java - 调用 Android Java JNI GetDoubleField() 时发出 SIGABORT

问题描述

调用 GetDoubleField() 时，我得到一个 SIGABORT。

我写了一个小示例程序来显示这个问题......

MainActivity.java

package net.directionalsystems.jnitest;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

// Used to load the 'native-lib' library on application startup.
static {
    System.loadLibrary("native-lib");
}

private static final String TAG = "Mainactivity";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Example of a call to a native method
    TextView tv = findViewById(R.id.sample_text);

    JniComms jc = new JniComms();
    jc.latitude = 10;
    jc.logitude = 20;
    jc.txtLocation = "Hello";

    try {
        tv.setText(stringFromJNI(jc));
    }
    catch (Exception e)
    {

        Log.e(TAG, "onCreate: ", e);
    }
}

/**
 * A native method that is implemented by the 'native-lib' native library,
 * which is packaged with this application.
 */
public native String stringFromJNI(JniComms jc);

}

JniComms.java

package net.directionalsystems.jnitest;

import java.util.ArrayList;

public class JniComms
{
    public double latitude;
    public double logitude;
    public String txtLocation;
    //public ArrayList<BleStatus> bleStatusArray;

}

本机 lib.cpp

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

extern "C" JNIEXPORT jstring JNICALL
Java_net_directionalsystems_jnitest_MainActivity_stringFromJNI(
        JNIEnv *env,
        jobject jo,
        jobject jc)
        {

            jclass jcClass = env->GetObjectClass(jc);
            jfieldID iId = env->GetFieldID(jcClass, "latitude", "D");

            // Executing the next line causes SIGABORT
            jdouble latitude = env->GetDoubleField(jcClass, iId);

            std::string hello = "Hello world";
    return env->NewStringUTF(hello.c_str());
}

build.gradle 文件如下...

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.2"
    defaultConfig {
        applicationId "net.directionalsystems.jnitest"
        minSdkVersion 23
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                cppFlags ""
            }
        }
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
        customDebugType {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
            debuggable true
        }
    }
    externalNativeBuild {
        cmake {
            path "src/main/cpp/CMakeLists.txt"
            version "3.10.2"
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.0.2'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
}

这一定是我正在做的简单而愚蠢的事情。

我想调试 NDK 代码，但我得到的只是显示的 jni.h 文件，无法进入 JNI 代码本身。拥有这种能力可能会让我知道哪里出了问题。

非常感谢您的帮助。

最好的问候，杰基

标签： javaandroidjava-native-interface

java - 调用 Android Java JNI GetDoubleField() 时发出 SIGABORT

问题描述

解决方案

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