Enable Native service in Android to use binder to communicate with Applications

The upper-layer Android applications call the native service through the Binder Mechanism. The figure below mainly describes the basic class diagrams when we implement the BP and Bn related to the binder.

The basic description is how to use binder to implement the underlying service. The basic implementation is the template above. Below I will introduce a demo implemented by myself. I will explain in detail how to write code, I used to read other people's blogs and refer to the examples. However, if there are many problems with this example, I changed it and it can be used normally.

Is basically explained, my demo class inheritance relationship, this demo mainly implements the Java upper layer using binder to call the BN end of the C ++ layer, then the BN end of C ++ returns the request to the upper layer. For such an instance, this instance mainly performs an addition operation.

Native services implemented by C ++

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);}}};

..... To be continued /.....