API review: access field by method

- InvalidPacketException, public field should be a method so
  add getter to get error code.
- KeepalivePacketData, public fields should be methods so
   add getter for fields.

Bug: 151322799
Test: atest FrameworksNetTests
      atest FrameworksWifiTests
      atest FrameworksTelephonyTests: some failure in CarrierAppUtilsTest
Change-Id: Id01e6135193716cc21bba11da529bf1507a954f7

core/java/android/net/InvalidPacketException.java

@@ -28,7 +28,7 @@ import java.lang.annotation.RetentionPolicy;
  */
 @SystemApi
 public class InvalidPacketException extends Exception {
-    public final int error;
+    private final int mError;
 
     // Must match SocketKeepalive#ERROR_INVALID_IP_ADDRESS.
     /** Invalid IP address. */
@@ -56,6 +56,11 @@ public class InvalidPacketException extends Exception {
      * See the error code for details.
      */
     public InvalidPacketException(@ErrorCode final int error) {
-        this.error = error;
+        this.mError = error;
+    }
+
+    /** Get error code. */
+    public int getError() {
+        return mError;
     }
 }

core/java/android/net/KeepalivePacketData.java

@@ -19,6 +19,7 @@ package android.net;
 import static android.net.InvalidPacketException.ERROR_INVALID_IP_ADDRESS;
 import static android.net.InvalidPacketException.ERROR_INVALID_PORT;
 
+import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.net.util.IpUtils;
@@ -37,17 +38,17 @@ public class KeepalivePacketData {
 
     /** Source IP address */
     @NonNull
-    public final InetAddress srcAddress;
+    private final InetAddress mSrcAddress;
 
     /** Destination IP address */
     @NonNull
-    public final InetAddress dstAddress;
+    private final InetAddress mDstAddress;
 
     /** Source port */
-    public final int srcPort;
+    private final int mSrcPort;
 
     /** Destination port */
-    public final int dstPort;
+    private final int mDstPort;
 
     /** Packet data. A raw byte string of packet data, not including the link-layer header. */
     private final byte[] mPacket;
@@ -60,13 +61,14 @@ public class KeepalivePacketData {
     /**
      * A holding class for data necessary to build a keepalive packet.
      */
-    protected KeepalivePacketData(@NonNull InetAddress srcAddress, int srcPort,
-            @NonNull InetAddress dstAddress, int dstPort,
-                    @NonNull byte[] data) throws InvalidPacketException {
-        this.srcAddress = srcAddress;
-        this.dstAddress = dstAddress;
-        this.srcPort = srcPort;
-        this.dstPort = dstPort;
+    protected KeepalivePacketData(@NonNull InetAddress srcAddress,
+            @IntRange(from = 0, to = 65535) int srcPort, @NonNull InetAddress dstAddress,
+            @IntRange(from = 0, to = 65535) int dstPort,
+            @NonNull byte[] data) throws InvalidPacketException {
+        this.mSrcAddress = srcAddress;
+        this.mDstAddress = dstAddress;
+        this.mSrcPort = srcPort;
+        this.mDstPort = dstPort;
         this.mPacket = data;
 
         // Check we have two IP addresses of the same family.
@@ -83,6 +85,31 @@ public class KeepalivePacketData {
         }
     }
 
+    /** Get source IP address. */
+    @NonNull
+    public InetAddress getSrcAddress() {
+        return mSrcAddress;
+    }
+
+    /** Get destination IP address. */
+    @NonNull
+    public InetAddress getDstAddress() {
+        return mDstAddress;
+    }
+
+    /** Get source port number. */
+    public int getSrcPort() {
+        return mSrcPort;
+    }
+
+    /** Get destination port number. */
+    public int getDstPort() {
+        return mDstPort;
+    }
+
+    /**
+     * Returns a byte array of the given packet data.
+     */
     @NonNull
     public byte[] getPacket() {
         return mPacket.clone();

core/java/android/net/NattKeepalivePacketData.java

@@ -94,10 +94,10 @@ public final class NattKeepalivePacketData extends KeepalivePacketData implement
 
     /** Write to parcel */
     public void writeToParcel(@NonNull Parcel out, int flags) {
-        out.writeString(srcAddress.getHostAddress());
-        out.writeString(dstAddress.getHostAddress());
-        out.writeInt(srcPort);
-        out.writeInt(dstPort);
+        out.writeString(getSrcAddress().getHostAddress());
+        out.writeString(getDstAddress().getHostAddress());
+        out.writeInt(getSrcPort());
+        out.writeInt(getDstPort());
     }
 
     /** Parcelable Creator */
@@ -115,7 +115,7 @@ public final class NattKeepalivePacketData extends KeepalivePacketData implement
                                     dstAddress, dstPort);
                     } catch (InvalidPacketException e) {
                         throw new IllegalArgumentException(
-                                "Invalid NAT-T keepalive data: " + e.error);
+                                "Invalid NAT-T keepalive data: " + e.getError());
                     }
                 }
 
@@ -128,14 +128,16 @@ public final class NattKeepalivePacketData extends KeepalivePacketData implement
     public boolean equals(@Nullable final Object o) {
         if (!(o instanceof NattKeepalivePacketData)) return false;
         final NattKeepalivePacketData other = (NattKeepalivePacketData) o;
-        return this.srcAddress.equals(other.srcAddress)
-            && this.dstAddress.equals(other.dstAddress)
-            && this.srcPort == other.srcPort
-            && this.dstPort == other.dstPort;
+        final InetAddress srcAddress = getSrcAddress();
+        final InetAddress dstAddress = getDstAddress();
+        return srcAddress.equals(other.getSrcAddress())
+            && dstAddress.equals(other.getDstAddress())
+            && getSrcPort() == other.getSrcPort()
+            && getDstPort() == other.getDstPort();
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(srcAddress, dstAddress, srcPort, dstPort);
+        return Objects.hash(getSrcAddress(), getDstAddress(), getSrcPort(), getDstPort());
     }
 }