怎么在smali中修改才能注释java代码中的一行

Posted 2023-04-12

参考技术A i want to delete the 580th and 581th line in the java code below. this file is in system/framework/services.jar in android devices, so the steps i did are:
1. decompile jar to smali
2. change the smali file
3. recompile the smali file to dex file
4. pack it into services.jar.
5. push services.jar into android mobile phone
The question is on step2, how to change the smali file, i try to delete :line580 and the code below it, but it doesn"t work, when compiling, a nullPointerExecption thrown...and i can see /*error*/ in jd-gui tool
Somebody please give me some advices, i"m totally new to smali, thanks in advance.
100分相送，望大神指点，谢谢

The java code is:

568 public void registerUiTestAutomationService(IBinder owner,
569 IAccessibilityServiceClient serviceClient,
570 AccessibilityServiceInfo accessibilityServiceInfo)
571 mSecurityPolicy.enforceCallingPermission(Manifest.permission.RETRIEVE_WINDOW_CONTENT,
572 FUNCTION_REGISTER_UI_TEST_AUTOMATION_SERVICE);
573
574 accessibilityServiceInfo.setComponentName(sFakeAccessibilityServiceComponentName);
575
576 synchronized (mLock)
577 UserState userState = getCurrentUserStateLocked();
578
579 if (userState.mUiAutomationService != null)
580 throw new IllegalStateException("UiAutomationService " + serviceClient
581 + "already registered!");
582
583
584 try
585 owner.linkToDeath(userState.mUiAutomationSerivceOnwerDeathRecipient, 0);
586 catch (RemoteException re)
587 Slog.e(LOG_TAG, "Couldn"t register for the death of a"
588 + " UiTestAutomationService!", re);
589 return;
590
591
592 userState.mUiAutomationServiceOwner = owner;
593 userState.mUiAutomationServiceClient = serviceClient;
594
595 // Set the temporary state.
596 userState.mIsAccessibilityEnabled = true;
597 userState.mIsTouchExplorationEnabled = false;
598 userState.mIsEnhancedWebAccessibilityEnabled = false;
599 userState.mIsDisplayMagnificationEnabled = false;
600 userState.mInstalledServices.add(accessibilityServiceInfo);
601 userState.mEnabledServices.clear();
602 userState.mEnabledServices.add(sFakeAccessibilityServiceComponentName);
603 userState.mTouchExplorationGrantedServices.add(sFakeAccessibilityServiceComponentName);
604
605 // Use the new state instead of settings.
606 onUserStateChangedLocked(userState);
607
608

The smali code after decompiling:

.line 579
.local v1, "userState":Lcom/android/server/accessibility/AccessibilityManagerService$UserState;
# getter for: Lcom/android/server/accessibility/AccessibilityManagerService$UserState;->mUiAutomationService:Lcom/android/server/accessibility/AccessibilityManagerService$Service;
invoke-static v1, Lcom/android/server/accessibility/AccessibilityManagerService$UserState;->access$300(Lcom/android/server/accessibility/AccessibilityManagerService$UserState;)Lcom/android/server/accessibility/AccessibilityManagerService$Service;

move-result-object v2

if-eqz v2, :cond_3d

.line 580
new-instance v2, Ljava/lang/IllegalStateException;

new-instance v4, Ljava/lang/StringBuilder;

invoke-direct v4, Ljava/lang/StringBuilder;-><init>()V

const-string v5, "UiAutomationService "

invoke-virtual v4, v5, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;

move-result-object v4

invoke-virtual v4, p2, Ljava/lang/StringBuilder;->append(Ljava/lang/Object;)Ljava/lang/StringBuilder;

move-result-object v4

const-string v5, "already registered!"

invoke-virtual v4, v5, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;

move-result-object v4

invoke-virtual v4, Ljava/lang/StringBuilder;->toString()Ljava/lang/String;

move-result-object v4

invoke-direct v2, v4, Ljava/lang/IllegalStateException;-><init>(Ljava/lang/String;)V

throw v2

.line 607
.end local v1 # "userState":Lcom/android/server/accessibility/AccessibilityManagerService$UserState;
:catchall_3a
move-exception v2

monitor-exit v3
:try_end_3c
.catchall :try_start_11 .. :try_end_3c :catchall_3a

throw v2

.line 585
.restart local v1 # "userState":Lcom/android/server/accessibility/AccessibilityManagerService$UserState;
:cond_3d
:try_start_3d
# getter for: Lcom/android/server/accessibility/AccessibilityManagerService$UserState;->mUiAutomationSerivceOnwerDeathRecipient:Landroid/os/IBinder$DeathRecipient;
invoke-static v1, Lcom/android/server/accessibility/AccessibilityManagerService$UserState;->access$1200(Lcom/android/server/accessibility/AccessibilityManagerService$UserState;)Landroid/os/IBinder$DeathRecipient;

move-result-object v2

const/4 v4, 0x0

invoke-interface p1, v2, v4, Landroid/os/IBinder;->linkToDeath(Landroid/os/IBinder$DeathRecipient;I)V
:try_end_45
.catch Landroid/os/RemoteException; :try_start_3d .. :try_end_45 :catch_74
.catchall :try_start_3d .. :try_end_45 :catchall_3a
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