为Android中PackageManagerService添加方法

PackageManagerService相关类结构

分析

从上图可以看出若想为PackageManagerService添加方法需要进行以下改动

1，在IPackageManager.aidl文件中增加方法的声明；

2，在PackageManager类中增加抽象方法说明；

3，在ApplicationPackageManager中增加方法，具体实现为调用远程PackageManagerService的方法；

4，在PackageManagerService中增加方法的具体实现；

注：由于MockPackageManager类也继承了PackageManager类，故也需要加入一些实现的代码；增加的方法要设置为hide，或者更改API-List加入新增加的方法

Demo

目标：在PackageManagerService加入方法public String getHello();

第一步：在IPackageManager.aidl增加getHello()方法声明

interface IPackageManager {    PackageInfo getPackageInfo(String packageName, int flags);    int getPackageUid(String packageName);    int[] getPackageGids(String packageName);        String[] currentToCanonicalPackageNames(in String[] names);    String[] canonicalToCurrentPackageNames(in String[] names);    PermissionInfo getPermissionInfo(String name, int flags);        List<PermissionInfo> queryPermissionsByGroup(String group, int flags);        PermissionGroupInfo getPermissionGroupInfo(String name, int flags);        List<PermissionGroupInfo> getAllPermissionGroups(int flags);        ApplicationInfo getApplicationInfo(String packageName, int flags);    ActivityInfo getActivityInfo(in ComponentName className, int flags);    ActivityInfo getReceiverInfo(in ComponentName className, int flags);    .    .      .    .    .    .    String getHello();}

第二步：PackageManager类中增加抽象方法说明

public abstract class PackageManager {    /**     * This exception is thrown when a given package, application, or component     * name can not be found.     */    public static class NameNotFoundException extends AndroidException {        public NameNotFoundException() {        }        public NameNotFoundException(String name) {            super(name);        }    }    .    .    .    .    .    .    /**     * @hide     */    public abstract String getHello();}

第三步：在PackageManagerService中增加getHello()方法的具体实现

public class PackageManagerService extends IPackageManager.Stub {    static final String TAG = "PackageManager";    static final boolean DEBUG_SETTINGS = false;    private static final boolean DEBUG_PREFERRED = false;    static final boolean DEBUG_UPGRADE = false;    private static final boolean DEBUG_INSTALL = false;    private static final boolean DEBUG_REMOVE = false;    private static final boolean DEBUG_SHOW_INFO = false;    private static final boolean DEBUG_PACKAGE_INFO = false;    .    .    .    .    .    .    .    public String getHello(){        return "Hello,PMS";    }}

第四步：在ApplicationPackageManager中增加getHello()方法，具体实现为调用远程PackageManagerService的getHello()方法

final class ApplicationPackageManager extends PackageManager {    private static final String TAG = "ApplicationPackageManager";    private final static boolean DEBUG = false;    private final static boolean DEBUG_ICONS = false;    @Override    public PackageInfo getPackageInfo(String packageName, int flags)            throws NameNotFoundException {        try {            PackageInfo pi = mPM.getPackageInfo(packageName, flags);            if (pi != null) {                return pi;            }        } catch (RemoteException e) {            throw new RuntimeException("Package manager has died", e);        }        throw new NameNotFoundException(packageName);    }    @Override    public String[] currentToCanonicalPackageNames(String[] names) {        try {            return mPM.currentToCanonicalPackageNames(names);        } catch (RemoteException e) {            throw new RuntimeException("Package manager has died", e);        }    }    .    .    .    .    .    .    .        /**     * @hide     */    @Override	public String getHello() {		// TODO Auto-generated method stub		try {			return mPM.isThirdParty(name);		} catch (RemoteException e) {			throw new RuntimeException("Package manager has died", e);		}	}}