1/*
2 * Copyright (C) 2010 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// #define LOG_NDEBUG 0
18
19#define LOG_TAG "MtpDeviceJNI"
20#include "utils/Log.h"
21
22#include <stdio.h>
23#include <assert.h>
24#include <limits.h>
25#include <unistd.h>
26#include <fcntl.h>
27
28#include "jni.h"
29#include "JNIHelp.h"
30#include "android_runtime/AndroidRuntime.h"
31#include "android_runtime/Log.h"
32#include "private/android_filesystem_config.h"
33
34#include "MtpTypes.h"
35#include "MtpDevice.h"
36#include "MtpDeviceInfo.h"
37#include "MtpStorageInfo.h"
38#include "MtpObjectInfo.h"
39
40using namespace android;
41
42// ----------------------------------------------------------------------------
43
44static jfieldID field_context;
45
46jclass clazz_deviceInfo;
47jclass clazz_storageInfo;
48jclass clazz_objectInfo;
49
50jmethodID constructor_deviceInfo;
51jmethodID constructor_storageInfo;
52jmethodID constructor_objectInfo;
53
54// MtpDeviceInfo fields
55static jfieldID field_deviceInfo_manufacturer;
56static jfieldID field_deviceInfo_model;
57static jfieldID field_deviceInfo_version;
58static jfieldID field_deviceInfo_serialNumber;
59
60// MtpStorageInfo fields
61static jfieldID field_storageInfo_storageId;
62static jfieldID field_storageInfo_maxCapacity;
63static jfieldID field_storageInfo_freeSpace;
64static jfieldID field_storageInfo_description;
65static jfieldID field_storageInfo_volumeIdentifier;
66
67// MtpObjectInfo fields
68static jfieldID field_objectInfo_handle;
69static jfieldID field_objectInfo_storageId;
70static jfieldID field_objectInfo_format;
71static jfieldID field_objectInfo_protectionStatus;
72static jfieldID field_objectInfo_compressedSize;
73static jfieldID field_objectInfo_thumbFormat;
74static jfieldID field_objectInfo_thumbCompressedSize;
75static jfieldID field_objectInfo_thumbPixWidth;
76static jfieldID field_objectInfo_thumbPixHeight;
77static jfieldID field_objectInfo_imagePixWidth;
78static jfieldID field_objectInfo_imagePixHeight;
79static jfieldID field_objectInfo_imagePixDepth;
80static jfieldID field_objectInfo_parent;
81static jfieldID field_objectInfo_associationType;
82static jfieldID field_objectInfo_associationDesc;
83static jfieldID field_objectInfo_sequenceNumber;
84static jfieldID field_objectInfo_name;
85static jfieldID field_objectInfo_dateCreated;
86static jfieldID field_objectInfo_dateModified;
87static jfieldID field_objectInfo_keywords;
88
89MtpDevice* get_device_from_object(JNIEnv* env, jobject javaDevice)
90{
91    return (MtpDevice*)env->GetLongField(javaDevice, field_context);
92}
93
94static void checkAndClearExceptionFromCallback(JNIEnv* env, const char* methodName) {
95    if (env->ExceptionCheck()) {
96        ALOGE("An exception was thrown by callback '%s'.", methodName);
97        LOGE_EX(env);
98        env->ExceptionClear();
99    }
100}
101
102// ----------------------------------------------------------------------------
103
104static jboolean
105android_mtp_MtpDevice_open(JNIEnv *env, jobject thiz, jstring deviceName, jint fd)
106{
107    const char *deviceNameStr = env->GetStringUTFChars(deviceName, NULL);
108    if (deviceNameStr == NULL) {
109        return JNI_FALSE;
110    }
111
112    MtpDevice* device = MtpDevice::open(deviceNameStr, fd);
113    env->ReleaseStringUTFChars(deviceName, deviceNameStr);
114
115    if (device)
116        env->SetLongField(thiz, field_context,  (jlong)device);
117    return (jboolean)(device != NULL);
118}
119
120static void
121android_mtp_MtpDevice_close(JNIEnv *env, jobject thiz)
122{
123    MtpDevice* device = get_device_from_object(env, thiz);
124    if (device) {
125        device->close();
126        delete device;
127        env->SetLongField(thiz, field_context, 0);
128    }
129}
130
131static jobject
132android_mtp_MtpDevice_get_device_info(JNIEnv *env, jobject thiz)
133{
134    MtpDevice* device = get_device_from_object(env, thiz);
135    if (!device) {
136        ALOGD("android_mtp_MtpDevice_get_device_info device is null");
137        return NULL;
138    }
139    MtpDeviceInfo* deviceInfo = device->getDeviceInfo();
140    if (!deviceInfo) {
141        ALOGD("android_mtp_MtpDevice_get_device_info deviceInfo is null");
142        return NULL;
143    }
144    jobject info = env->NewObject(clazz_deviceInfo, constructor_deviceInfo);
145    if (info == NULL) {
146        ALOGE("Could not create a MtpDeviceInfo object");
147        delete deviceInfo;
148        return NULL;
149    }
150
151    if (deviceInfo->mManufacturer)
152        env->SetObjectField(info, field_deviceInfo_manufacturer,
153            env->NewStringUTF(deviceInfo->mManufacturer));
154    if (deviceInfo->mModel)
155        env->SetObjectField(info, field_deviceInfo_model,
156            env->NewStringUTF(deviceInfo->mModel));
157    if (deviceInfo->mVersion)
158        env->SetObjectField(info, field_deviceInfo_version,
159            env->NewStringUTF(deviceInfo->mVersion));
160    if (deviceInfo->mSerial)
161        env->SetObjectField(info, field_deviceInfo_serialNumber,
162            env->NewStringUTF(deviceInfo->mSerial));
163
164    delete deviceInfo;
165    return info;
166}
167
168static jintArray
169android_mtp_MtpDevice_get_storage_ids(JNIEnv *env, jobject thiz)
170{
171    MtpDevice* device = get_device_from_object(env, thiz);
172    if (!device)
173        return NULL;
174    MtpStorageIDList* storageIDs = device->getStorageIDs();
175    if (!storageIDs)
176        return NULL;
177
178    int length = storageIDs->size();
179    jintArray array = env->NewIntArray(length);
180    // FIXME is this cast safe?
181    env->SetIntArrayRegion(array, 0, length, (const jint *)storageIDs->array());
182
183    delete storageIDs;
184    return array;
185}
186
187static jobject
188android_mtp_MtpDevice_get_storage_info(JNIEnv *env, jobject thiz, jint storageID)
189{
190    MtpDevice* device = get_device_from_object(env, thiz);
191    if (!device)
192        return NULL;
193    MtpStorageInfo* storageInfo = device->getStorageInfo(storageID);
194    if (!storageInfo)
195        return NULL;
196
197    jobject info = env->NewObject(clazz_storageInfo, constructor_storageInfo);
198    if (info == NULL) {
199        ALOGE("Could not create a MtpStorageInfo object");
200        delete storageInfo;
201        return NULL;
202    }
203
204    if (storageInfo->mStorageID)
205        env->SetIntField(info, field_storageInfo_storageId, storageInfo->mStorageID);
206    if (storageInfo->mMaxCapacity)
207        env->SetLongField(info, field_storageInfo_maxCapacity, storageInfo->mMaxCapacity);
208    if (storageInfo->mFreeSpaceBytes)
209        env->SetLongField(info, field_storageInfo_freeSpace, storageInfo->mFreeSpaceBytes);
210    if (storageInfo->mStorageDescription)
211        env->SetObjectField(info, field_storageInfo_description,
212            env->NewStringUTF(storageInfo->mStorageDescription));
213    if (storageInfo->mVolumeIdentifier)
214        env->SetObjectField(info, field_storageInfo_volumeIdentifier,
215            env->NewStringUTF(storageInfo->mVolumeIdentifier));
216
217    delete storageInfo;
218    return info;
219}
220
221static jintArray
222android_mtp_MtpDevice_get_object_handles(JNIEnv *env, jobject thiz,
223        jint storageID, jint format, jint objectID)
224{
225    MtpDevice* device = get_device_from_object(env, thiz);
226    if (!device)
227        return NULL;
228    MtpObjectHandleList* handles = device->getObjectHandles(storageID, format, objectID);
229    if (!handles)
230        return NULL;
231
232    int length = handles->size();
233    jintArray array = env->NewIntArray(length);
234    // FIXME is this cast safe?
235    env->SetIntArrayRegion(array, 0, length, (const jint *)handles->array());
236
237    delete handles;
238    return array;
239}
240
241static jobject
242android_mtp_MtpDevice_get_object_info(JNIEnv *env, jobject thiz, jint objectID)
243{
244    MtpDevice* device = get_device_from_object(env, thiz);
245    if (!device)
246        return NULL;
247    MtpObjectInfo* objectInfo = device->getObjectInfo(objectID);
248    if (!objectInfo)
249        return NULL;
250    jobject info = env->NewObject(clazz_objectInfo, constructor_objectInfo);
251    if (info == NULL) {
252        ALOGE("Could not create a MtpObjectInfo object");
253        delete objectInfo;
254        return NULL;
255    }
256
257    if (objectInfo->mHandle)
258        env->SetIntField(info, field_objectInfo_handle, objectInfo->mHandle);
259    if (objectInfo->mStorageID)
260        env->SetIntField(info, field_objectInfo_storageId, objectInfo->mStorageID);
261    if (objectInfo->mFormat)
262        env->SetIntField(info, field_objectInfo_format, objectInfo->mFormat);
263    if (objectInfo->mProtectionStatus)
264        env->SetIntField(info, field_objectInfo_protectionStatus, objectInfo->mProtectionStatus);
265    if (objectInfo->mCompressedSize)
266        env->SetIntField(info, field_objectInfo_compressedSize, objectInfo->mCompressedSize);
267    if (objectInfo->mThumbFormat)
268        env->SetIntField(info, field_objectInfo_thumbFormat, objectInfo->mThumbFormat);
269    if (objectInfo->mThumbCompressedSize)
270        env->SetIntField(info, field_objectInfo_thumbCompressedSize, objectInfo->mThumbCompressedSize);
271    if (objectInfo->mThumbPixWidth)
272        env->SetIntField(info, field_objectInfo_thumbPixWidth, objectInfo->mThumbPixWidth);
273    if (objectInfo->mThumbPixHeight)
274        env->SetIntField(info, field_objectInfo_thumbPixHeight, objectInfo->mThumbPixHeight);
275    if (objectInfo->mImagePixWidth)
276        env->SetIntField(info, field_objectInfo_imagePixWidth, objectInfo->mImagePixWidth);
277    if (objectInfo->mImagePixHeight)
278        env->SetIntField(info, field_objectInfo_imagePixHeight, objectInfo->mImagePixHeight);
279    if (objectInfo->mImagePixDepth)
280        env->SetIntField(info, field_objectInfo_imagePixDepth, objectInfo->mImagePixDepth);
281    if (objectInfo->mParent)
282        env->SetIntField(info, field_objectInfo_parent, objectInfo->mParent);
283    if (objectInfo->mAssociationType)
284        env->SetIntField(info, field_objectInfo_associationType, objectInfo->mAssociationType);
285    if (objectInfo->mAssociationDesc)
286        env->SetIntField(info, field_objectInfo_associationDesc, objectInfo->mAssociationDesc);
287    if (objectInfo->mSequenceNumber)
288        env->SetIntField(info, field_objectInfo_sequenceNumber, objectInfo->mSequenceNumber);
289    if (objectInfo->mName)
290        env->SetObjectField(info, field_objectInfo_name, env->NewStringUTF(objectInfo->mName));
291    if (objectInfo->mDateCreated)
292        env->SetLongField(info, field_objectInfo_dateCreated, objectInfo->mDateCreated * 1000LL);
293    if (objectInfo->mDateModified)
294        env->SetLongField(info, field_objectInfo_dateModified, objectInfo->mDateModified * 1000LL);
295    if (objectInfo->mKeywords)
296        env->SetObjectField(info, field_objectInfo_keywords,
297            env->NewStringUTF(objectInfo->mKeywords));
298
299    delete objectInfo;
300    return info;
301}
302
303struct get_object_callback_data {
304    JNIEnv *env;
305    jbyteArray array;
306};
307
308static bool get_object_callback(void* data, int offset, int length, void* clientData)
309{
310    get_object_callback_data* cbData = (get_object_callback_data *)clientData;
311    cbData->env->SetByteArrayRegion(cbData->array, offset, length, (jbyte *)data);
312    return true;
313}
314
315static jbyteArray
316android_mtp_MtpDevice_get_object(JNIEnv *env, jobject thiz, jint objectID, jint objectSize)
317{
318    MtpDevice* device = get_device_from_object(env, thiz);
319    if (!device)
320        return NULL;
321
322    jbyteArray array = env->NewByteArray(objectSize);
323    if (!array) {
324        jniThrowException(env, "java/lang/OutOfMemoryError", NULL);
325        return NULL;
326    }
327
328    get_object_callback_data data;
329    data.env = env;
330    data.array = array;
331
332    if (device->readObject(objectID, get_object_callback, objectSize, &data))
333        return array;
334    return NULL;
335}
336
337static jbyteArray
338android_mtp_MtpDevice_get_thumbnail(JNIEnv *env, jobject thiz, jint objectID)
339{
340    MtpDevice* device = get_device_from_object(env, thiz);
341    if (!device)
342        return NULL;
343
344    int length;
345    void* thumbnail = device->getThumbnail(objectID, length);
346    if (! thumbnail)
347        return NULL;
348    jbyteArray array = env->NewByteArray(length);
349    env->SetByteArrayRegion(array, 0, length, (const jbyte *)thumbnail);
350
351    free(thumbnail);
352    return array;
353}
354
355static jboolean
356android_mtp_MtpDevice_delete_object(JNIEnv *env, jobject thiz, jint object_id)
357{
358    MtpDevice* device = get_device_from_object(env, thiz);
359    if (device && device->deleteObject(object_id)) {
360        return JNI_TRUE;
361    } else {
362        return JNI_FALSE;
363    }
364}
365
366static jlong
367android_mtp_MtpDevice_get_parent(JNIEnv *env, jobject thiz, jint object_id)
368{
369    MtpDevice* device = get_device_from_object(env, thiz);
370    if (device)
371        return (jlong)device->getParent(object_id);
372    else
373        return -1;
374}
375
376static jlong
377android_mtp_MtpDevice_get_storage_id(JNIEnv *env, jobject thiz, jint object_id)
378{
379    MtpDevice* device = get_device_from_object(env, thiz);
380    if (device)
381        return (jlong)device->getStorageID(object_id);
382    else
383        return -1;
384}
385
386static jboolean
387android_mtp_MtpDevice_import_file(JNIEnv *env, jobject thiz, jint object_id, jstring dest_path)
388{
389    MtpDevice* device = get_device_from_object(env, thiz);
390    if (device) {
391        const char *destPathStr = env->GetStringUTFChars(dest_path, NULL);
392        if (destPathStr == NULL) {
393            return JNI_FALSE;
394        }
395
396        jboolean result = device->readObject(object_id, destPathStr, AID_SDCARD_RW, 0664);
397        env->ReleaseStringUTFChars(dest_path, destPathStr);
398        return result;
399    }
400
401    return JNI_FALSE;
402}
403
404// ----------------------------------------------------------------------------
405
406static JNINativeMethod gMethods[] = {
407    {"native_open",             "(Ljava/lang/String;I)Z",
408                                        (void *)android_mtp_MtpDevice_open},
409    {"native_close",            "()V",  (void *)android_mtp_MtpDevice_close},
410    {"native_get_device_info",  "()Landroid/mtp/MtpDeviceInfo;",
411                                        (void *)android_mtp_MtpDevice_get_device_info},
412    {"native_get_storage_ids",  "()[I", (void *)android_mtp_MtpDevice_get_storage_ids},
413    {"native_get_storage_info", "(I)Landroid/mtp/MtpStorageInfo;",
414                                        (void *)android_mtp_MtpDevice_get_storage_info},
415    {"native_get_object_handles","(III)[I",
416                                        (void *)android_mtp_MtpDevice_get_object_handles},
417    {"native_get_object_info",  "(I)Landroid/mtp/MtpObjectInfo;",
418                                        (void *)android_mtp_MtpDevice_get_object_info},
419    {"native_get_object",       "(II)[B",(void *)android_mtp_MtpDevice_get_object},
420    {"native_get_thumbnail",    "(I)[B",(void *)android_mtp_MtpDevice_get_thumbnail},
421    {"native_delete_object",    "(I)Z", (void *)android_mtp_MtpDevice_delete_object},
422    {"native_get_parent",       "(I)J", (void *)android_mtp_MtpDevice_get_parent},
423    {"native_get_storage_id",   "(I)J", (void *)android_mtp_MtpDevice_get_storage_id},
424    {"native_import_file",     "(ILjava/lang/String;)Z",
425                                        (void *)android_mtp_MtpDevice_import_file},
426};
427
428static const char* const kClassPathName = "android/mtp/MtpDevice";
429
430int register_android_mtp_MtpDevice(JNIEnv *env)
431{
432    jclass clazz;
433
434    ALOGD("register_android_mtp_MtpDevice\n");
435
436    clazz = env->FindClass("android/mtp/MtpDeviceInfo");
437    if (clazz == NULL) {
438        ALOGE("Can't find android/mtp/MtpDeviceInfo");
439        return -1;
440    }
441    constructor_deviceInfo = env->GetMethodID(clazz, "<init>", "()V");
442    if (constructor_deviceInfo == NULL) {
443        ALOGE("Can't find android/mtp/MtpDeviceInfo constructor");
444        return -1;
445    }
446    field_deviceInfo_manufacturer = env->GetFieldID(clazz, "mManufacturer", "Ljava/lang/String;");
447    if (field_deviceInfo_manufacturer == NULL) {
448        ALOGE("Can't find MtpDeviceInfo.mManufacturer");
449        return -1;
450    }
451    field_deviceInfo_model = env->GetFieldID(clazz, "mModel", "Ljava/lang/String;");
452    if (field_deviceInfo_model == NULL) {
453        ALOGE("Can't find MtpDeviceInfo.mModel");
454        return -1;
455    }
456    field_deviceInfo_version = env->GetFieldID(clazz, "mVersion", "Ljava/lang/String;");
457    if (field_deviceInfo_version == NULL) {
458        ALOGE("Can't find MtpDeviceInfo.mVersion");
459        return -1;
460    }
461    field_deviceInfo_serialNumber = env->GetFieldID(clazz, "mSerialNumber", "Ljava/lang/String;");
462    if (field_deviceInfo_serialNumber == NULL) {
463        ALOGE("Can't find MtpDeviceInfo.mSerialNumber");
464        return -1;
465    }
466    clazz_deviceInfo = (jclass)env->NewGlobalRef(clazz);
467
468    clazz = env->FindClass("android/mtp/MtpStorageInfo");
469    if (clazz == NULL) {
470        ALOGE("Can't find android/mtp/MtpStorageInfo");
471        return -1;
472    }
473    constructor_storageInfo = env->GetMethodID(clazz, "<init>", "()V");
474    if (constructor_storageInfo == NULL) {
475        ALOGE("Can't find android/mtp/MtpStorageInfo constructor");
476        return -1;
477    }
478    field_storageInfo_storageId = env->GetFieldID(clazz, "mStorageId", "I");
479    if (field_storageInfo_storageId == NULL) {
480        ALOGE("Can't find MtpStorageInfo.mStorageId");
481        return -1;
482    }
483    field_storageInfo_maxCapacity = env->GetFieldID(clazz, "mMaxCapacity", "J");
484    if (field_storageInfo_maxCapacity == NULL) {
485        ALOGE("Can't find MtpStorageInfo.mMaxCapacity");
486        return -1;
487    }
488    field_storageInfo_freeSpace = env->GetFieldID(clazz, "mFreeSpace", "J");
489    if (field_storageInfo_freeSpace == NULL) {
490        ALOGE("Can't find MtpStorageInfo.mFreeSpace");
491        return -1;
492    }
493    field_storageInfo_description = env->GetFieldID(clazz, "mDescription", "Ljava/lang/String;");
494    if (field_storageInfo_description == NULL) {
495        ALOGE("Can't find MtpStorageInfo.mDescription");
496        return -1;
497    }
498    field_storageInfo_volumeIdentifier = env->GetFieldID(clazz, "mVolumeIdentifier", "Ljava/lang/String;");
499    if (field_storageInfo_volumeIdentifier == NULL) {
500        ALOGE("Can't find MtpStorageInfo.mVolumeIdentifier");
501        return -1;
502    }
503    clazz_storageInfo = (jclass)env->NewGlobalRef(clazz);
504
505    clazz = env->FindClass("android/mtp/MtpObjectInfo");
506    if (clazz == NULL) {
507        ALOGE("Can't find android/mtp/MtpObjectInfo");
508        return -1;
509    }
510    constructor_objectInfo = env->GetMethodID(clazz, "<init>", "()V");
511    if (constructor_objectInfo == NULL) {
512        ALOGE("Can't find android/mtp/MtpObjectInfo constructor");
513        return -1;
514    }
515    field_objectInfo_handle = env->GetFieldID(clazz, "mHandle", "I");
516    if (field_objectInfo_handle == NULL) {
517        ALOGE("Can't find MtpObjectInfo.mHandle");
518        return -1;
519    }
520    field_objectInfo_storageId = env->GetFieldID(clazz, "mStorageId", "I");
521    if (field_objectInfo_storageId == NULL) {
522        ALOGE("Can't find MtpObjectInfo.mStorageId");
523        return -1;
524    }
525    field_objectInfo_format = env->GetFieldID(clazz, "mFormat", "I");
526    if (field_objectInfo_format == NULL) {
527        ALOGE("Can't find MtpObjectInfo.mFormat");
528        return -1;
529    }
530    field_objectInfo_protectionStatus = env->GetFieldID(clazz, "mProtectionStatus", "I");
531    if (field_objectInfo_protectionStatus == NULL) {
532        ALOGE("Can't find MtpObjectInfo.mProtectionStatus");
533        return -1;
534    }
535    field_objectInfo_compressedSize = env->GetFieldID(clazz, "mCompressedSize", "I");
536    if (field_objectInfo_compressedSize == NULL) {
537        ALOGE("Can't find MtpObjectInfo.mCompressedSize");
538        return -1;
539    }
540    field_objectInfo_thumbFormat = env->GetFieldID(clazz, "mThumbFormat", "I");
541    if (field_objectInfo_thumbFormat == NULL) {
542        ALOGE("Can't find MtpObjectInfo.mThumbFormat");
543        return -1;
544    }
545    field_objectInfo_thumbCompressedSize = env->GetFieldID(clazz, "mThumbCompressedSize", "I");
546    if (field_objectInfo_thumbCompressedSize == NULL) {
547        ALOGE("Can't find MtpObjectInfo.mThumbCompressedSize");
548        return -1;
549    }
550    field_objectInfo_thumbPixWidth = env->GetFieldID(clazz, "mThumbPixWidth", "I");
551    if (field_objectInfo_thumbPixWidth == NULL) {
552        ALOGE("Can't find MtpObjectInfo.mThumbPixWidth");
553        return -1;
554    }
555    field_objectInfo_thumbPixHeight = env->GetFieldID(clazz, "mThumbPixHeight", "I");
556    if (field_objectInfo_thumbPixHeight == NULL) {
557        ALOGE("Can't find MtpObjectInfo.mThumbPixHeight");
558        return -1;
559    }
560    field_objectInfo_imagePixWidth = env->GetFieldID(clazz, "mImagePixWidth", "I");
561    if (field_objectInfo_imagePixWidth == NULL) {
562        ALOGE("Can't find MtpObjectInfo.mImagePixWidth");
563        return -1;
564    }
565    field_objectInfo_imagePixHeight = env->GetFieldID(clazz, "mImagePixHeight", "I");
566    if (field_objectInfo_imagePixHeight == NULL) {
567        ALOGE("Can't find MtpObjectInfo.mImagePixHeight");
568        return -1;
569    }
570    field_objectInfo_imagePixDepth = env->GetFieldID(clazz, "mImagePixDepth", "I");
571    if (field_objectInfo_imagePixDepth == NULL) {
572        ALOGE("Can't find MtpObjectInfo.mImagePixDepth");
573        return -1;
574    }
575    field_objectInfo_parent = env->GetFieldID(clazz, "mParent", "I");
576    if (field_objectInfo_parent == NULL) {
577        ALOGE("Can't find MtpObjectInfo.mParent");
578        return -1;
579    }
580    field_objectInfo_associationType = env->GetFieldID(clazz, "mAssociationType", "I");
581    if (field_objectInfo_associationType == NULL) {
582        ALOGE("Can't find MtpObjectInfo.mAssociationType");
583        return -1;
584    }
585    field_objectInfo_associationDesc = env->GetFieldID(clazz, "mAssociationDesc", "I");
586    if (field_objectInfo_associationDesc == NULL) {
587        ALOGE("Can't find MtpObjectInfo.mAssociationDesc");
588        return -1;
589    }
590    field_objectInfo_sequenceNumber = env->GetFieldID(clazz, "mSequenceNumber", "I");
591    if (field_objectInfo_sequenceNumber == NULL) {
592        ALOGE("Can't find MtpObjectInfo.mSequenceNumber");
593        return -1;
594    }
595    field_objectInfo_name = env->GetFieldID(clazz, "mName", "Ljava/lang/String;");
596    if (field_objectInfo_name == NULL) {
597        ALOGE("Can't find MtpObjectInfo.mName");
598        return -1;
599    }
600    field_objectInfo_dateCreated = env->GetFieldID(clazz, "mDateCreated", "J");
601    if (field_objectInfo_dateCreated == NULL) {
602        ALOGE("Can't find MtpObjectInfo.mDateCreated");
603        return -1;
604    }
605    field_objectInfo_dateModified = env->GetFieldID(clazz, "mDateModified", "J");
606    if (field_objectInfo_dateModified == NULL) {
607        ALOGE("Can't find MtpObjectInfo.mDateModified");
608        return -1;
609    }
610    field_objectInfo_keywords = env->GetFieldID(clazz, "mKeywords", "Ljava/lang/String;");
611    if (field_objectInfo_keywords == NULL) {
612        ALOGE("Can't find MtpObjectInfo.mKeywords");
613        return -1;
614    }
615    clazz_objectInfo = (jclass)env->NewGlobalRef(clazz);
616
617    clazz = env->FindClass("android/mtp/MtpDevice");
618    if (clazz == NULL) {
619        ALOGE("Can't find android/mtp/MtpDevice");
620        return -1;
621    }
622    field_context = env->GetFieldID(clazz, "mNativeContext", "J");
623    if (field_context == NULL) {
624        ALOGE("Can't find MtpDevice.mNativeContext");
625        return -1;
626    }
627
628    return AndroidRuntime::registerNativeMethods(env,
629                "android/mtp/MtpDevice", gMethods, NELEM(gMethods));
630}
631