ARouter源码解析06-openDebug

忘是亡心i 2023-10-17 14:36 17阅读 0赞

如果我们的Android Studio使用了 instant run ，ARouter的跳转会失效，这种情况下我们需要开init之前，调用openDebug。(仅限于debug环境，正式版本有安全风险)

// 调试模式不是必须开启，但是为了防止有用户开启了InstantRun，但是
    // 忘了开调试模式，导致无法使用Demo，如果使用了InstantRun，必须在
    // 初始化之前开启调试模式，但是上线前需要关闭，InstantRun仅用于开
    // 发阶段，线上开启调试模式有安全风险，可以使用BuildConfig.DEBUG
    // 来区分环境
    ARouter.openDebug();
    ARouter.init(getApplication());

那么，在openDebug()中做了什么呢？

ARouter.openDebug()只是将debuggable这个标记置为了true

static synchronized void openDebug() {
        debuggable = true;
        logger.info(Consts.TAG, "ARouter openDebug");
    }

那么什么时候会去使用这个标记呢 ？ 我们继续来追踪发现， 在获取sourcePath时，ARouter会调用tryLoadInstantRunDexFile将instant run 的 dex 文件 加入到 sourcePaths 中并返回。即如果debuggable这个标记为true，就会把instant run 的 dex 文件下的sourcepath也获取到。

public class ClassUtils {
        public static List<String> getSourcePaths(Context context) throws PackageManager.NameNotFoundException, IOException {
            ApplicationInfo applicationInfo = context.getPackageManager().getApplicationInfo(context.getPackageName(), 0);
            File sourceApk = new File(applicationInfo.sourceDir);
    
            List<String> sourcePaths = new ArrayList<>();
            sourcePaths.add(applicationInfo.sourceDir); //add the default apk path
    
            //the prefix of extracted file, ie: test.classes
            String extractedFilePrefix = sourceApk.getName() + EXTRACTED_NAME_EXT;
    
            //如果VM已经支持了MultiDex，就不要去Secondary Folder加载 Classesx.zip了，那里已经么有了
            //通过是否存在sp中的multidex.version是不准确的，因为从低版本升级上来的用户，是包含这个sp配置的
            if (!isVMMultidexCapable()) {
                //the total dex numbers
                int totalDexNumber = getMultiDexPreferences(context).getInt(KEY_DEX_NUMBER, 1);
                File dexDir = new File(applicationInfo.dataDir, SECONDARY_FOLDER_NAME);
    
                for (int secondaryNumber = 2; secondaryNumber <= totalDexNumber; secondaryNumber++) {
                    //for each dex file, ie: test.classes2.zip, test.classes3.zip...
                    String fileName = extractedFilePrefix + secondaryNumber + EXTRACTED_SUFFIX;
                    File extractedFile = new File(dexDir, fileName);
                    if (extractedFile.isFile()) {
                        sourcePaths.add(extractedFile.getAbsolutePath());
                        //we ignore the verify zip part
                    } else {
                        throw new IOException("Missing extracted secondary dex file '" + extractedFile.getPath() + "'");
                    }
                }
            }
    
            if (ARouter.debuggable()) { // Search instant run support only debuggable
                sourcePaths.addAll(tryLoadInstantRunDexFile(applicationInfo));
            }
            return sourcePaths;
        }
    
        /**
         * Get instant run dex path, used to catch the branch usingApkSplits=false.
         */
        private static List<String> tryLoadInstantRunDexFile(ApplicationInfo applicationInfo) {
            List<String> instantRunSourcePaths = new ArrayList<>();
    
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && null != applicationInfo.splitSourceDirs) {
                // add the splite apk, normally for InstantRun, and newest version.
                instantRunSourcePaths.addAll(Arrays.asList(applicationInfo.splitSourceDirs));
                Log.d("ARouter", "Found InstantRun support");
            } else {
                try {
                    // This man is reflection from Google instant run sdk, he will tell me where the dex files go.
                    Class pathsByInstantRun = Class.forName("com.android.tools.fd.runtime.Paths");
                    Method getDexFileDirectory = pathsByInstantRun.getMethod("getDexFileDirectory", String.class);
                    String instantRunDexPath = (String) getDexFileDirectory.invoke(null, applicationInfo.packageName);
    
                    File instantRunFilePath = new File(instantRunDexPath);
                    if (instantRunFilePath.exists() && instantRunFilePath.isDirectory()) {
                        File[] dexFile = instantRunFilePath.listFiles();
                        for (File file : dexFile) {
                            if (null != file && file.exists() && file.isFile() && file.getName().endsWith(".dex")) {
                                instantRunSourcePaths.add(file.getAbsolutePath());
                            }
                        }
                        Log.d("ARouter", "Found InstantRun support");
                    }
    
                } catch (Exception e) {
                    Log.e("ARouter", "InstantRun support error, " + e.getMessage());
                }
            }
    
            return instantRunSourcePaths;
        }
    }

至此，我们就分析完openDebug了。