The server's DateStyle parameter was changed to ISO. The JDBC driver requires DateStyle to begin with ISO for correct operation

[afarber]

Hello and thank you for developing this software.

There seems to be a bug in the version 42.2.0.jre7 though:

I use Jetty 9.4.7 on CentOS 7.4 with PostgreSQL 9.6.6 with pgbouncer and postgresql-jdbc-4.2.0:

# rpm -qa | grep postgr
postgresql96-server-9.6.6-1PGDG.rhel7.x86_64
postgresql-jdbc-javadoc-42.2.0-1.rhel7.noarch
postgresql96-libs-9.6.6-1PGDG.rhel7.x86_64
postgresql96-devel-9.6.6-1PGDG.rhel7.x86_64
postgresql-libs-9.2.23-3.el7_4.x86_64
postgresql-jdbc-42.2.0-1.rhel7.noarch
postgresql96-9.6.6-1PGDG.rhel7.x86_64

I run a WAR file in Jetty, compiled as following:

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <jetty.version>9.4.7.v20170914</jetty.version>
        <pgsql.version>42.1.4.jre7</pgsql.version>
    </properties>

When I change the last line to <pgsql.version>42.2.0.jre7</pgsql.version> and recompile my WAR-file, then the Java code -

String SQL_MERGE_USERS = "SELECT words_merge_users(?::jsonb, ?::inet, ?::text, ?::text, ?::text)";

// the next line in MyListener.java throws the exception

try (Connection db = DriverManager.getConnection(DATABASE_URL, DATABASE_USER, DATABASE_PASS);
        PreparedStatement st = db.prepareStatement(SQL_MERGE_USERS)) {
    st.setString(1, users);
    st.setString(2, ip);
    st.setString(3, fcm);
    st.setString(4, apns);
    st.setString(5, adm);
    ResultSet rs = st.executeQuery();

throws an exception:

WARNING: SQLException occurred while connecting to 127.0.0.1:6432
org.postgresql.util.PSQLException: The server's DateStyle parameter was changed to ISO. The JDBC driver requires DateStyle to begin with ISO for correct operation.
at org.postgresql.core.v3.QueryExecutorImpl.receiveParameterStatus(QueryExecutorImpl.java:2603)
at org.postgresql.core.v3.QueryExecutorImpl.readStartupMessages(QueryExecutorImpl.java:2569)
at org.postgresql.core.v3.QueryExecutorImpl.<init>(QueryExecutorImpl.java:131)
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:212)
at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195)
at org.postgresql.Driver.makeConnection(Driver.java:452)
at org.postgresql.Driver.connect(Driver.java:254)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at de.slova.websockets.MyListener.mergeUsers(MyListener.java:152)
at de.slova.websockets.MyListener.handleLogin(MyListener.java:208)
at de.slova.websockets.MyListener.onWebSocketText(MyListener.java:83)
at org.eclipse.jetty.websocket.common.events.JettyListenerEventDriver.onTextMessage(JettyListenerEventDriver.java:189)
at org.eclipse.jetty.websocket.common.message.SimpleTextMessage.messageComplete(SimpleTextMessage.java:69)
at org.eclipse.jetty.websocket.common.events.AbstractEventDriver.appendMessage(AbstractEventDriver.java:66)
at org.eclipse.jetty.websocket.common.events.JettyListenerEventDriver.onTextFrame(JettyListenerEventDriver.java:158)
at org.eclipse.jetty.websocket.common.events.AbstractEventDriver.incomingFrame(AbstractEventDriver.java:162)
at org.eclipse.jetty.websocket.common.WebSocketSession.incomingFrame(WebSocketSession.java:375)
at org.eclipse.jetty.websocket.common.extensions.AbstractExtension.nextIncomingFrame(AbstractExtension.java:182)
at org.eclipse.jetty.websocket.common.extensions.compress.PerMessageDeflateExtension.nextIncomingFrame(PerMessageDeflateExtension.java:105)
at org.eclipse.jetty.websocket.common.extensions.compress.CompressExtension.forwardIncoming(CompressExtension.java:142)
at org.eclipse.jetty.websocket.common.extensions.compress.PerMessageDeflateExtension.incomingFrame(PerMessageDeflateExtension.java:85)
at org.eclipse.jetty.websocket.common.extensions.ExtensionStack.incomingFrame(ExtensionStack.java:220)
at org.eclipse.jetty.websocket.common.Parser.notifyFrame(Parser.java:220)
at org.eclipse.jetty.websocket.common.Parser.parse(Parser.java:256)
at org.eclipse.jetty.websocket.common.io.AbstractWebSocketConnection.readParse(AbstractWebSocketConnection.java:679)
at org.eclipse.jetty.websocket.common.io.AbstractWebSocketConnection.onFillable(AbstractWebSocketConnection.java:511)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:279)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:110)
at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:124)
at org.eclipse.jetty.util.thread.Invocable.invokePreferred(Invocable.java:128)
at org.eclipse.jetty.util.thread.Invocable$InvocableExecutor.invoke(Invocable.java:222)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:294)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:199)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:673)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:591)
at java.lang.Thread.run(Thread.java:745)

However I do have datestyle setting in my postgresql.conf:

datestyle = 'iso, mdy'

and I can see it at the console:

# psql
psql (9.6.6)
Type "help" for help.

words=> show datestyle;
 DateStyle 
-----------
 ISO, MDY
(1 row)

I.e. my datestyle setting (unchanged from stock installation) does begin with "ISO" as the exception wants it too.