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Make parser more tolerant per #229
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- allow missing data fields
- if an AltBeacon parser fails, don't crash with NPE
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@davidgyoung
davidgyoung committed Jul 6, 2015
1 parent d4086c6 commit f2c0546
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Showing 3 changed files with 94 additions and 45 deletions.
89 changes: 45 additions & 44 deletions src/main/java/org/altbeacon/beacon/BeaconParser.java
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Original file line number Diff line number Diff line change
Expand Up @@ -407,7 +407,7 @@ protected Beacon fromScanData(byte[] bytesToProcess, int rssi, BluetoothDevice d
bytesToHex(bytesToProcess));
}
}

parseFailed = true;
beacon = null;
} else {
if (LogManager.isVerboseLoggingEnabled()) {
Expand All @@ -416,63 +416,64 @@ protected Beacon fromScanData(byte[] bytesToProcess, int rssi, BluetoothDevice d
}
}

for (int i = 0; i < mIdentifierEndOffsets.size(); i++) {
int endIndex = mIdentifierEndOffsets.get(i) + startByte;
if (endIndex > pduToParse.getEndIndex()) {
parseFailed = true;
if (LogManager.isVerboseLoggingEnabled()) {
LogManager.d(TAG, "Cannot parse identifier "+i+" because PDU is too short. endIndex: " + endIndex + " PDU endIndex: " + pduToParse.getEndIndex());
if (patternFound) {
for (int i = 0; i < mIdentifierEndOffsets.size(); i++) {
int endIndex = mIdentifierEndOffsets.get(i) + startByte;
if (endIndex > pduToParse.getEndIndex()) {
parseFailed = true;
if (LogManager.isVerboseLoggingEnabled()) {
LogManager.d(TAG, "Cannot parse identifier "+i+" because PDU is too short. endIndex: " + endIndex + " PDU endIndex: " + pduToParse.getEndIndex());
}
}
}
else {
Identifier identifier = Identifier.fromBytes(bytesToProcess, mIdentifierStartOffsets.get(i) + startByte, endIndex+1, mIdentifierLittleEndianFlags.get(i));
identifiers.add(identifier);
}
}
for (int i = 0; i < mDataEndOffsets.size(); i++) {
int endIndex = mDataEndOffsets.get(i) + startByte;
if (endIndex > pduToParse.getEndIndex()) {
parseFailed = true;
if (LogManager.isVerboseLoggingEnabled()) {
LogManager.d(TAG, "Cannot parse data field "+i+" because PDU is too short. endIndex: " + endIndex + " PDU endIndex: " + pduToParse.getEndIndex());
else {
Identifier identifier = Identifier.fromBytes(bytesToProcess, mIdentifierStartOffsets.get(i) + startByte, endIndex+1, mIdentifierLittleEndianFlags.get(i));
identifiers.add(identifier);
}
}
else {
String dataString = byteArrayToFormattedString(bytesToProcess, mDataStartOffsets.get(i) + startByte, endIndex, mDataLittleEndianFlags.get(i));
dataFields.add(Long.parseLong(dataString));
}
}

if (mPowerStartOffset != null) {
int endIndex = mPowerEndOffset + startByte;
int txPower = 0;
try {
for (int i = 0; i < mDataEndOffsets.size(); i++) {
int endIndex = mDataEndOffsets.get(i) + startByte;
if (endIndex > pduToParse.getEndIndex()) {
parseFailed = true;
if (LogManager.isVerboseLoggingEnabled()) {
LogManager.d(TAG, "Cannot parse power field because PDU is too short. endIndex: " + endIndex + " PDU endIndex: " + pduToParse.getEndIndex());
LogManager.d(TAG, "Cannot parse data field "+i+" because PDU is too short. endIndex: " + endIndex + " PDU endIndex: " + pduToParse.getEndIndex()+". Setting value to 0");
}
dataFields.add(new Long(0l));
}
else {
String powerString = byteArrayToFormattedString(bytesToProcess, mPowerStartOffset + startByte, mPowerEndOffset + startByte, false);
txPower = Integer.parseInt(powerString)+mDBmCorrection;
// make sure it is a signed integer
if (txPower > 127) {
txPower -= 256;
}
beacon.mTxPower = txPower;
String dataString = byteArrayToFormattedString(bytesToProcess, mDataStartOffsets.get(i) + startByte, endIndex, mDataLittleEndianFlags.get(i));
dataFields.add(Long.parseLong(dataString));
}
}
catch (NumberFormatException e1) {
// keep default value
}
catch (NullPointerException e2) {
// keep default value

if (mPowerStartOffset != null) {
int endIndex = mPowerEndOffset + startByte;
int txPower = 0;
try {
if (endIndex > pduToParse.getEndIndex()) {
parseFailed = true;
if (LogManager.isVerboseLoggingEnabled()) {
LogManager.d(TAG, "Cannot parse power field because PDU is too short. endIndex: " + endIndex + " PDU endIndex: " + pduToParse.getEndIndex());
}
}
else {
String powerString = byteArrayToFormattedString(bytesToProcess, mPowerStartOffset + startByte, mPowerEndOffset + startByte, false);
txPower = Integer.parseInt(powerString)+mDBmCorrection;
// make sure it is a signed integer
if (txPower > 127) {
txPower -= 256;
}
beacon.mTxPower = txPower;
}
}
catch (NumberFormatException e1) {
// keep default value
}
catch (NullPointerException e2) {
// keep default value
}
}
}
}


if (parseFailed) {
beacon = null;
}
Expand Down
31 changes: 30 additions & 1 deletion src/test/java/org/altbeacon/beacon/AltBeaconParserTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,10 @@

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;

import org.altbeacon.beacon.logging.LogManager;
import org.altbeacon.beacon.logging.Loggers;
import org.robolectric.RobolectricTestRunner;

import org.junit.runner.RunWith;
Expand Down Expand Up @@ -31,7 +34,6 @@ public static byte[] hexStringToByteArray(String s) {
}
return data;
}

@Test
public void testRecognizeBeacon() {
BeaconManager.setDebug(true);
Expand Down Expand Up @@ -59,4 +61,31 @@ public void testDetectsAlternateBeconType() {
Beacon beacon = parser.fromScanData(bytes, -55, null);
assertNotNull("Beacon should be not null if parsed successfully", beacon);
}
@Test
public void testParseWrongFormatReturnsNothing() {
BeaconManager.setDebug(true);
org.robolectric.shadows.ShadowLog.stream = System.err;
LogManager.d("XXX", "testParseWrongFormatReturnsNothing start");
byte[] bytes = hexStringToByteArray("02011a1aff1801ffff2f234454cf6d4a0fadf2f4911ba9ffa600010002c509");
AltBeaconParser parser = new AltBeaconParser();
Beacon beacon = parser.fromScanData(bytes, -55, null);
LogManager.d("XXX", "testParseWrongFormatReturnsNothing end");
assertNull("Beacon should be null if not parsed successfully", beacon);
}

@Test
public void testParsesBeaconMissingDataField() {
BeaconManager.setDebug(true);
org.robolectric.shadows.ShadowLog.stream = System.err;
byte[] bytes = hexStringToByteArray("02011a1aff1801beac2f234454cf6d4a0fadf2f4911ba9ffa600010002c5");
AltBeaconParser parser = new AltBeaconParser();
Beacon beacon = parser.fromScanData(bytes, -55, null);
assertEquals("mRssi should be as passed in", -55, beacon.getRssi());
assertEquals("uuid should be parsed", "2f234454-cf6d-4a0f-adf2-f4911ba9ffa6", beacon.getIdentifier(0).toString());
assertEquals("id2 should be parsed", "1", beacon.getIdentifier(1).toString());
assertEquals("id3 should be parsed", "2", beacon.getIdentifier(2).toString());
assertEquals("txPower should be parsed", -59, beacon.getTxPower());
assertEquals("manufacturer should be parsed", 0x118 ,beacon.getManufacturer());
assertEquals("missing data field zero should be zero", new Long(0l), beacon.getDataFields().get(0));
}
}
19 changes: 19 additions & 0 deletions src/test/java/org/altbeacon/beacon/BeaconParserTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -98,6 +98,25 @@ public void testRecognizeBeacon() {
assertEquals("manufacturer should be parsed", 0x118 ,beacon.getManufacturer());
}

@Test
public void testParsesBeaconMissingDataField() {
LogManager.setLogger(Loggers.verboseLogger());
org.robolectric.shadows.ShadowLog.stream = System.err;
byte[] bytes = hexStringToByteArray("02011a1aff1801beac2f234454cf6d4a0fadf2f4911ba9ffa600010002c5");
BeaconParser parser = new BeaconParser();
parser.setBeaconLayout("m:2-3=beac,i:4-19,i:20-21,i:22-23,p:24-24,d:25-25");
Beacon beacon = parser.fromScanData(bytes, -55, null);
assertEquals("mRssi should be as passed in", -55, beacon.getRssi());
assertEquals("uuid should be parsed", "2f234454-cf6d-4a0f-adf2-f4911ba9ffa6", beacon.getIdentifier(0).toString());
assertEquals("id2 should be parsed", "1", beacon.getIdentifier(1).toString());
assertEquals("id3 should be parsed", "2", beacon.getIdentifier(2).toString());
assertEquals("txPower should be parsed", -59, beacon.getTxPower());
assertEquals("manufacturer should be parsed", 0x118 ,beacon.getManufacturer());
assertEquals("missing data field zero should be zero", new Long(0l), beacon.getDataFields().get(0));

}


@Test
public void testRecognizeBeaconWithFormatSpecifyingManufacturer() {
LogManager.setLogger(Loggers.verboseLogger());
Expand Down

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