
 193   out->resize(len);
 194   if (!len)
 195     return;
 196   env->GetLongArrayRegion(long_array, 0, len, &(*out)[0]);
 197 }
 198
 199 void JavaFloatArrayToFloatVector(JNIEnv* env,
 200                                  jfloatArray float_array,
 201                                  std::vector<float>* out) {
 202   DCHECK(out);
 203   size_t len = SafeGetArrayLength(env, float_array);
 204   out->resize(len);
 205   if (!len)
 206     return;
 207   env->GetFloatArrayRegion(float_array, 0, len, &(*out)[0]);
 208 }
 209
 210 void JavaArrayOfByteArrayToStringVector(
 211     JNIEnv* env,
 212     jobjectArray array,
 213     std::vector<std::string>* out) {
 214   DCHECK(out);
 215   size_t len = SafeGetArrayLength(env, array);
 216   out->resize(len);
 217   for (size_t i = 0; i < len; ++i) {
 218     ScopedJavaLocalRef<jbyteArray> bytes_array(
 219         env, static_cast<jbyteArray>(
 220             env->GetObjectArrayElement(array, i)));
 221     jsize bytes_len = env->GetArrayLength(bytes_array.obj());
 222     jbyte* bytes = env->GetByteArrayElements(bytes_array.obj(), NULL);
 223     (*out)[i].assign(reinterpret_cast<const char*>(bytes), bytes_len);
 224     env->ReleaseByteArrayElements(bytes_array.obj(), bytes, JNI_ABORT);
 225   }
 226 }
 227
 228 }  // namespace android
 229 }  // namespace base