PackageInfoUtils类

public static ApplicationInfo generateApplicationInfo(AndroidPackage pkg,
            @PackageManager.ApplicationInfoFlagsBits long flags,
            @NonNull PackageUserStateInternal state, @UserIdInt int userId,
            @Nullable PackageStateInternal pkgSetting) {
        省略代码······

        ApplicationInfo info = PackageInfoWithoutStateUtils.generateApplicationInfoUnchecked(pkg,
                flags, state, userId, false /* assignUserFields */);

        initForUser(info, pkg, userId);

        if (pkgSetting != null) {
            // TODO(b/135203078): Remove PackageParser1/toAppInfoWithoutState and clean all this up
            PackageStateUnserialized pkgState = pkgSetting.getTransientState();
            info.hiddenUntilInstalled = pkgState.isHiddenUntilInstalled();

            //pkgState.getUsesLibraryFiles()和pkgState.getUsesLibraryInfos()获取的是共享库的信息，而这些信息在扫描完毕apk后就有值了
            List<String> usesLibraryFiles = pkgState.getUsesLibraryFiles();
            List usesLibraryInfos = pkgState.getUsesLibraryInfos();
            //存储共享库信息则
            info.sharedLibraryFiles = usesLibraryFiles.isEmpty()
                    ? null : usesLibraryFiles.toArray(new String[0]);

            info.sharedLibraryInfos = usesLibraryInfos.isEmpty() ? null : usesLibraryInfos;
            省略代码······
        }

        省略代码······
        return info;
    }

//PathClassLoader 类

public class PathClassLoader extends BaseDexClassLoader {
}

public class BaseDexClassLoader extends ClassLoader {
  //共享库相关的ClassLoader
  protected final ClassLoader[] sharedLibraryLoaders;
  protected final ClassLoader[] sharedLibraryLoadersAfter;

  protected Class> findClass(String name) throws ClassNotFoundException {
        //查找某个类时，先从共享库对应的ClassLoader中查找，找到则返回，否则从当前apk中查找
        if (sharedLibraryLoaders != null) {
            for (ClassLoader loader : sharedLibraryLoaders) {
                try {
                    return loader.loadClass(name);
                } catch (ClassNotFoundException ignored) {
                }
            }
        }
        // Check whether the class in question is present in the dexPath that
        // this classloader operates on.
        List suppressedExceptions = new ArrayList();
        Class c = pathList.findClass(name, suppressedExceptions);
        if (c != null) {
            return c;
        }
        // Now, check whether the class is present in the "after" shared libraries.
        if (sharedLibraryLoadersAfter != null) {
            for (ClassLoader loader : sharedLibraryLoadersAfter) {
                try {
                    return loader.loadClass(name);
                } catch (ClassNotFoundException ignored) {
                }
            }
        }
        if (c == null) {
            ClassNotFoundException cnfe = new ClassNotFoundException(
                    "Didn't find class \"" + name + "\" on path: " + pathList);
            for (Throwable t : suppressedExceptions) {
                cnfe.addSuppressed(t);
            }
            throw cnfe;
        }
        return c;
    }
}