Found the bug, it was just a SQL syntax error.

api/net/sf/briar/api/protocol/GroupFactory.java

@@ -2,5 +2,5 @@ package net.sf.briar.api.protocol;
 
 public interface GroupFactory {
 
-	Group createGroup(GroupId id, String name, byte[] salt, byte[] publicKey);
+	Group createGroup(GroupId id, String name, boolean restricted, byte[] b);
 }

components/net/sf/briar/db/JdbcDatabase.java

@@ -2,7 +2,6 @@ package net.sf.briar.db;
 
 import java.io.ByteArrayInputStream;
 import java.io.File;
-import java.security.PublicKey;
 import java.sql.Blob;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
@@ -40,9 +39,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private static final String CREATE_LOCAL_SUBSCRIPTIONS =
 		"CREATE TABLE localSubscriptions"
 		+ " (groupId HASH NOT NULL,"
-		+ " name VARCHAR NOT NULL,"
+		+ " groupName VARCHAR NOT NULL,"
-		+ " salt BINARY,"
+		+ " restricted BOOLEAN NOT NULL,"
-		+ " publicKey BINARY,"
+		+ " groupKey BINARY NOT NULL,"
 		+ " PRIMARY KEY (groupId))";
 
 	private static final String CREATE_MESSAGES =
@@ -90,9 +89,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 		"CREATE TABLE contactSubscriptions"
 		+ " (contactId INT NOT NULL,"
 		+ " groupId HASH NOT NULL,"
-		+ " name VARCHAR NOT NULL,"
+		+ " groupName VARCHAR NOT NULL,"
-		+ " salt BINARY,"
+		+ " restricted BOOLEAN NOT NULL,"
-		+ " publicKey BINARY,"
+		+ " groupKey BINARY NOT NULL,"
 		+ " PRIMARY KEY (contactId, groupId),"
 		+ " FOREIGN KEY (contactId) REFERENCES contacts (contactId)"
 		+ " ON DELETE CASCADE)";
@@ -531,14 +530,14 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			String sql = "INSERT INTO localSubscriptions"
-				+ " (groupId, name, salt, publicKey)"
+				+ " (groupId, groupName, restricted, groupKey)"
 				+ " VALUES (?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, g.getId().getBytes());
 			ps.setString(2, g.getName());
-			ps.setBytes(3, g.getSalt());
+			ps.setBoolean(3, g.isRestricted());
-			PublicKey k = g.getPublicKey();
+			if(g.isRestricted()) ps.setBytes(4, g.getPublicKey().getEncoded());
-			ps.setBytes(4, k == null ? null : k.getEncoded());
+			else ps.setBytes(4, g.getSalt());
 			int rowsAffected = ps.executeUpdate();
 			assert rowsAffected == 1;
 			ps.close();
@@ -990,7 +989,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT (groupId, name, salt, publicKey)"
+			String sql = "SELECT groupId, groupName, restricted, groupKey"
 				+ " FROM localSubscriptions";
 			ps = txn.prepareStatement(sql);
 			rs = ps.executeQuery();
@@ -998,9 +997,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 			while(rs.next()) {
 				GroupId id = new GroupId(rs.getBytes(1));
 				String name = rs.getString(2);
-				byte[] salt = rs.getBytes(3);
+				boolean restricted = rs.getBoolean(3);
-				byte[] publicKey = rs.getBytes(4);
+				byte[] key = rs.getBytes(4);
-				subs.add(groupFactory.createGroup(id, name, salt, publicKey));
+				subs.add(groupFactory.createGroup(id, name, restricted, key));
 			}
 			rs.close();
 			ps.close();
@@ -1018,7 +1017,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT (groupId, name, salt, publicKey)"
+			String sql = "SELECT groupId, groupName, restricted, groupKey"
 				+ " FROM contactSubscriptions"
 				+ " WHERE contactId = ?";
 			ps = txn.prepareStatement(sql);
@@ -1028,9 +1027,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 			while(rs.next()) {
 				GroupId id = new GroupId(rs.getBytes(1));
 				String name = rs.getString(2);
-				byte[] salt = rs.getBytes(3);
+				boolean restricted = rs.getBoolean(3);
-				byte[] publicKey = rs.getBytes(4);
+				byte[] key = rs.getBytes(4);
-				subs.add(groupFactory.createGroup(id, name, salt, publicKey));
+				subs.add(groupFactory.createGroup(id, name, restricted, key));
 			}
 			rs.close();
 			ps.close();
@@ -1390,16 +1389,17 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.close();
 			// Store the new subscriptions
 			sql = "INSERT INTO contactSubscriptions"
-				+ "(contactId, groupId, name, salt, publicKey)"
+				+ "(contactId, groupId, groupName, restricted, groupKey)"
 				+ " VALUES (?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			for(Group g : subs) {
 				ps.setBytes(2, g.getId().getBytes());
 				ps.setString(3, g.getName());
-				ps.setBytes(4, g.getSalt());
+				ps.setBoolean(4, g.isRestricted());
-				PublicKey k = g.getPublicKey();
+				if(g.isRestricted())
-				ps.setBytes(5, k == null ? null : k.getEncoded());
+					ps.setBytes(5, g.getPublicKey().getEncoded());
+				else ps.setBytes(5, g.getSalt());
 				ps.addBatch();
 			}
 			int[] rowsAffectedArray = ps.executeBatch();

components/net/sf/briar/protocol/GroupFactoryImpl.java

@@ -19,20 +19,15 @@ class GroupFactoryImpl implements GroupFactory {
 		this.keyParser = keyParser;
 	}
 
-	public Group createGroup(GroupId id, String name, byte[] salt,
+	public Group createGroup(GroupId id, String name, boolean restricted,
-			byte[] publicKey) {
+			byte[] b) {
-		if(salt == null && publicKey == null)
+		if(restricted) {
-			throw new IllegalArgumentException();
-		if(salt != null && publicKey != null)
-			throw new IllegalArgumentException();
-		PublicKey key = null;
-		if(publicKey != null) {
 			try {
-				key = keyParser.parsePublicKey(publicKey);
+				PublicKey key = keyParser.parsePublicKey(b);
+				return new GroupImpl(id, name, null, key);
 			} catch (InvalidKeySpecException e) {
 				throw new IllegalArgumentException(e);
 			}
-		}
+		} else return new GroupImpl(id, name, b, null);
-		return new GroupImpl(id, name, salt, key);
 	}
 }

components/net/sf/briar/protocol/GroupImpl.java

@@ -39,4 +39,14 @@ public class GroupImpl implements Group {
 	public PublicKey getPublicKey() {
 		return publicKey;
 	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof Group && id.equals(((Group) o).getId());
+	}
+
+	@Override
+	public int hashCode() {
+		return id.hashCode();
+	}
 }

components/net/sf/briar/protocol/MessageImpl.java

@@ -54,7 +54,7 @@ class MessageImpl implements Message {
 
 	@Override
 	public boolean equals(Object o) {
-		return o instanceof Message && id.equals(((Message)o).getId());
+		return o instanceof Message && id.equals(((Message) o).getId());
 	}
 
 	@Override

test/build.xml

@@ -13,6 +13,7 @@
 				<path refid='test-classes'/>
 				<path refid='util-classes'/>
 			</classpath>
+			<test name='net.sf.briar.db.BasicH2Test'/>
 			<test name='net.sf.briar.db.DatabaseCleanerImplTest'/>
 			<test name='net.sf.briar.db.H2DatabaseTest'/>
 			<test name='net.sf.briar.db.ReadWriteLockDatabaseComponentTest'/>

test/net/sf/briar/db/BasicH2Test.java

@@ -0,0 +1,117 @@
+package net.sf.briar.db;
+
+import java.io.File;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Random;
+
+import junit.framework.TestCase;
+import net.sf.briar.TestUtils;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class BasicH2Test extends TestCase {
+
+	private static final String CREATE_TABLE =
+		"CREATE TABLE foo"
+		+ " (uniqueId BINARY(32) NOT NULL,"
+		+ " name VARCHAR NOT NULL,"
+		+ " PRIMARY KEY (uniqueId))";
+
+	private final File testDir = TestUtils.getTestDirectory();
+	private final File db = new File(testDir, "db");
+	private final String url = "jdbc:h2:" + db.getPath();
+
+	private Connection connection = null;
+
+	@Before
+	public void setUp() throws Exception {
+		testDir.mkdirs();
+		Class.forName("org.h2.Driver");
+		connection = DriverManager.getConnection(url);
+	}
+
+	@Test
+	public void testCreateTableAndAddRow() throws Exception {
+		// Create the table
+		createTable(connection);
+		// Generate a unique ID
+		byte[] uniqueId = new byte[32];
+		new Random().nextBytes(uniqueId);
+		// Insert the unique ID and name into the table
+		addRow(uniqueId, "foo");
+	}
+
+	@Test
+	public void testCreateTableAddAndRetrieveRow() throws Exception {
+		// Create the table
+		createTable(connection);
+		// Generate a unique ID
+		byte[] uniqueId = new byte[32];
+		new Random().nextBytes(uniqueId);
+		// Insert the unique ID and name into the table
+		addRow(uniqueId, "foo");
+		// Check that the name can be retrieved using the unique ID
+		assertEquals("foo", getName(uniqueId));
+	}
+	
+	private void addRow(byte[] uniqueId, String name) throws SQLException {
+		String sql = "INSERT INTO foo (uniqueId, name) VALUES (?, ?)";
+		PreparedStatement ps = null;
+		try {
+			ps = connection.prepareStatement(sql);
+			ps.setBytes(1, uniqueId);
+			ps.setString(2, name);
+			int rowsAffected = ps.executeUpdate();
+			ps.close();
+			assertEquals(1, rowsAffected);
+		} catch(SQLException e) {
+			connection.close();
+			throw e;
+		}
+	}
+
+	private String getName(byte[] uniqueId) throws SQLException {
+		String sql = "SELECT name FROM foo WHERE uniqueID = ?";
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			ps = connection.prepareStatement(sql);
+			ps.setBytes(1, uniqueId);
+			rs = ps.executeQuery();
+			assertTrue(rs.next());
+			String name = rs.getString(1);
+			assertFalse(rs.next());
+			rs.close();
+			ps.close();
+			return name;
+		} catch(SQLException e) {
+			connection.close();
+			throw e;
+		}
+	}
+
+	private void createTable(Connection connection) throws SQLException {
+		Statement s;
+		try {
+			s = connection.createStatement();
+			s.executeUpdate(CREATE_TABLE);
+			s.close();
+		} catch(SQLException e) {
+			connection.close();
+			throw e;
+		}
+	}
+
+	@After
+	public void tearDown() throws Exception {
+		if(connection != null) connection.close();
+		TestUtils.deleteTestDirectory(testDir);
+	}
+}

test/net/sf/briar/db/DatabaseComponentTest.java

@@ -468,6 +468,7 @@ public abstract class DatabaseComponentTest extends TestCase {
 			will(returnValue(true));
 			oneOf(ackWriter).addBatchId(batchId1);
 			will(returnValue(false));
+			oneOf(ackWriter).finish();
 			// Record the batch that was acked
 			oneOf(database).removeBatchesToAck(txn, contactId, acks);
 		}});

test/net/sf/briar/db/H2DatabaseTest.java

@@ -76,8 +76,8 @@ public class H2DatabaseTest extends TestCase {
 		random.nextBytes(raw);
 		message = new TestMessage(messageId, MessageId.NONE, groupId, authorId,
 				timestamp, raw);
-		group = groupFactory.createGroup(groupId, "Group name",
+		group = groupFactory.createGroup(groupId, "Group name", false,
-				TestUtils.getRandomId(), null);
+				TestUtils.getRandomId());
 	}
 
 	@Before
@@ -533,7 +533,7 @@ public class H2DatabaseTest extends TestCase {
 		MessageId childId3 = new MessageId(TestUtils.getRandomId());
 		GroupId groupId1 = new GroupId(TestUtils.getRandomId());
 		Group group1 = groupFactory.createGroup(groupId1, "Another group name",
-				TestUtils.getRandomId(), null);
+				false, TestUtils.getRandomId());
 		Message child1 = new TestMessage(childId1, messageId, groupId,
 				authorId, timestamp, raw);
 		Message child2 = new TestMessage(childId2, messageId, groupId,
@@ -758,7 +758,7 @@ public class H2DatabaseTest extends TestCase {
 	public void testUpdateSubscriptions() throws DbException {
 		GroupId groupId1 = new GroupId(TestUtils.getRandomId());
 		Group group1 = groupFactory.createGroup(groupId1, "Another group name",
-				TestUtils.getRandomId(), null);
+				false, TestUtils.getRandomId());
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
 
@@ -783,7 +783,7 @@ public class H2DatabaseTest extends TestCase {
 	throws DbException {
 		GroupId groupId1 = new GroupId(TestUtils.getRandomId());
 		Group group1 = groupFactory.createGroup(groupId1, "Another group name",
-				TestUtils.getRandomId(), null);
+				false, TestUtils.getRandomId());
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();