Android中實現native服務利用binder與應用通訊

主要講解一下，Android的上層應用通過binder機制調用native服務，下面這個圖，主要用來描述，我們在實現binder相關的bp和bn端的時候，基本的類圖。

基本說明了一下 如何利用binder實現底層的服務，基本實現就是上面這樣一個模板，下面我會就我自己實現的一個demo,詳細說明一下，如何來寫code,之前也是看別人的部落格，參考到的例子，但是例子在我這有很多問題，就改了改，反正是可以正常使用了。

是基本說明了，我的這個demo的類繼承關係，這個demo主要實現了Java上層利用binder調用C++層的bn端，而後C++的bn端再將請求返回給上層的，這樣一個執行個體，這個執行個體主要是做了一個加法運算。

C++實現的native服務

AddService.h

#ifndef ANDROID_GUILH_ADD_SERVICE_H#define ANDROID_GUILH_ADD_SERVICE_H#include <utils/threads.h>#include <utils/RefBase.h>#include <binder/IInterface.h>#include <binder/Parcel.h>#include <binder/IBinder.h>#include <binder/Binder.h>#include <binder/IBinder.h>#include <binder/IServiceManager.h>#include <utils/Log.h>#include <utils/misc.h>#include <binder/Parcel.h>#include <utils/StringArray.h>#include <utils/threads.h>#include <cutils/properties.h>#include "jni.h"#include "JNIHelp.h"#include <stdio.h>#include <signal.h>#include <sys/stat.h>#include <sys/types.h>#include <signal.h>#include <dirent.h>#include <assert.h>namespace android{class AddService : public BBinder{mutable Mutex mLock;int32_t mNextConnId;public:static int instantiate();AddService();virtual ~AddService();virtual status_t onTransact(uint32_t, const Parcel&, Parcel*, uint32_t);};}#endif

AddService.cpp

#include <AddService.h>#include <binder/IServiceManager.h>#include <utils/Debug.h>#include <utils/Log.h>#include <binder/IPCThreadState.h>#include <binder/Parcel.h>//#include <binder/IBinder.h>#include <utils/String8.h>#include <binder/IBinder.h>#include <binder/IServiceManager.h>#include <utils/Log.h>#include <utils/misc.h>#include <binder/Parcel.h>#include <utils/StringArray.h>#include <utils/threads.h>#include <cutils/properties.h>#include "jni.h"#include "JNIHelp.h"//#include "android_util_Binder.h"#include <stdio.h>#include <signal.h>#include <sys/stat.h>#include <sys/types.h>#include <signal.h>#include <dirent.h>#include <assert.h>namespace android {static struct sigaction oldact;static pthread_key_t sigbuskey;sp<IBinder> binder;int AddService::instantiate() {LOGE("AddService instantiate");int r = defaultServiceManager()->addService(String16("flyfot.add"), new AddService());LOGE("AddService r = %d/n", r);return r;}AddService::AddService(){LOGV("AddService created");mNextConnId = 1;pthread_key_create(&sigbuskey, NULL);}AddService::~AddService(){pthread_key_delete(sigbuskey);LOGV("AddService destroyed");}status_t AddService::onTransact(uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) {LOGE("AddDemo", "AddService.cpp:onTransact:" + code);switch (code) {case 0: {LOGI("AddDemo", "addservice::onTransact");//pid_t pid = data.readInt32();//int a = data.readInt32();//int b = data.readInt32();//int num = a + b;//sp < IServiceManager > sm = defaultServiceManager();LOGE("AddService","start get java service");//binder = sm->getService(//String16("zx.java"));//String16 info = data.re//data.enbinder = data.readStrongBinder();LOGE("AddService.cpp","data.readStrongBinbder");if (binder == 0) {LOGE("AddService", "get java local service failed");return NO_ERROR;}int a = data.readInt32();int b = data.readInt32();Parcel _data_sec ;//String16 interface = "cn.zx.callback";_data_sec.writeInterfaceToken(String16("cn.zx.secrity.RemoteSecrityCallback"));_data_sec.writeInt32(a);_data_sec.writeInt32(b);LOGE("AddService", "get java local service sucessful");binder->transact(0,_data_sec, reply);return NO_ERROR;}break;default:return BBinder::onTransact(code, data, reply, flags);}}};

。。。。。待續/。。。。。