Merge "Refactor answer callback for async DNS query JAVA API" am: f1d0fd2642
am: 9a4c839725
Change-Id: I7538b247c5bd84d7f5b21be11b9bb1940fb9ba5a
diff --git a/api/current.txt b/api/current.txt
index 0cff056..aa50553 100755
--- a/api/current.txt
+++ b/api/current.txt
@@ -27225,10 +27225,9 @@
}
public final class DnsResolver {
- method public static android.net.DnsResolver getInstance();
- method public void query(@Nullable android.net.Network, @NonNull byte[], int, @NonNull android.os.Handler, @NonNull android.net.DnsResolver.RawAnswerListener) throws android.system.ErrnoException;
- method public void query(@Nullable android.net.Network, @NonNull String, int, int, int, @NonNull android.os.Handler, @NonNull android.net.DnsResolver.RawAnswerListener) throws android.system.ErrnoException;
- method public void query(@Nullable android.net.Network, @NonNull String, int, @NonNull android.os.Handler, @NonNull android.net.DnsResolver.InetAddressAnswerListener) throws android.system.ErrnoException;
+ method @NonNull public static android.net.DnsResolver getInstance();
+ method public <T> void query(@Nullable android.net.Network, @NonNull byte[], int, @NonNull android.os.Handler, @NonNull android.net.DnsResolver.AnswerCallback<T>);
+ method public <T> void query(@Nullable android.net.Network, @NonNull String, int, int, int, @NonNull android.os.Handler, @NonNull android.net.DnsResolver.AnswerCallback<T>);
field public static final int CLASS_IN = 1; // 0x1
field public static final int FLAG_EMPTY = 0; // 0x0
field public static final int FLAG_NO_CACHE_LOOKUP = 4; // 0x4
@@ -27238,12 +27237,23 @@
field public static final int TYPE_AAAA = 28; // 0x1c
}
- public static interface DnsResolver.InetAddressAnswerListener {
- method public void onAnswer(@NonNull java.util.List<java.net.InetAddress>);
+ public abstract static class DnsResolver.AnswerCallback<T> {
+ ctor public DnsResolver.AnswerCallback(@NonNull android.net.DnsResolver.AnswerParser<T>);
+ method public abstract void onAnswer(@NonNull T);
+ method public abstract void onParseException(@NonNull android.net.ParseException);
+ method public abstract void onQueryException(@NonNull android.system.ErrnoException);
}
- public static interface DnsResolver.RawAnswerListener {
- method public void onAnswer(@Nullable byte[]);
+ public static interface DnsResolver.AnswerParser<T> {
+ method @NonNull public T parse(@NonNull byte[]) throws android.net.ParseException;
+ }
+
+ public abstract static class DnsResolver.InetAddressAnswerCallback extends android.net.DnsResolver.AnswerCallback<java.util.List<java.net.InetAddress>> {
+ ctor public DnsResolver.InetAddressAnswerCallback();
+ }
+
+ public abstract static class DnsResolver.RawAnswerCallback extends android.net.DnsResolver.AnswerCallback<byte[]> {
+ ctor public DnsResolver.RawAnswerCallback();
}
public class InetAddresses {
@@ -27557,6 +27567,8 @@
}
public class ParseException extends java.lang.RuntimeException {
+ ctor public ParseException(@NonNull String);
+ ctor public ParseException(@NonNull String, @NonNull Throwable);
field public String response;
}
diff --git a/core/java/android/net/DnsPacket.java b/core/java/android/net/DnsPacket.java
index 0ac02b1..83e57e0 100644
--- a/core/java/android/net/DnsPacket.java
+++ b/core/java/android/net/DnsPacket.java
@@ -71,7 +71,7 @@
}
/**
- * It's used both for DNS questions and DNS resource records.
+ * Superclass for DNS questions and DNS resource records.
*
* DNS questions (No TTL/RDATA)
* DNS resource records (With TTL/RDATA)
@@ -96,12 +96,13 @@
/**
* Create a new DnsRecord from a positioned ByteBuffer.
*
- * @param ByteBuffer input of record, must be in network byte order
- * (which is the default).
* Reads the passed ByteBuffer from its current position and decodes a DNS record.
* When this constructor returns, the reading position of the ByteBuffer has been
* advanced to the end of the DNS header record.
* This is meant to chain with other methods reading a DNS response in sequence.
+ *
+ * @param ByteBuffer input of record, must be in network byte order
+ * (which is the default).
*/
DnsRecord(int recordType, @NonNull ByteBuffer buf)
throws BufferUnderflowException, ParseException {
@@ -205,16 +206,6 @@
protected final DnsHeader mHeader;
protected final List<DnsRecord>[] mRecords;
- public static class ParseException extends Exception {
- public ParseException(String msg) {
- super(msg);
- }
-
- public ParseException(String msg, Throwable cause) {
- super(msg, cause);
- }
- }
-
protected DnsPacket(@NonNull byte[] data) throws ParseException {
if (null == data) throw new ParseException("Parse header failed, null input data");
final ByteBuffer buffer;
diff --git a/core/java/android/net/DnsResolver.java b/core/java/android/net/DnsResolver.java
index d3bc3e6..f248958 100644
--- a/core/java/android/net/DnsResolver.java
+++ b/core/java/android/net/DnsResolver.java
@@ -37,8 +37,6 @@
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
-import java.util.function.Consumer;
-
/**
* Dns resolver class for asynchronous dns querying
@@ -81,66 +79,138 @@
public static final int FLAG_NO_CACHE_STORE = 1 << 1;
public static final int FLAG_NO_CACHE_LOOKUP = 1 << 2;
- private static final int DNS_RAW_RESPONSE = 1;
-
private static final int NETID_UNSET = 0;
private static final DnsResolver sInstance = new DnsResolver();
/**
- * listener for receiving raw answers
- */
- public interface RawAnswerListener {
- /**
- * {@code byte[]} is {@code null} if query timed out
- */
- void onAnswer(@Nullable byte[] answer);
- }
-
- /**
- * listener for receiving parsed answers
- */
- public interface InetAddressAnswerListener {
- /**
- * Will be called exactly once with all the answers to the query.
- * size of addresses will be zero if no available answer could be parsed.
- */
- void onAnswer(@NonNull List<InetAddress> addresses);
- }
-
- /**
* Get instance for DnsResolver
*/
- public static DnsResolver getInstance() {
+ public static @NonNull DnsResolver getInstance() {
return sInstance;
}
private DnsResolver() {}
/**
- * Pass in a blob and corresponding setting,
- * get a blob back asynchronously with the entire raw answer.
+ * Answer parser for parsing raw answers
+ *
+ * @param <T> The type of the parsed answer
+ */
+ public interface AnswerParser<T> {
+ /**
+ * Creates a <T> answer by parsing the given raw answer.
+ *
+ * @param rawAnswer the raw answer to be parsed
+ * @return a parsed <T> answer
+ * @throws ParseException if parsing failed
+ */
+ @NonNull T parse(@NonNull byte[] rawAnswer) throws ParseException;
+ }
+
+ /**
+ * Base class for answer callbacks
+ *
+ * @param <T> The type of the parsed answer
+ */
+ public abstract static class AnswerCallback<T> {
+ /** @hide */
+ public final AnswerParser<T> parser;
+
+ public AnswerCallback(@NonNull AnswerParser<T> parser) {
+ this.parser = parser;
+ };
+
+ /**
+ * Success response to
+ * {@link android.net.DnsResolver#query query()}.
+ *
+ * Invoked when the answer to a query was successfully parsed.
+ *
+ * @param answer parsed answer to the query.
+ *
+ * {@see android.net.DnsResolver#query query()}
+ */
+ public abstract void onAnswer(@NonNull T answer);
+
+ /**
+ * Error response to
+ * {@link android.net.DnsResolver#query query()}.
+ *
+ * Invoked when there is no valid answer to
+ * {@link android.net.DnsResolver#query query()}
+ *
+ * @param exception a {@link ParseException} object with additional
+ * detail regarding the failure
+ */
+ public abstract void onParseException(@NonNull ParseException exception);
+
+ /**
+ * Error response to
+ * {@link android.net.DnsResolver#query query()}.
+ *
+ * Invoked if an error happens when
+ * issuing the DNS query or receiving the result.
+ * {@link android.net.DnsResolver#query query()}
+ *
+ * @param exception an {@link ErrnoException} object with additional detail
+ * regarding the failure
+ */
+ public abstract void onQueryException(@NonNull ErrnoException exception);
+ }
+
+ /**
+ * Callback for receiving raw answers
+ */
+ public abstract static class RawAnswerCallback extends AnswerCallback<byte[]> {
+ public RawAnswerCallback() {
+ super(rawAnswer -> rawAnswer);
+ }
+ }
+
+ /**
+ * Callback for receiving parsed {@link InetAddress} answers
+ *
+ * Note that if the answer does not contain any IP addresses,
+ * onAnswer will be called with an empty list.
+ */
+ public abstract static class InetAddressAnswerCallback
+ extends AnswerCallback<List<InetAddress>> {
+ public InetAddressAnswerCallback() {
+ super(rawAnswer -> new DnsAddressAnswer(rawAnswer).getAddresses());
+ }
+ }
+
+ /**
+ * Pass in a blob and corresponding flags, get an answer back asynchronously
+ * through {@link AnswerCallback}.
*
* @param network {@link Network} specifying which network for querying.
* {@code null} for query on default network.
* @param query blob message
* @param flags flags as a combination of the FLAGS_* constants
* @param handler {@link Handler} to specify the thread
- * upon which the {@link RawAnswerListener} will be invoked.
- * @param listener a {@link RawAnswerListener} which will be called to notify the caller
+ * upon which the {@link AnswerCallback} will be invoked.
+ * @param callback an {@link AnswerCallback} which will be called to notify the caller
* of the result of dns query.
*/
- public void query(@Nullable Network network, @NonNull byte[] query, @QueryFlag int flags,
- @NonNull Handler handler, @NonNull RawAnswerListener listener) throws ErrnoException {
- final FileDescriptor queryfd = resNetworkSend((network != null
+ public <T> void query(@Nullable Network network, @NonNull byte[] query, @QueryFlag int flags,
+ @NonNull Handler handler, @NonNull AnswerCallback<T> callback) {
+ final FileDescriptor queryfd;
+ try {
+ queryfd = resNetworkSend((network != null
? network.netId : NETID_UNSET), query, query.length, flags);
- registerFDListener(handler.getLooper().getQueue(), queryfd,
- answerbuf -> listener.onAnswer(answerbuf));
+ } catch (ErrnoException e) {
+ callback.onQueryException(e);
+ return;
+ }
+
+ registerFDListener(handler.getLooper().getQueue(), queryfd, callback);
}
/**
- * Pass in a domain name and corresponding setting,
- * get a blob back asynchronously with the entire raw answer.
+ * Pass in a domain name and corresponding setting, get an answer back asynchronously
+ * through {@link AnswerCallback}.
*
* @param network {@link Network} specifying which network for querying.
* {@code null} for query on default network.
@@ -149,52 +219,26 @@
* @param nsType dns resource record (RR) type as one of the TYPE_* constants
* @param flags flags as a combination of the FLAGS_* constants
* @param handler {@link Handler} to specify the thread
- * upon which the {@link RawAnswerListener} will be invoked.
- * @param listener a {@link RawAnswerListener} which will be called to notify the caller
+ * upon which the {@link AnswerCallback} will be invoked.
+ * @param callback an {@link AnswerCallback} which will be called to notify the caller
* of the result of dns query.
*/
- public void query(@Nullable Network network, @NonNull String domain, @QueryClass int nsClass,
- @QueryType int nsType, @QueryFlag int flags,
- @NonNull Handler handler, @NonNull RawAnswerListener listener) throws ErrnoException {
- final FileDescriptor queryfd = resNetworkQuery((network != null
- ? network.netId : NETID_UNSET), domain, nsClass, nsType, flags);
- registerFDListener(handler.getLooper().getQueue(), queryfd,
- answerbuf -> listener.onAnswer(answerbuf));
+ public <T> void query(@Nullable Network network, @NonNull String domain,
+ @QueryClass int nsClass, @QueryType int nsType, @QueryFlag int flags,
+ @NonNull Handler handler, @NonNull AnswerCallback<T> callback) {
+ final FileDescriptor queryfd;
+ try {
+ queryfd = resNetworkQuery((network != null
+ ? network.netId : NETID_UNSET), domain, nsClass, nsType, flags);
+ } catch (ErrnoException e) {
+ callback.onQueryException(e);
+ return;
+ }
+ registerFDListener(handler.getLooper().getQueue(), queryfd, callback);
}
- /**
- * Pass in a domain name and corresponding setting,
- * get back a set of InetAddresses asynchronously.
- *
- * @param network {@link Network} specifying which network for querying.
- * {@code null} for query on default network.
- * @param domain domain name for querying
- * @param flags flags as a combination of the FLAGS_* constants
- * @param handler {@link Handler} to specify the thread
- * upon which the {@link InetAddressAnswerListener} will be invoked.
- * @param listener an {@link InetAddressAnswerListener} which will be called to
- * notify the caller of the result of dns query.
- *
- */
- public void query(@Nullable Network network, @NonNull String domain, @QueryFlag int flags,
- @NonNull Handler handler, @NonNull InetAddressAnswerListener listener)
- throws ErrnoException {
- final FileDescriptor v4fd = resNetworkQuery((network != null
- ? network.netId : NETID_UNSET), domain, CLASS_IN, TYPE_A, flags);
- final FileDescriptor v6fd = resNetworkQuery((network != null
- ? network.netId : NETID_UNSET), domain, CLASS_IN, TYPE_AAAA, flags);
-
- final InetAddressAnswerAccumulator accmulator =
- new InetAddressAnswerAccumulator(2, listener);
- final Consumer<byte[]> consumer = answerbuf ->
- accmulator.accumulate(parseAnswers(answerbuf));
-
- registerFDListener(handler.getLooper().getQueue(), v4fd, consumer);
- registerFDListener(handler.getLooper().getQueue(), v6fd, consumer);
- }
-
- private void registerFDListener(@NonNull MessageQueue queue,
- @NonNull FileDescriptor queryfd, @NonNull Consumer<byte[]> answerConsumer) {
+ private <T> void registerFDListener(@NonNull MessageQueue queue,
+ @NonNull FileDescriptor queryfd, @NonNull AnswerCallback<T> answerCallback) {
queue.addOnFileDescriptorEventListener(
queryfd,
FD_EVENTS,
@@ -207,15 +251,22 @@
answerbuf = resNetworkResult(fd);
} catch (ErrnoException e) {
Log.e(TAG, "resNetworkResult:" + e.toString());
+ answerCallback.onQueryException(e);
+ return 0;
}
- answerConsumer.accept(answerbuf);
+
+ try {
+ answerCallback.onAnswer(answerCallback.parser.parse(answerbuf));
+ } catch (ParseException e) {
+ answerCallback.onParseException(e);
+ }
// Unregister this fd listener
return 0;
});
}
- private class DnsAddressAnswer extends DnsPacket {
+ private static class DnsAddressAnswer extends DnsPacket {
private static final String TAG = "DnsResolver.DnsAddressAnswer";
private static final boolean DBG = false;
@@ -226,12 +277,6 @@
if ((mHeader.flags & (1 << 15)) == 0) {
throw new ParseException("Not an answer packet");
}
- if (mHeader.rcode != 0) {
- throw new ParseException("Response error, rcode:" + mHeader.rcode);
- }
- if (mHeader.getRecordCount(ANSECTION) == 0) {
- throw new ParseException("No available answer");
- }
if (mHeader.getRecordCount(QDSECTION) == 0) {
throw new ParseException("No question found");
}
@@ -241,6 +286,8 @@
public @NonNull List<InetAddress> getAddresses() {
final List<InetAddress> results = new ArrayList<InetAddress>();
+ if (mHeader.getRecordCount(ANSECTION) == 0) return results;
+
for (final DnsRecord ansSec : mRecords[ANSECTION]) {
// Only support A and AAAA, also ignore answers if query type != answer type.
int nsType = ansSec.nsType;
@@ -259,34 +306,4 @@
}
}
- private @Nullable List<InetAddress> parseAnswers(@Nullable byte[] data) {
- try {
- return (data == null) ? null : new DnsAddressAnswer(data).getAddresses();
- } catch (DnsPacket.ParseException e) {
- Log.e(TAG, "Parse answer fail " + e.getMessage());
- return null;
- }
- }
-
- private class InetAddressAnswerAccumulator {
- private final List<InetAddress> mAllAnswers;
- private final InetAddressAnswerListener mAnswerListener;
- private final int mTargetAnswerCount;
- private int mReceivedAnswerCount = 0;
-
- InetAddressAnswerAccumulator(int size, @NonNull InetAddressAnswerListener listener) {
- mTargetAnswerCount = size;
- mAllAnswers = new ArrayList<>();
- mAnswerListener = listener;
- }
-
- public void accumulate(@Nullable List<InetAddress> answer) {
- if (null != answer) {
- mAllAnswers.addAll(answer);
- }
- if (++mReceivedAnswerCount == mTargetAnswerCount) {
- mAnswerListener.onAnswer(mAllAnswers);
- }
- }
- }
}
diff --git a/core/java/android/net/ParseException.java b/core/java/android/net/ParseException.java
index 2380e86..9d4727a 100644
--- a/core/java/android/net/ParseException.java
+++ b/core/java/android/net/ParseException.java
@@ -16,15 +16,22 @@
package android.net;
+import android.annotation.NonNull;
+
/**
- * Thrown when parsing a URL fails.
+ * Thrown when parsing failed.
*/
// See non-public class {@link WebAddress}.
public class ParseException extends RuntimeException {
public String response;
- ParseException(String response) {
+ public ParseException(@NonNull String response) {
super(response);
this.response = response;
}
+
+ public ParseException(@NonNull String response, @NonNull Throwable cause) {
+ super(response, cause);
+ this.response = response;
+ }
}
diff --git a/tests/net/java/android/net/DnsPacketTest.java b/tests/net/java/android/net/DnsPacketTest.java
index 9ede2b8..975abf4 100644
--- a/tests/net/java/android/net/DnsPacketTest.java
+++ b/tests/net/java/android/net/DnsPacketTest.java
@@ -69,7 +69,7 @@
try {
new TestDnsPacket(null);
fail("Exception not thrown for null byte array");
- } catch (DnsPacket.ParseException e) {
+ } catch (ParseException e) {
}
}