Android应用程序安装过程解析(源码解析)
Android应用程序安装过程解析
1.程序安装的4大步骤
(1) 拷贝apk文件到指定目录
在Android系统中,apk安装文件是会被保存起来的,默认情况下,用户安装的apk首先会被拷贝到 /data/app 目录下。
/data/app目录是用户有权限访问的目录,在安装apk的时候会自动选择该目录存放用户安装的文件,而系统出厂的apk文件则被放到了 /system 分区下,包括 /system/app,/system/vendor/app,以及 /system/priv-app 等等,该分区只有Root权限的用户才能访问,这也就是为什么在没有Root手机之前,我们无法删除系统出厂的app的原因了。
(2) 解压apk,拷贝文件,创建应用的数据目录
为了加快app的启动速度,apk在安装的时候,会首先将app的可执行文件(dex)拷贝到 /data/dalvik-cache 目录,缓存起来。
然后,在/data/data/目录下创建应用程序的数据目录(以应用的包名命名),存放应用的相关数据,如数据库、xml文件、cache、二进制的so动态库等等。
(3) 解析apk的AndroidManifinest.xml文件
Android系统中,也有一个类似注册表的东西,用来记录当前所有安装的应用的基本信息,每次系统安装或者卸载了任何apk文件,都会更新这个文件。这个文件位于如下目录:
/data/system/packages.xml
系统在安装apk的过程中,会解析apk的AndroidManifinest.xml文件,提取出这个apk的重要信息写入到packages.xml文件中,这些信息包括:权限、应用包名、APK的安装位置、版本、userID等等。
由此,我们就知道了为啥一些应用市场和软件管理类的app能够很清楚地知道当前手机所安装的所有的app,以及这些app的详细信息了。
另外一件事就是Linux的用户Id和用户组Id,以便他可以获得合适的运行权限。
以上这些都是由PackageServiceManager完成的,下面我们会重点介绍PackageServiceManager。
(4) 显示快捷方式
这些应用程序只是相当于在PackageManagerService服务注册好了,如果我们想要在Android桌面上看到这些应用程序,还需要有一个Home应用程序,负责从PackageManagerService服务中把这些安装好的应用程序取出来,并以友好的方式在桌面上展现出来,例如以快捷图标的形式。在Android系统中,负责把系统中已经安装的应用程序在桌面中展现出来的Home应用程序就是Launcher了
2.PackageManagerService的启动过程
Android系统在启动的过程中,会启动一个应用程序管理服务PackageManagerService,这个服务负责扫描系统中特定的目录,找到里面的应用程序文件,即以Apk为后缀的文件,然后对这些文件进解析,得到应用程序的相关信息。
应用程序管理服务PackageManagerService安装应用程序的过程,其实就是解析析应用程序配置文件AndroidManifest.xml的过程,并从里面得到得到应用程序的相关信息,例如得到应用程序的组件Activity、Service、Broadcast Receiver和Content Provider等信息,有了这些信息后,通过ActivityManagerService这个服务,我们就可以在系统中正常地使用这些应用程序了。
应用程序管理服务PackageManagerService是系统启动的时候由SystemServer组件启动的,启后它就会执行应用程序安装的过程,因此,本文将从SystemServer启动PackageManagerService服务的过程开始分析系统中的应用程序安装的过程。
下面我们具体分析每一个步骤。
##Step 1. SystemServer.main这个函数定义在frameworks/base/services/Java/com/android/server/SystemServer.java文件中:
[java] view plain copy
public class SystemServer
{ ...... native public static void init1(String[] args); ...... public static void main(String[] args) { ...... init1(args); ...... } ......
}
SystemServer组件是由Zygote进程负责启动的,启动的时候就会调用它的main函数,这个函数主要调用了JNI方法init1来做一些系统初始化的工作。##Step 2. SystemServer.init1这个函数是一个JNI方法,实现在 frameworks/base/services/jni/com_android_server_SystemServer.cpp文件中:
[cpp] view plain copy
namespace android { extern "C" int system_init(); static void android_server_SystemServer_init1(JNIEnv* env, jobject clazz)
{ system_init();
} /* * JNI registration. */
static JNINativeMethod gMethods[] = { /* name, signature, funcPtr */ { "init1", "([Ljava/lang/String;)V", (void*) android_server_SystemServer_init1 },
}; int register_android_server_SystemServer(JNIEnv* env)
{ return jniRegisterNativeMethods(env, "com/android/server/SystemServer", gMethods, NELEM(gMethods));
} }; // namespace android
这个函数很简单,只是调用了system_init函数来进一步执行操作。##Step 3. libsystem_server.system_init函数system_init实现在libsystem_server库中,源代码位于frameworks/base/cmds/system_server/library/system_init.cpp文件中:
[cpp] view plain copy
extern "C" status_t system_init()
{ LOGI("Entered system_init()"); sp<ProcessState> proc(ProcessState::self()); sp<IServiceManager> sm = defaultServiceManager(); LOGI("ServiceManager: %p\n", sm.get()); sp<GrimReaper> grim = new GrimReaper(); sm->asBinder()->linkToDeath(grim, grim.get(), 0); char propBuf[PROPERTY_VALUE_MAX]; property_get("system_init.startsurfaceflinger", propBuf, "1"); if (strcmp(propBuf, "1") == 0) { // Start the SurfaceFlinger SurfaceFlinger::instantiate(); } // Start the sensor service SensorService::instantiate(); // On the simulator, audioflinger et al don't get started the // same way as on the device, and we need to start them here if (!proc->supportsProcesses()) { // Start the AudioFlinger AudioFlinger::instantiate(); // Start the media playback service MediaPlayerService::instantiate(); // Start the camera service CameraService::instantiate(); // Start the audio policy service AudioPolicyService::instantiate(); } // And now start the Android runtime. We have to do this bit // of nastiness because the Android runtime initialization requires // some of the core system services to already be started. // All other servers should just start the Android runtime at // the beginning of their processes's main(), before calling // the init function. LOGI("System server: starting Android runtime.\n"); AndroidRuntime* runtime = AndroidRuntime::getRuntime(); LOGI("System server: starting Android services.\n"); runtime->callStatic("com/android/server/SystemServer", "init2"); // If running in our own process, just go into the thread // pool. Otherwise, call the initialization finished // func to let this process continue its initilization. if (proc->supportsProcesses()) { LOGI("System server: entering thread pool.\n"); ProcessState::self()->startThreadPool(); IPCThreadState::self()->joinThreadPool(); LOGI("System server: exiting thread pool.\n"); } return NO_ERROR;
}
这个函数首先会初始化SurfaceFlinger、SensorService、AudioFlinger、MediaPlayerService、CameraService和AudioPolicyService这几个服务,然后就通过系统全局唯一的AndroidRuntime实例变量runtime的callStatic来调用SystemServer的init2函数了。关于这个AndroidRuntime实例变量runtime的相关资料,可能参考前面一篇文章Android应用程序进程启动过程的源代码分析一文。## Step 4. AndroidRuntime.callStatic这个函数定义在frameworks/base/core/jni/AndroidRuntime.cpp文件中:
[cpp] view plain copy
/*
* Call a static Java Programming Language function that takes no arguments and returns void.
*/
status_t AndroidRuntime::callStatic(const char* className, const char* methodName)
{ JNIEnv* env; jclass clazz; jmethodID methodId; env = getJNIEnv(); if (env == NULL) return UNKNOWN_ERROR; clazz = findClass(env, className); if (clazz == NULL) { LOGE("ERROR: could not find class '%s'\n", className); return UNKNOWN_ERROR; } methodId = env->GetStaticMethodID(clazz, methodName, "()V"); if (methodId == NULL) { LOGE("ERROR: could not find method %s.%s\n", className, methodName); return UNKNOWN_ERROR; } env->CallStaticVoidMethod(clazz, methodId); return NO_ERROR;
}
这个函数调用由参数className指定的java类的静态成员函数,这个静态成员函数是由参数methodName指定的。上面传进来的参数className的值为"com/android/server/SystemServer",而参数methodName的值为"init2",因此,接下来就会调用SystemServer类的init2函数了。##Step 5. SystemServer.init2这个函数定义在frameworks/base/services/java/com/android/server/SystemServer.java文件中:
[java] view plain copy
public class SystemServer
{ ...... public static final void init2() { Slog.i(TAG, "Entered the Android system server!"); Thread thr = new ServerThread(); thr.setName("android.server.ServerThread"); thr.start(); }
}
这个函数创建了一个ServerThread线程,PackageManagerService服务就是这个线程中启动的了。这里调用了ServerThread实例thr的start函数之后,下面就会执行这个实例的run函数了。##Step 6. ServerThread.run这个函数定义在frameworks/base/services/java/com/android/server/SystemServer.java文件中:
[java] view plain copy
class ServerThread extends Thread { ...... @Override public void run() { ...... IPackageManager pm = null; ...... // Critical services... try { ...... Slog.i(TAG, "Package Manager"); pm = PackageManagerService.main(context, factoryTest != SystemServer.FACTORY_TEST_OFF); ...... } catch (RuntimeException e) { Slog.e("System", "Failure starting core service", e); } ...... } ......
}
这个函数除了启动PackageManagerService服务之外,还启动了其它很多的服务,例如在前面学习Activity和Service的几篇文章中经常看到的ActivityManagerService服务,有兴趣的读者可以自己研究一下。##Step 7. PackageManagerService.main这个函数定义在frameworks/base/services/java/com/android/server/PackageManagerService.java文件中:
[cpp] view plain copy
class PackageManagerService extends IPackageManager.Stub { ...... public static final IPackageManager main(Context context, boolean factoryTest) { PackageManagerService m = new PackageManagerService(context, factoryTest); ServiceManager.addService("package", m); return m; } ......
}
3.常见的4种安装场景
1.系统应用安装――开机时完成,没有安装界面
2.网络下载应用安装――通过market应用完成,没有安装界面
3.ADB工具安装――没有安装界面。
4.第三方应用安装――通过SD卡里的APK文件安装,有安装界面,由 packageinstaller.apk应用处理安装及卸载过程的界面。
安装过程:
复制APK安装包到data/app目录下,解压并扫描安装包,把dex文件(Dalvik字节码)保存到dalvik-cache目录,并data/data目录下创建对应的应用数据目录。
卸载过程:
删除安装过程中在上述三个目录下创建的文件及目录。
(1)系统应用安装――开机时完成,没有安装界面
PackageManagerService处理各种应用的安装,卸载,管理等工作,开机时由systemServer启动此服务
在创建这个PackageManagerService服务实例时,会在PackageManagerService类的构造函数中开始执行安装应用程序的过程:
PackageManagerService核心代码
[java] view plain copy
class PackageManagerService extends IPackageManager.Stub { ...... public PackageManagerService(Context context, boolean factoryTest) { ...... mSetting = new Setting();synchronized (mInstallLock) { synchronized (mPackages) { ...... File dataDir = Environment.getDataDirectory(); mAppDataDir = new File(dataDir, "data"); mSecureAppDataDir = new File(dataDir, "secure/data"); mRestoredSetting = mASetting.readLP();mDrmAppPrivateInstallDir = new File(dataDir, "app-private"); ...... mFrameworkDir = new File(Environment.getRootDirectory(), "framework"); mDalvikCacheDir = new File(dataDir, "dalvik-cache"); ...... // Find base frameworks (resource packages without code). mFrameworkInstallObserver = new AppDirObserver( mFrameworkDir.getPath(), OBSERVER_EVENTS, true); mFrameworkInstallObserver.startWatching(); scanDirLI(mFrameworkDir, PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR, scanMode | SCAN_NO_DEX, 0); // Collect all system packages. mSystemAppDir = new File(Environment.getRootDirectory(), "app"); mSystemInstallObserver = new AppDirObserver( mSystemAppDir.getPath(), OBSERVER_EVENTS, true); mSystemInstallObserver.startWatching(); scanDirLI(mSystemAppDir, PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR, scanMode, 0); // Collect all vendor packages. mVendorAppDir = new File("/vendor/app"); mVendorInstallObserver = new AppDirObserver( mVendorAppDir.getPath(), OBSERVER_EVENTS, true); mVendorInstallObserver.startWatching(); scanDirLI(mVendorAppDir, PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR, scanMode, 0); mAppInstallObserver = new AppDirObserver( mAppInstallDir.getPath(), OBSERVER_EVENTS, false); mAppInstallObserver.startWatching(); scanDirLI(mAppInstallDir, 0, scanMode, 0); mDrmAppInstallObserver = new AppDirObserver( mDrmAppPrivateInstallDir.getPath(), OBSERVER_EVENTS, false); mDrmAppInstallObserver.startWatching(); scanDirLI(mDrmAppPrivateInstallDir, PackageParser.PARSE_FORWARD_LOCK, scanMode, 0); ...... final boolean regrantPermissions = mSetting.mInternalSDKplatform != mSdkVersion;updatePermissionsLP(null,null,true,rregrantPermissions .regrantPermissions );msetting.writeLP();} } } ......
}
#这里会调用scanDirLI函数来扫描移动设备上的下面这五个目录中的Apk文件/system/framework/system/app/vendor/app/data/app/data/app-private由于Android每次启动的时候都需要安装一次信息,但是有些信息是保持不变的,例如Linux用户组Id,PackageManagerService 每次安装程序之后,都会把这些程序的信息保存下来,以便下次使用,
恢复上一次程序的安装信息是通过PackageManagerService 的成员变量mSetting的readLP()来实现的,恢复信息之后就开始扫描和安装app了。
#扫描安装app##Step 8. PackageManagerService.scanDirLI这个函数定义在frameworks/base/services/java/com/android/server/PackageManagerService.java文件中:
[java] view plain copy
class PackageManagerService extends IPackageManager.Stub { ...... private void scanDirLI(File dir, int flags, int scanMode, long currentTime) { String[] files = dir.list(); ...... int i; for (i=0; i<files.length; i++) { File file = new File(dir, files[i]); if (!isPackageFilename(files[i])) { // Ignore entries which are not apk's continue; } PackageParser.Package pkg = scanPackageLI(file, flags|PackageParser.PARSE_MUST_BE_APK, scanMode, currentTime); // Don't mess around with apps in system partition. if (pkg == null && (flags & PackageParser.PARSE_IS_SYSTEM) == 0 && mLastScanError == PackageManager.INSTALL_FAILED_INVALID_APK) { // Delete the apk Slog.w(TAG, "Cleaning up failed install of " + file); file.delete(); } } } ......
}
对于目录中的每一个文件,如果是以后Apk作为后缀名,那么就调用scanPackageLI函数来对它进行解析和安装。##Step 9. PackageManagerService.scanPackageLI这个函数定义在frameworks/base/services/java/com/android/server/PackageManagerService.java文件中:
[java] view plain copy 在CODE上查看代码片派生到我的代码片
class PackageManagerService extends IPackageManager.Stub { ...... private PackageParser.Package scanPackageLI(File scanFile, int parseFlags, int scanMode, long currentTime) { ...... String scanPath = scanFile.getPath(); parseFlags |= mDefParseFlags; PackageParser pp = new PackageParser(scanPath); ...... final PackageParser.Package pkg = pp.parsePackage(scanFile, scanPath, mMetrics, parseFlags); ...... return scanPackageLI(pkg, parseFlags, scanMode | SCAN_UPDATE_SIGNATURE, currentTime); } ......
}
这个函数首先会为这个Apk文件创建一个PackageParser实例,接着调用这个实例的parsePackage函数来对这个Apk文件进行解析。这个函数最后还会调用另外一个版本的scanPackageLI函数把来解析后得到的应用程序信息保存在PackageManagerService中。## Step 10. PackageParser.parsePackage这个函数定义在frameworks/base/core/java/android/content/pm/PackageParser.java文件中:
[java] view plain copy 在CODE上查看代码片派生到我的代码片
public class PackageParser { ...... public Package parsePackage(File sourceFile, String destCodePath, DisplayMetrics metrics, int flags) { ...... mArchiveSourcePath = sourceFile.getPath(); ...... XmlResourceParser parser = null; AssetManager assmgr = null; boolean assetError = true; try { assmgr = new AssetManager(); int cookie = assmgr.addAssetPath(mArchiveSourcePath); if(cookie != 0) { parser = assmgr.openXmlResourceParser(cookie, "AndroidManifest.xml"); assetError = false; } else { ...... } } catch (Exception e) { ...... } ...... String[] errorText = new String[1]; Package pkg = null; Exception errorException = null; try { // XXXX todo: need to figure out correct configuration. Resources res = new Resources(assmgr, metrics, null); pkg = parsePackage(res, parser, flags, errorText); } catch (Exception e) { ...... } ...... parser.close(); assmgr.close(); // Set code and resource paths pkg.mPath = destCodePath; pkg.mScanPath = mArchiveSourcePath; //pkg.applicationInfo.sourceDir = destCodePath; //pkg.applicationInfo.publicSourceDir = destRes; pkg.mSignatures = null; return pkg; } ......
}
每一个Apk文件都是一个归档文件,它里面包含了Android应用程序的配置文件AndroidManifest.xml,这里主要就是要对这个配置文件就行解析了,从Apk归档文件中得到这个配置文件后,就调用另一外版本的parsePackage函数对这个应用程序进行解析了:
[java] view plain copy 在CODE上查看代码片派生到我的代码片
public class PackageParser { ...... private Package parsePackage( Resources res, XmlResourceParser parser, int flags, String[] outError) throws XmlPullParserException, IOException { ...... String pkgName = parsePackageName(parser, attrs, flags, outError); ...... final Package pkg = new Package(pkgName); ...... int type; ...... TypedArray sa = res.obtainAttributes(attrs, com.android.internal.R.styleable.AndroidManifest); ...... while ((type=parser.next()) != parser.END_DOCUMENT && (type != parser.END_TAG || parser.getDepth() > outerDepth)) { if (type == parser.END_TAG || type == parser.TEXT) { continue; } String tagName = parser.getName(); if (tagName.equals("application")) { ...... if (!parseApplication(pkg, res, parser, attrs, flags, outError)) { return null; } } else if (tagName.equals("permission-group")) { ...... } else if (tagName.equals("permission")) { ...... } else if (tagName.equals("permission-tree")) { ...... } else if (tagName.equals("uses-permission")) { ...... } else if (tagName.equals("uses-configuration")) { ...... } else if (tagName.equals("uses-feature")) { ...... } else if (tagName.equals("uses-sdk")) { ...... } else if (tagName.equals("supports-screens")) { ...... } else if (tagName.equals("protected-broadcast")) { ...... } else if (tagName.equals("instrumentation")) { ...... } else if (tagName.equals("original-package")) { ...... } else if (tagName.equals("adopt-permissions")) { ...... } else if (tagName.equals("uses-gl-texture")) { ...... } else if (tagName.equals("compatible-screens")) { ...... } else if (tagName.equals("eat-comment")) { ...... } else if (RIGID_PARSER) { ...... } else { ...... } } ...... return pkg; } ......
}
这里就是对AndroidManifest.xml文件中的各个标签进行解析了,各个标签的含义可以参考官方文档http://developer.android.com/guide/topics/manifest/manifest-intro.html,这里我们只简单看一下application标签的解析,这是通过调用parseApplication函数来进行的。## Step 11. PackageParser.parseApplication这个函数定义在frameworks/base/core/java/android/content/pm/PackageParser.java文件中:
[java] view plain copy 在CODE上查看代码片派生到我的代码片
public class PackageParser { ...... private boolean parseApplication(Package owner, Resources res, XmlPullParser parser, AttributeSet attrs, int flags, String[] outError) throws XmlPullParserException, IOException { final ApplicationInfo ai = owner.applicationInfo; final String pkgName = owner.applicationInfo.packageName; TypedArray sa = res.obtainAttributes(attrs, com.android.internal.R.styleable.AndroidManifestApplication); ...... int type; while ((type=parser.next()) != parser.END_DOCUMENT && (type != parser.END_TAG || parser.getDepth() > innerDepth)) { if (type == parser.END_TAG || type == parser.TEXT) { continue; } String tagName = parser.getName(); if (tagName.equals("activity")) { Activity a = parseActivity(owner, res, parser, attrs, flags, outError, false); ...... owner.activities.add(a); } else if (tagName.equals("receiver")) { Activity a = parseActivity(owner, res, parser, attrs, flags, outError, true); ...... owner.receivers.add(a); } else if (tagName.equals("service")) { Service s = parseService(owner, res, parser, attrs, flags, outError); ...... owner.services.add(s); } else if (tagName.equals("provider")) { Provider p = parseProvider(owner, res, parser, attrs, flags, outError); ...... owner.providers.add(p); } else if (tagName.equals("activity-alias")) { Activity a = parseActivityAlias(owner, res, parser, attrs, flags, outError); ...... owner.activities.add(a); } else if (parser.getName().equals("meta-data")) { ...... } else if (tagName.equals("uses-library")) { ...... } else if (tagName.equals("uses-package")) { ...... } else { ...... } } return true; } ......
}
这里就是对AndroidManifest.xml文件中的application标签进行解析了,我们常用到的标签就有activity、service、receiver和provider,各个标签的含义可以参考官方文档http://developer.android.com/guide/topics/manifest/manifest-intro.html。这里解析完成后,一层层返回到Step 9中,调用另一个版本的scanPackageLI函数把来解析后得到的应用程序信息保存下来。##Step 12. PackageManagerService.scanPackageLI这个函数定义在frameworks/base/services/java/com/android/server/PackageManagerService.java文件中:
[java] view plain copy 在CODE上查看代码片派生到我的代码片
class PackageManagerService extends IPackageManager.Stub { ...... // Keys are String (package name), values are Package. This also serves // as the lock for the global state. Methods that must be called with // this lock held have the prefix "LP". final HashMap<String, PackageParser.Package> mPackages = new HashMap<String, PackageParser.Package>(); ...... // All available activities, for your resolving pleasure. final ActivityIntentResolver mActivities = new ActivityIntentResolver(); // All available receivers, for your resolving pleasure. final ActivityIntentResolver mReceivers = new ActivityIntentResolver(); // All available services, for your resolving pleasure. final ServiceIntentResolver mServices = new ServiceIntentResolver(); // Keys are String (provider class name), values are Provider. final HashMap<ComponentName, PackageParser.Provider> mProvidersByComponent = new HashMap<ComponentName, PackageParser.Provider>(); ...... private PackageParser.Package scanPackageLI(PackageParser.Package pkg, int parseFlags, int scanMode, long currentTime) { ...... synchronized (mPackages) { ...... // Add the new setting to mPackages mPackages.put(pkg.applicationInfo.packageName, pkg); ...... int N = pkg.providers.size(); int i; for (i=0; i<N; i++) { PackageParser.Provider p = pkg.providers.get(i); p.info.processName = fixProcessName(pkg.applicationInfo.processName, p.info.processName, pkg.applicationInfo.uid); mProvidersByComponent.put(new ComponentName(p.info.packageName, p.info.name), p); ...... } N = pkg.services.size(); for (i=0; i<N; i++) { PackageParser.Service s = pkg.services.get(i); s.info.processName = fixProcessName(pkg.applicationInfo.processName, s.info.processName, pkg.applicationInfo.uid); mServices.addService(s); ...... } N = pkg.receivers.size(); r = null; for (i=0; i<N; i++) { PackageParser.Activity a = pkg.receivers.get(i); a.info.processName = fixProcessName(pkg.applicationInfo.processName, a.info.processName, pkg.applicationInfo.uid); mReceivers.addActivity(a, "receiver"); ...... } N = pkg.activities.size(); for (i=0; i<N; i++) { PackageParser.Activity a = pkg.activities.get(i); a.info.processName = fixProcessName(pkg.applicationInfo.processName, a.info.processName, pkg.applicationInfo.uid); mActivities.addActivity(a, "activity"); ...... } ...... } ...... return pkg; } ......
}
这个函数主要就是把前面解析应用程序得到的package、provider、service、receiver和activity等信息保存在PackageManagerService服务中了。
PackageManagerService的作用总结:
1)从apk, xml中载入pacakge信息, 存储到内部成员变量中, 用于后面的查找. 关键的方法是scanPackageLI().
2)各种查询操作, 包括query Intent操作.
3)install package和delete package的操作. 还有后面的关键方法是installPackageLI().
后面重点介绍installPackageLI,后面的额方式本质都会调用它。
(2)从网络上下载应用:
下载完成后,会自动调用Packagemanager的安装方法installPackage()
“`
/* Called when a downloaded package installation has been confirmed by the user */
由英文注释可见PackageManagerService类的installPackage()函数为安装程序入口。
[java] view plain copy
public void installPackage(
final Uri packageURI, final IPackageInstallObserver observer, final int flags,
final String installerPackageName) {
mContext.enforceCallingOrSelfPermission(
android.Manifest.permission.INSTALL_PACKAGES, null);
Message msg = mHandler.obtainMessage(INIT_COPY);
msg.obj = new InstallParams(packageURI, observer, flags,
installerPackageName);
mHandler.sendMessage(msg);
}
其中是通过PackageHandler的实例mhandler.sendMessage(msg)把信息发给继承Handler的类HandleMessage()方法
[java] view plain copy
class PackageHandler extends Handler{
*******省略若干**********
public void handleMessage(Message msg) {
try {
doHandleMessage(msg);
} finally {
Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
}
}
********省略若干************
}
把信息发给doHandleMessage()方法,方法中用switch()语句进行判定传来Message
[java] view plain copy
void doHandleMessage(Message msg) {
switch (msg.what) {
case INIT_COPY: { if (DEBUG_SD_INSTALL) Log.i(TAG, "init_copy"); HandlerParams params = (HandlerParams) msg.obj; int idx = mPendingInstalls.size(); if (DEBUG_SD_INSTALL) Log.i(TAG, "idx=" + idx); // If a bind was already initiated we dont really // need to do anything. The pending install // will be processed later on. if (!mBound) { // If this is the only one pending we might // have to bind to the service again. if (!connectToService()) { Slog.e(TAG, "Failed to bind to media container service"); params.serviceError(); return; } else { // Once we bind to the service, the first // pending request will be processed. mPendingInstalls.add(idx, params); } } else { mPendingInstalls.add(idx, params); // Already bound to the service. Just make // sure we trigger off processing the first request. if (idx == 0) { mHandler.sendEmptyMessage(MCS_BOUND); } } break; } case MCS_BOUND: { if (DEBUG_SD_INSTALL) Log.i(TAG, "mcs_bound"); if (msg.obj != null) { mContainerService = (IMediaContainerService) msg.obj; } if (mContainerService == null) { // Something seriously wrong. Bail out Slog.e(TAG, "Cannot bind to media container service"); for (HandlerParams params : mPendingInstalls) { mPendingInstalls.remove(0); // Indicate service bind error params.serviceError(); } mPendingInstalls.clear(); } else if (mPendingInstalls.size() > 0) { HandlerParams params = mPendingInstalls.get(0); if (params != null) { params.startCopy(); } } else { // Should never happen ideally. Slog.w(TAG, "Empty queue"); } break; } ****************省略若干**********************
}
}
public final boolean sendMessage (Message msg)public final boolean sendEmptyMessage (int what)两者参数有别。然后调用抽象类HandlerParams中的一个startCopy()方法abstract class HandlerParams {final void startCopy() {***************若干if语句判定否这打回handler消息*******handleReturnCode();}
}handleReturnCode()复写了两次其中有一次是删除时要调用的,只列出安装调用的一个方法
[java] view plain copy
@Override
void handleReturnCode() {
// If mArgs is null, then MCS couldn’t be reached. When it
// reconnects, it will try again to install. At that point, this
// will succeed.
if (mArgs != null) {
processPendingInstall(mArgs, mRet);
}
}
这时可以清楚的看见 processPendingInstall()被调用。其中run()方法如下[java] view plain copy
run(){
synchronized (mInstallLock) { ************省略***************** installPackageLI(args, true, res); }
}
instaPacakgeLI()args,res参数分析 -----------------------------------------------------------------------------------------//InstallArgs 是在PackageService定义的static abstract class InstallArgs 静态抽象类。
[java] view plain copy
static abstract class InstallArgs {
其中定义了flag标志,packageURL,创建文件,拷贝apk,修改包名称,
还有一些删除文件的清理,释放存储函数。
***********************************************************
}
class PackageInstalledInfo {
String name;
int uid;
PackageParser.Package pkg;
int returnCode;
PackageRemovedInfo removedInfo;
}
[java] view plain copy
private void installPackageLI(InstallArgs args,
boolean newInstall, PackageInstalledInfo res) {
int pFlags = args.flags;
String installerPackageName = args.installerPackageName;
File tmpPackageFile = new File(args.getCodePath());
boolean forwardLocked = ((pFlags & PackageManager.INSTALL_FORWARD_LOCK) != 0);
boolean onSd = ((pFlags & PackageManager.INSTALL_EXTERNAL) != 0);
boolean replace = false;
int scanMode = (onSd ? 0 : SCAN_MONITOR) | SCAN_FORCE_DEX | SCAN_UPDATE_SIGNATURE
| (newInstall ? SCAN_NEW_INSTALL : 0);
// Result object to be returned
res.returnCode = PackageManager.INSTALL_SUCCEEDED;
// Retrieve PackageSettings and parse package
int parseFlags = PackageParser.PARSE_CHATTY |
(forwardLocked ? PackageParser.PARSE_FORWARD_LOCK : 0) |
(onSd ? PackageParser.PARSE_ON_SDCARD : 0);
parseFlags |= mDefParseFlags;
PackageParser pp = new PackageParser(tmpPackageFile.getPath());
pp.setSeparateProcesses(mSeparateProcesses);
final PackageParser.Package pkg = pp.parsePackage(tmpPackageFile,
null, mMetrics, parseFlags);
if (pkg == null) {
res.returnCode = pp.getParseError();
return;
}
String pkgName = res.name = pkg.packageName;
if ((pkg.applicationInfo.flags&ApplicationInfo.FLAG_TEST_ONLY) != 0) {
if ((pFlags&PackageManager.INSTALL_ALLOW_TEST) == 0) {
res.returnCode = PackageManager.INSTALL_FAILED_TEST_ONLY;
return;
}
}
if (GET_CERTIFICATES && !pp.collectCertificates(pkg, parseFlags)) {
res.returnCode = pp.getParseError();
return;
}
// Get rid of all references to package scan path via parser.
pp = null;
String oldCodePath = null;
boolean systemApp = false;
synchronized (mPackages) {
// Check if installing already existing package
if ((pFlags&PackageManager.INSTALL_REPLACE_EXISTING) != 0) {
String oldName = mSettings.mRenamedPackages.get(pkgName);
if (pkg.mOriginalPackages != null
&& pkg.mOriginalPackages.contains(oldName)
&& mPackages.containsKey(oldName)) {
// This package is derived from an original package,
// and this device has been updating from that original
// name. We must continue using the original name, so
// rename the new package here.
pkg.setPackageName(oldName);
pkgName = pkg.packageName;
replace = true;
} else if (mPackages.containsKey(pkgName)) {
// This package, under its official name, already exists
// on the device; we should replace it.
replace = true;
}
}
PackageSetting ps = mSettings.mPackages.get(pkgName);
if (ps != null) {
oldCodePath = mSettings.mPackages.get(pkgName).codePathString;
if (ps.pkg != null && ps.pkg.applicationInfo != null) {
systemApp = (ps.pkg.applicationInfo.flags &
ApplicationInfo.FLAG_SYSTEM) != 0;
}
}
}
if (systemApp && onSd) {
// Disable updates to system apps on sdcard
Slog.w(TAG, “Cannot install updates to system apps on sdcard”);
res.returnCode = PackageManager.INSTALL_FAILED_INVALID_INSTALL_LOCATION;
return;
}
if (!args.doRename(res.returnCode, pkgName, oldCodePath)) {
res.returnCode = PackageManager.INSTALL_FAILED_INSUFFICIENT_STORAGE;
return;
}
// Set application objects path explicitly after the rename
setApplicationInfoPaths(pkg, args.getCodePath(), args.getResourcePath());
pkg.applicationInfo.nativeLibraryDir = args.getNativeLibraryPath();
if (replace) {
replacePackageLI(pkg, parseFlags, scanMode,
installerPackageName, res);
} else {
installNewPackageLI(pkg, parseFlags, scanMode,
installerPackageName,res);
}
}
最后判断如果以前不存在那么调用installNewPackageLI()
[java] view plain copy
private void installNewPackageLI(PackageParser.Package pkg,
int parseFlags,int scanMode,
String installerPackageName, PackageInstalledInfo res) {
*************省略若干***************************************
PackageParser.Package newPackage = scanPackageLI(pkg, parseFlags, scanMode,
System.currentTimeMillis());
*************省略若干****************************************
}
最后终于回到了和开机安装一样的地方.与开机方式安装调用统一方法。#(3)从ADB工具安装 其入口函数源文件为pm.java (源文件路径:android\frameworks\base\cmds\pm\src\com\android\commands\pm\pm.java)其中\system\framework\pm.jar 包管理库包管理脚本 \system\bin\pm 解析showUsage就是使用方法
[java] view plain copy
private static void showUsage() {
System.err.println(“usage: pm [list|path|install|uninstall]”);
System.err.println(” pm list packages [-f]”);
System.err.println(” pm list permission-groups”);
System.err.println(” pm list permissions [-g] [-f] [-d] [-u] [GROUP]”);
System.err.println(” pm list instrumentation [-f] [TARGET-PACKAGE]”);
System.err.println(” pm list features”);
System.err.println(” pm path PACKAGE”);
System.err.println(” pm install [-l] [-r] [-t] [-i INSTALLER_PACKAGE_NAME] [-s] [-f] PATH”);
System.err.println(” pm uninstall [-k] PACKAGE”);
System.err.println(” pm enable PACKAGE_OR_COMPONENT”);
System.err.println(” pm disable PACKAGE_OR_COMPONENT”);
System.err.println(” pm setInstallLocation [0/auto] [1/internal] [2/external]”);
************省略****************
}
安装时候会调用 runInstall()方法
[java] view plain copy
private void runInstall() {
int installFlags = 0;
String installerPackageName = null;
String opt;
while ((opt=nextOption()) != null) {
if (opt.equals(“-l”)) {
installFlags |= PackageManager.INSTALL_FORWARD_LOCK;
} else if (opt.equals(“-r”)) {
installFlags |= PackageManager.INSTALL_REPLACE_EXISTING;
} else if (opt.equals(“-i”)) {
installerPackageName = nextOptionData();
if (installerPackageName == null) {
System.err.println(“Error: no value specified for -i”);
showUsage();
return;
}
} else if (opt.equals(“-t”)) {
installFlags |= PackageManager.INSTALL_ALLOW_TEST;
} else if (opt.equals(“-s”)) {
// Override if -s option is specified.
installFlags |= PackageManager.INSTALL_EXTERNAL;
} else if (opt.equals(“-f”)) {
// Override if -s option is specified.
installFlags |= PackageManager.INSTALL_INTERNAL;
} else {
System.err.println(“Error: Unknown option: ” + opt);
showUsage();
return;
}
}
String apkFilePath = nextArg();
System.err.println(“\tpkg: ” + apkFilePath);
if (apkFilePath == null) {
System.err.println(“Error: no package specified”);
showUsage();
return;
}
PackageInstallObserver obs = new PackageInstallObserver();
try {
mPm.installPackage(Uri.fromFile(new File(apkFilePath)), obs, installFlags,
installerPackageName);
synchronized (obs) {
while (!obs.finished) {
try {
obs.wait();
} catch (InterruptedException e) {
}
}
if (obs.result == PackageManager.INSTALL_SUCCEEDED) {
System.out.println(“Success”);
} else {
System.err.println(“Failure [”
+ installFailureToString(obs.result)
+ “]”);
}
}
} catch (RemoteException e) {
System.err.println(e.toString());
System.err.println(PM_NOT_RUNNING_ERR);
}
}
其中的
PackageInstallObserver obs = new PackageInstallObserver();
mPm.installPackage(Uri.fromFile(new File(apkFilePath)), obs, installFlags,installerPackageName);
如果安装成功obs.result == PackageManager.INSTALL_SUCCEEDED)又因为有IPackageManage mPm;mPm = IpackageManager.Stub.asInterface(ServiceManager.getService("package"));Stub是接口IPackageManage的静态抽象类,asInterface是返回IPackageManager代理的静态方法。因为class PackageManagerService extends IPackageManager.Stub所以mPm.installPackage 调用 /* Called when a downloaded package installation has been confirmed by the user */public void installPackage(final Uri packageURI, final IPackageInstallObserver observer, final int flags,final String installerPackageName) 这样就是从网络下载安装的入口了。#(4)从SD卡安装系统调用PackageInstallerActivity.java(/home/zhongda/androidSRC/vortex-8inch-for-hoperun/packages/apps/PackageInstaller/src/com/android/packageinstaller)进入这个Activity会判断信息是否有错,然后调用private void initiateInstall()判断是否曾经有过同名包的安装,或者包已经安装通过后执行private void startInstallConfirm() 点击OK按钮后经过一系列的安装信息的判断Intent跳转到
[java] view plain copy
public class InstallAppProgress extends Activity implements View.OnClickListener, OnCancelListener
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
Intent intent = getIntent();
mAppInfo = intent.getParcelableExtra(PackageUtil.INTENT_ATTR_APPLICATION_INFO);
mPackageURI = intent.getData();
initView();
}
方法中调用了initView()方法
[java] view plain copy
public void initView() {
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.op_progress);
int installFlags = 0;
PackageManager pm = getPackageManager();
try {
PackageInfo pi = pm.getPackageInfo(mAppInfo.packageName,
PackageManager.GET_UNINSTALLED_PACKAGES);
if(pi != null) {
installFlags |= PackageManager.INSTALL_REPLACE_EXISTING;
}
} catch (NameNotFoundException e) {
}
if((installFlags & PackageManager.INSTALL_REPLACE_EXISTING )!= 0) {
Log.w(TAG, “Replacing package:” + mAppInfo.packageName);
}
PackageUtil.AppSnippet as = PackageUtil.getAppSnippet(this, mAppInfo,
mPackageURI);
mLabel = as.label;
PackageUtil.initSnippetForNewApp(this, as, R.id.app_snippet);
mStatusTextView = (TextView)findViewById(R.id.center_text);
mStatusTextView.setText(R.string.installing);
mProgressBar = (ProgressBar) findViewById(R.id.progress_bar);
mProgressBar.setIndeterminate(true);
// Hide button till progress is being displayed
mOkPanel = (View)findViewById(R.id.buttons_panel);
mDoneButton = (Button)findViewById(R.id.done_button);
mLaunchButton = (Button)findViewById(R.id.launch_button);
mOkPanel.setVisibility(View.INVISIBLE);
String installerPackageName = getIntent().getStringExtra(
Intent.EXTRA_INSTALLER_PACKAGE_NAME);
PackageInstallObserver observer = new PackageInstallObserver();
pm.installPackage(mPackageURI, observer, installFlags, installerPackageName);
}
“`
方法最后我们可以看到再次调用安装接口完成安装。
对于mSetting的介绍还不完善,后续会继续补充
本文是读过下面的几篇博客和Android系统源代码情景分析之后写成的,感谢各位作者。
参考:
http://ticktick.blog.51cto.com/823160/1669525
http://blog.csdn.net/hdhd588/article/details/6739281
http://blog.csdn.net/luoshengyang/article/details/6766010
《Android系统源代码情景分析》
Android应用程序安装过程解析(源码解析)相关推荐
- Android 系统 (79)---Android应用程序安装过程解析
Android应用程序安装过程解析 Android应用程序安装过程解析 1.程序安装的4大步骤 (1) 拷贝apk文件到指定目录 在Android系统中,apk安装文件是会被保存起来的,默认情况下,用 ...
- Android开发知识(二十二)LayoutInflater装载xml布局过程的源码解析
文章目录 前言 LayoutInflater实例 LayoutInflater的装载过程 include 标签解析 merge 标签解析 attachToRoot参数解析 View创建过程 (1)判断 ...
- Android OpenGL ES 学习(十) – GLSurfaceView 源码解析GL线程以及自定义 EGL
OpenGL 学习教程 Android OpenGL ES 学习(一) – 基本概念 Android OpenGL ES 学习(二) – 图形渲染管线和GLSL Android OpenGL ES 学 ...
- Android技术栈--HashMap和ArrayMap源码解析
1 总览 WARNING!!:本文字数较多,内容较为完整并且部分内容难度较大,阅读本文需要较长时间,建议读者分段并耐心阅读. 本文会对 Android 中常用的数据结构进行源码解析,包括 HashMa ...
- Qt源码解析-源码解析-QVideoWidget播放手机视频旋转问题
Qt源码解析 索引 Qt源码解析-源码解析-QVideoWidget播放手机视频旋转问题 问题描述与复现 使用手机拍摄的视频是竖屏的,上传后,使用QVideoWidget播放,变成横屏. 总结,可以让 ...
- 【SpringBoot】最新版2019Spring Boot配置解析,源码解析(速成SpringBoot)——学习笔记版【2】
SpringBoot配置文件 文章目录 SpringBoot配置文件 四.配置文件 1.简介 2.YAML用法 2.1 简介 2.2语法 3.为属性注入值 3.1使用.yml配置文件 3.1编写.ym ...
- 安卓开发者必看:Android的数据结构与算法——ArrayList源码解析
作者:JerryloveEmily 原文链接:https://www.jianshu.com/p/159426e2aaf6 文章有点长,比较啰嗦,请耐心看完! 一.概述 首先得明白ArrayList在 ...
- Android应用程序安装过程源代码分析(1)
Android系统在启动的过程中,会启动一个应用程序管理服务PackageManagerService,这个服务负责扫描系统中特定的目录,找到里面的应用程序文件,即以Apk为后缀的文件,然后对这些文件 ...
- Android经典著名的百大框架源码解析(retrofit、Okhttp、Glide、Zxing、dagger等等)
我们Android程序员每天都要和源码打交道.经过数年的学习,大多数程序员可以"写"代码,或者至少是拷贝并修改代码.而且,我们教授编程的方式强调编写代码的艺术,而不是如何阅读代码. ...
最新文章
- 打开浏览器的包 node_如何发布可在浏览器和Node中使用的软件包
- pytorch2——Pytorch基础数据结构——张量(深度之眼)
- Oracle导入csv数据字符集,用SQLLDR把.CSV文件导入到数据库时,出现无法定位字符集句柄以用于字符集标识(0)...
- ppt给图片增加高斯模糊_制作PPT时,图片不清晰你如何处理?
- 文献记录(part57)--半监督学习方法
- WDCP管理面板安装启动EXIF、bcmath完整步骤
- k8s pod MySQL环境变量,如何使用Kubernetes的configmap通过环境变量注入到pod里
- 从 Jacobian 矩阵、Hessian 矩阵到 Theano 实现
- 免费下载IEEE、SCI论文的网站
- Tensorflow学习笔记-基于LeNet5结构的ORL数据集人脸识别
- C语言程序——输入三角形的边长求面积
- Mysql 实现行转列功能
- 三行情书 计算机网络,“学霸式”三行情书走红!句子很短,爱你如诗
- 监听Dom节点失焦触发方法的几个思路
- 数据结构第一课:希尔排序和选择排序的时间复杂度随机数组的生成
- 3 WOW的各种文件的格式(WOWMapView Group)
- 安卓系统控制服务器,安卓系统远程控制云服务器
- mongoDB镜像下载
- 基因相关性(C语言)
- java调用授权接口oauth2_微信授权就是这个原理,Spring Cloud OAuth2 授权码模式
热门文章
- 通过CND方式引入elementui,vue,vuex,vue-router
- STM32单片机-低功耗设置
- IP数据库的比较和选择
- 用java实现matlab的随机函数randsrc(m,n,[alphabet; prob])
- centos 7-aarch64如何替换yum源
- VC的血与泪,最难尽调的是人性————失败风投案例分析
- cpu使用率(cpu使用率很低最大频率很高)
- 青云热链系列之听区块链里最真实的声音6月14日将举行
- git 更新密码之后出现异常(雾)
- 高屋建瓴-------谈观看朱老师视频有感