Android NDK项目：java.lang.UnsatisfiedLinkError:dalvik.system.PathClassLoader

我是NDK的新手

我想在我的标准java Android工作室项目中添加一些C++代码。 我所做的：

在主文件夹下添加cpp文件夹

在我的cpp文件夹中添加myccplib.cpp和myccplib.h

在Gradle（模块）中添加以下内容：

myccplib.cpp中的代码：

#include "myccplib.h"


 #include <jni.h>
 #include <string>

 extern "C" JNIEXPORT jstring JNICALL


 Java_com_example_tof_MainActivity_stringFromJNI( JNIEnv *env, jobject /* this */) {
     std::string hello = "Hello, World!";
     return env->NewStringUTF(hello.c_str());
 }

我的CMakeLists.txt文件：

cmake_minimum_required(VERSION 3.4.1)

# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.

add_library( # Sets the name of the library.
             native-lib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             native-lib.cpp )

# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.

find_library( # Sets the name of the path variable.
              log-lib

              # Specifies the name of the NDK library that
              # you want CMake to locate.
              log )

# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} )

问题：我遇到了车祸：

2020-10-14 19:02:45.465 25918-25918/com.example.tof E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.tof, PID: 25918
java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader[DexPathList[[zip file "/data/app/com.example.tof-t8Csh416BSdO6UBfZv0mOw==/base.apk"],nativeLibraryDirectories=[/data/app/com.example.tof-t8Csh416BSdO6UBfZv0mOw==/lib/arm64, /system/lib64, /product/lib64]]] couldn't find "libmyccplib.so"
    at java.lang.Runtime.loadLibrary0(Runtime.java:1067)
    at java.lang.Runtime.loadLibrary0(Runtime.java:1007)
    at java.lang.System.loadLibrary(System.java:1667)
    at com.example.tof.MainActivity.<clinit>(MainActivity.java:37)

2020-10-1419:02:45.465 25918-25918/com.example.tof E/AndroidRuntime:致命异常：main
进程：com.example.tof，PID:25918
java.lang.UnsatifiedLinkError:dalvik.system.PathClassLoader[DexPathList[[zip文件”/data/app/com.example.tof-t8Csh416BSdO6UBfZv0mOw===/base.apk”]，NativeLibraryDirectory=[/data/app/com.example.tof-t8Csh416BSdO6UBfZv0mOw==/lib/arm64，/system/lib64，/product/lib64]]找不到“libmyccplib.so”
位于java.lang.Runtime.loadLibrary0（Runtime.java:1067）
位于java.lang.Runtime.loadLibrary0（Runtime.java:1007）
位于java.lang.System.loadLibrary（System.java:1667）
位于com.example.tof.MainActivity。（MainActivity.java:37）

我使用安卓4.0

谁能告诉我我错过了什么

---

谢谢

你给我们看的代码似乎与stacktrace不匹配。stacktrace说找不到

libmyccplib.so

，这表明您在

loadLibrary

调用中错误地包含了

“lib”

前缀（即您实际上正在执行

System.loadLibrary（“libmyccplib”）；

），您能共享CMakeLists.txt的内容吗？确保System.loadLibrary中使用的库名称与CMakeLists.txt中target_link_库中指定的名称匹配。如果是您的第一个项目，您可以使用Android Studio的“Native C++”向导项目模板，而不是手动添加所有内容，因此您可以将其用作学习基础知识的参考。@PerracoLabs谢谢！我没有任何CMakeLists.txt:）我知道我应该把它放在cpp文件夹中。但是我应该在这个文件中写什么呢？顺便说一句，迈克尔我更正了坠机日志；我没有粘贴正确的版本。谢谢@Regis_AG如果您没有任何本机构建脚本文件，那么无论是CMakeLists.txt还是旧的Android.mk，都不会编译本机二进制文件。CMakeLists.txt指示编译和生成的内容。我建议使用“本机C++向导模板”，因此文件->新项目->本机C++抱歉，实际上，我有一个，但它是空的。现在，我复制并粘贴了我项目中模板C++项目的CMAKLISTS.TXT文件的内容。我在CMakeLists.txt中重命名了文件名。但我仍然有这个问题。请注意，我的CMakeLists.txt文件的内容似乎不像模板项目中那样由Android Studio着色（所有字符均为灰色）；我不知道这是否会有影响。

cmake_minimum_required(VERSION 3.4.1)

# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.

add_library( # Sets the name of the library.
             native-lib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             native-lib.cpp )

# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.

find_library( # Sets the name of the path variable.
              log-lib

              # Specifies the name of the NDK library that
              # you want CMake to locate.
              log )

# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} )

2020-10-14 19:02:45.465 25918-25918/com.example.tof E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.tof, PID: 25918
java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader[DexPathList[[zip file "/data/app/com.example.tof-t8Csh416BSdO6UBfZv0mOw==/base.apk"],nativeLibraryDirectories=[/data/app/com.example.tof-t8Csh416BSdO6UBfZv0mOw==/lib/arm64, /system/lib64, /product/lib64]]] couldn't find "libmyccplib.so"
    at java.lang.Runtime.loadLibrary0(Runtime.java:1067)
    at java.lang.Runtime.loadLibrary0(Runtime.java:1007)
    at java.lang.System.loadLibrary(System.java:1667)
    at com.example.tof.MainActivity.<clinit>(MainActivity.java:37)