</pre><p>注：假设是自己的myself.jar包，还要修改例如以下：</p><p>target/product/core_base.mk PRODUCT_BOOT_JARS := core:myself</p><p></p><p>功能：手机开机后要写个标志位。

已有实现。就是收到开机广播后，启动服务读取bp中的标志位（java代码须要等待ril准备好）。并把这个标志位写入到ap中（java代码调用c++）。

后来遇到的问题：实际应用中发现，接收开机广播等待的时间更长，须要提前写入ap时间。

解决方式：在init.rc文件中面启动c++程序，通过jni调用java实现。精简代码例如以下：C++程序代码:</p><p></p><pre code_snippet_id="517675" snippet_file_name="blog_20141113_2_8082170" name="code" class="plain">#define LOG_TAG "testmain"

#define LOG_NDEBUG 0

#include <dlfcn.h>

#include <cutils/log.h>

#include <utils/Log.h>

#include <jni.h>

using namespace android;

void wirtePsCaliValToKernel();

int main (int argc, char * argv[]){

    ALOGI("start c");

    wirtePsCaliValToKernel();

    ALOGI("start c end");

    return 0;

}

void wirtePsCaliValToKernel() {

    JavaVM* vm;

    JNIEnv* env;

    // start a VM

    JavaVMInitArgs args;

    JavaVMOption opt;

    opt.optionString =

        "-agentlib:jdwp=transport=dt_android_adb,suspend=n,server=y";

    args.version = JNI_VERSION_1_4;

    args.options = &opt;

    args.nOptions = 1;

    args.ignoreUnrecognized = JNI_FALSE;

    void* libdvm_dso = dlopen("libdvm.so", RTLD_NOW);

    ALOGE_IF(!libdvm_dso, "DdmConnection: %s", dlerror());

    void* libandroid_runtime_dso = dlopen("libandroid_runtime.so", RTLD_NOW);

    ALOGE_IF(!libandroid_runtime_dso, "DdmConnection: %s", dlerror());

    if (!libdvm_dso || !libandroid_runtime_dso) {

        goto error;

    }

    jint (*JNI_CreateJavaVM)(JavaVM** p_vm, JNIEnv** p_env, void* vm_args);

    JNI_CreateJavaVM = (typeof JNI_CreateJavaVM)dlsym(libdvm_dso, "JNI_CreateJavaVM");

    ALOGE_IF(!JNI_CreateJavaVM, "DdmConnection: %s", dlerror());

    jint (*registerNatives)(JNIEnv* env, jclass clazz);

    registerNatives = (typeof registerNatives)dlsym(libandroid_runtime_dso,

        "Java_com_android_internal_util_WithFramework_registerNatives");

    ALOGE_IF(!registerNatives, "DdmConnection: %s", dlerror());

    if (!JNI_CreateJavaVM || !registerNatives) {

        goto error;

    }

    if (JNI_CreateJavaVM(&vm, &env, &args) == 0) {

        jclass startClass;

        jmethodID readPsMeth;

        // register native code

        if (registerNatives(env, 0) == 0) {

            startClass = env->FindClass("android/hardware/Camera");

            if (startClass) {

                ALOGI(" startclass is ok");

                //readPsMeth = env->GetStaticMethodID(startClass, "getCurrentFocusPosition", "(I)V");

                readPsMeth = env->GetMethodID(startClass, "getCurrentFocusPosition", "()I");

                int result = -1;

                if (readPsMeth) {

                    ALOGI("readPsMeth is ok, result = %d ",  result);

                    result = env->CallStaticIntMethod(startClass, readPsMeth);

                    ALOGI("readPsMeth is ok end, result = %d ",  result);

                }else{

                    ALOGE("-->> readPsMeth is fail");

                }

            }else{

                ALOGE("startclass is fail");

            }

        }

    }

    return;

error:

    if (libandroid_runtime_dso) {

        dlclose(libandroid_runtime_dso);

    }

    if (libdvm_dso) {

        dlclose(libdvm_dso);

    }

}

Android.mk:

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE:= testmain

LOCAL_SRC_FILES:=     \

    testmain.cpp

LOCAL_C_INCLUDES :=

LOCAL_MODULE_TAGS := optional eng

LOCAL_SHARED_LIBRARIES += libcutils   \

                          libutils    \

                          liblog    \

                          libandroid_runtime \

                          libnativehelper \

                          libdl \

include $(BUILD_EXECUTABLE)

init.rc改动:

class 值为main时才干开机自己主动启动

service testmain /system/bin/testmain

	class main

	user root

	oneshot

end