GS3 4.2.1利用adb安装apk失败问题

GS3更新到4.2.1后，安装自编应用均出现错误INSTALL_FAILED_INTERNAL_ERROR：

解决办法：

1.Setting -> Security -> Verify Apps去掉选择框的选择。

2.Setting -> Security -> Unknown sources去掉选择框的选择。

当安装源代码编译的apk后再次安装Eclipse编译出的apk出现以下错误：

E:\send_file>adb install -r \Development.apk
1255 KB/s (71986 bytes in 0.056s)
        pkg: /data/local/tmp/Development.apk
Failure [INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES]

解决办法：

先卸载apk，再次安装新的apk。

源代码分析：

frameworks/base/services/java/com/android/server/pm/PackageManagerService.java

    public PackageManagerService(Context context, Installer installer,
            boolean factoryTest, boolean onlyCore) {
...
            // 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_DIR, scanMode, 0);
...
            if (!mOnlyCore) {
                EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_DATA_SCAN_START,
                        SystemClock.uptimeMillis());
                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);

以上代码可看出系统会监视五个目录：/system/app /data/app ...

一旦目录中文件出现变动，onEvent将会被调用：

    private final class AppDirObserver extends FileObserver {
...
        public void onEvent(int event, String path) {...
            synchronized (mInstallLock) {
                if ((event&ADD_EVENTS) != 0) {
                    if (p == null) {
                        p = scanPackageLI(fullPath,
                                (mIsRom ? PackageParser.PARSE_IS_SYSTEM
                                        | PackageParser.PARSE_IS_SYSTEM_DIR: 0) |
                                PackageParser.PARSE_CHATTY |
                                PackageParser.PARSE_MUST_BE_APK,
                                SCAN_MONITOR | SCAN_NO_PATHS | SCAN_UPDATE_TIME,
                                System.currentTimeMillis(), UserHandle.ALL);
                        if (p != null) {
                            /*
                             * TODO this seems dangerous as the package may have
                             * changed since we last acquired the mPackages
                             * lock.
                             */
                            // writer
                            synchronized (mPackages) {
                                updatePermissionsLPw(p.packageName, p,
                                        p.permissions.size() > 0 ? UPDATE_PERMISSIONS_ALL : 0);
                            }
                            addedPackage = p.applicationInfo.packageName;
                            addedAppId = UserHandle.getAppId(p.applicationInfo.uid);
                        }
                    }
                }

                // reader
                synchronized (mPackages) {
                    mSettings.writeLPr();
                }
            }
...
            if (addedPackage != null) {
                Bundle extras = new Bundle(1);
                extras.putInt(Intent.EXTRA_UID, addedAppId);
                sendPackageBroadcast(Intent.ACTION_PACKAGE_ADDED, addedPackage,
                        extras, null, null, addedUsers);
            }