xposed开发

https://www.52pojie.cn/thread-853102-1-1.html

/**
 * @author DX
 *         这种方案建议只在开发调试的时候使用，因为这将损耗一些性能(需要额外加载apk文件)，调试没问题后，直接修改xposed_init文件为正确的类即可
 *         可以实现免重启，由于存在缓存，需要杀死宿主程序以后才能生效
 *         这种免重启的方式针对某些特殊情况的hook无效
 *         例如我们需要implements IXposedHookZygoteInit,并将自己的一个服务注册为系统服务，这种就必须重启了
 *         Created by DX on 2017/10/4.
 */

public class HookLoader2 implements IXposedHookLoadPackage {
    //按照实际使用情况修改下面几项的值
    /**
     * 当前Xposed模块的包名,方便寻找apk文件
     */
    private final String modulePackage = "com.xxx.plugin";
    /**
     * 宿主程序的包名(允许多个),过滤无意义的包名,防止无意义的apk文件加载
     */
    private static List<String> hostAppPackages = new ArrayList<>();

    static {
        // TODO: Add the package name of application your want to hook!
        hostAppPackages.add("com.eg.android.AlipayGphone");
        hostAppPackages.add("com.xxx.plugin");
    }

    /**
     * 实际hook逻辑处理类
     */
    private final String handleHookClass = TargetHook.class.getName();
    /**
     * 实际hook逻辑处理类的入口方法
     */
    private final String handleHookMethod = "handleLoadPackage";

    @Override
    public void handleLoadPackage(final XC_LoadPackage.LoadPackageParam loadPackageParam) throws Throwable {
        if (hostAppPackages.contains(loadPackageParam.packageName)) {
            //将loadPackageParam的classloader替换为宿主程序Application的classloader,解决宿主程序存在多个.dex文件时,有时候ClassNotFound的问题
            XposedHelpers.findAndHookMethod(Application.class, "attach", Context.class, new XC_MethodHook() {
                @Override
                protected void afterHookedMethod(MethodHookParam param) throws Throwable {
                    Context context=(Context) param.args[0];
                    loadPackageParam.classLoader = context.getClassLoader();
                    invokeHandleHookMethod(context,modulePackage, handleHookClass, handleHookMethod, loadPackageParam);
                }
            });
        }
    }

    /**
     * 安装app以后，系统会在/data/app/下备份了一份.apk文件，通过动态加载这个apk文件，调用相应的方法
     * 这样就可以实现，只需要第一次重启，以后修改hook代码就不用重启了
     * @param context context参数
     * @param modulePackageName 当前模块的packageName
     * @param handleHookClass   指定由哪一个类处理相关的hook逻辑
     * @param loadPackageParam  传入XC_LoadPackage.LoadPackageParam参数
     * @throws Throwable 抛出各种异常,包括具体hook逻辑的异常,寻找apk文件异常,反射加载Class异常等
     */
    private void invokeHandleHookMethod(Context context, String modulePackageName, String handleHookClass, String handleHookMethod, XC_LoadPackage.LoadPackageParam loadPackageParam) throws Throwable {
        File apkFile=findApkFile(context,modulePackageName);
        if (apkFile==null){
            throw new RuntimeException("寻找模块apk失败");
        }
        //加载指定的hook逻辑处理类，并调用它的handleHook方法
        PathClassLoader pathClassLoader = new PathClassLoader(apkFile.getAbsolutePath(), ClassLoader.getSystemClassLoader());
        Class<?> cls = Class.forName(handleHookClass, true, pathClassLoader);
        Object instance = cls.newInstance();
        Method method = cls.getDeclaredMethod(handleHookMethod, XC_LoadPackage.LoadPackageParam.class);
        method.invoke(instance, loadPackageParam);
    }

    /**
     * 根据包名构建目标Context,并调用getPackageCodePath()来定位apk
     * @param context context参数
     * @param modulePackageName 当前模块包名
     * @return return apk file
     */
    private File findApkFile(Context context, String modulePackageName){
        if (context==null){
            return null;
        }
        try {
            Context moudleContext = context.createPackageContext(modulePackageName, Context.CONTEXT_INCLUDE_CODE | Context.CONTEXT_IGNORE_SECURITY);
            String apkPath=moudleContext.getPackageCodePath();
            return new File(apkPath);
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }
}