在JNI C中检查android设备上是否安装了包

#include <jni.h>
#include <android/asset_manager_jni.h>
#include <android/log.h>
#include <sys/system_properties.h>

JNIEXPORT jboolean JNICALL
Java_com_example_example_MainActivity_isPackageInstalled(JNIEnv *env, jobject instance,
                                                         jobject assetManager) {
    AAssetManager *aAssetManager = AAssetManager_fromJava(env, assetManager);

    // 获取应用包名
    AAsset *manifestAsset = AAssetManager_open(aAssetManager, "AndroidManifest.xml", AASSET_MODE_BUFFER);
    off_t manifestSize = AAsset_getLength(manifestAsset);
    char *manifestData = (char *) malloc(manifestSize + 1);
    AAsset_read(manifestAsset, manifestData, manifestSize);
    manifestData[manifestSize] = '\0';

    const char *packageName = strstr(manifestData, "package=\"");
    if (packageName != NULL) {
        packageName += strlen("package=\"");
        char *end = strchr(packageName, '\"');
        if (end != NULL) {
            *end = '\0';
        }
    }

    AAsset_close(manifestAsset);
    free(manifestData);

    // 检查应用是否安装
    jclass packageManagerClass = (*env)->FindClass(env, "android/content/pm/PackageManager");
    jmethodID getPackageInfoMethod = (*env)->GetMethodID(env, packageManagerClass, "getPackageInfo",
                                                         "(Ljava/lang/String;I)Landroid/content/pm/PackageInfo;");
    jobject packageManager = (*env)->CallObjectMethod(env, instance, getPackageManagerMethod);
    jobject packageInfo = (*env)->CallObjectMethod(env, packageManager, getPackageInfoMethod,
                                                   (*env)->NewStringUTF(env, packageName),
                                                   GET_PACKAGE_INFO_FLAG_META_DATA);

    jboolean isInstalled = (packageInfo != NULL) ? JNI_TRUE : JNI_FALSE;

    return isInstalled;
}