Enforce non-nullness in PrinterId and exploit it.

Change-Id: Ifdf3b2329548a665d609dd66b738baab5c765b54

2 files changed, 15 insertions, 16 deletions

diff --git a/core/java/android/print/PrinterId.java b/core/java/android/print/PrinterId.java
index 83efe8020d98..ff9c0df58f91 100644
--- a/core/java/android/print/PrinterId.java
+++ b/core/java/android/print/PrinterId.java
@@ -20,16 +20,17 @@ import android.annotation.NonNull;
 import android.content.ComponentName;
 import android.os.Parcel;
 import android.os.Parcelable;
-import android.text.TextUtils;
+
+import com.android.internal.util.Preconditions;
 
 /**
  * This class represents the unique id of a printer.
  */
 public final class PrinterId implements Parcelable {
 
-    private final ComponentName mServiceName;
+    private final @NonNull ComponentName mServiceName;
 
-    private final String mLocalId;
+    private final @NonNull String mLocalId;
 
     /**
      * Creates a new instance.
@@ -39,14 +40,14 @@ public final class PrinterId implements Parcelable {
      *
      * @hide
      */
-    public PrinterId(ComponentName serviceName, String localId) {
+    public PrinterId(@NonNull ComponentName serviceName, @NonNull String localId) {
         mServiceName = serviceName;
         mLocalId = localId;
     }
 
-    private PrinterId(Parcel parcel) {
-        mServiceName = parcel.readParcelable(null);
-        mLocalId = parcel.readString();
+    private PrinterId(@NonNull Parcel parcel) {
+        mServiceName = Preconditions.checkNotNull((ComponentName) parcel.readParcelable(null));
+        mLocalId = Preconditions.checkNotNull(parcel.readString());
     }
 
     /**
@@ -56,7 +57,7 @@ public final class PrinterId implements Parcelable {
      *
      * @hide
      */
-    public ComponentName getServiceName() {
+    public @NonNull ComponentName getServiceName() {
         return mServiceName;
     }
 
@@ -93,14 +94,10 @@ public final class PrinterId implements Parcelable {
             return false;
         }
         PrinterId other = (PrinterId) object;
-        if (mServiceName == null) {
-            if (other.mServiceName != null) {
-                return false;
-            }
-        } else if (!mServiceName.equals(other.mServiceName)) {
+        if (!mServiceName.equals(other.mServiceName)) {
             return false;
         }
-        if (!TextUtils.equals(mLocalId, other.mLocalId)) {
+        if (!mLocalId.equals(other.mLocalId)) {
             return false;
         }
         return true;
@@ -110,8 +107,7 @@ public final class PrinterId implements Parcelable {
     public int hashCode() {
         final int prime = 31;
         int hashCode = 1;
-        hashCode = prime * hashCode + ((mServiceName != null)
-                ? mServiceName.hashCode() : 1);
+        hashCode = prime * hashCode + mServiceName.hashCode();
         hashCode = prime * hashCode + mLocalId.hashCode();
         return hashCode;
     }
diff --git a/core/java/android/printservice/PrintService.java b/core/java/android/printservice/PrintService.java
index d0037b762560..310449222a0b 100644
--- a/core/java/android/printservice/PrintService.java
+++ b/core/java/android/printservice/PrintService.java
@@ -30,6 +30,8 @@ import android.print.PrintJobInfo;
 import android.print.PrinterId;
 import android.util.Log;
 
+import com.android.internal.util.Preconditions;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -346,6 +348,7 @@ public abstract class PrintService extends Service {
      */
     public final PrinterId generatePrinterId(String localId) {
         throwIfNotCalledOnMainThread();
+        localId = Preconditions.checkNotNull(localId, "localId cannot be null");
         return new PrinterId(new ComponentName(getPackageName(),
                 getClass().getName()), localId);
     }