问题
I have a Java application where I use Akka Typed Actors. The code has no errors in Eclipse, but when I start my application it crashes and prints this error:
Exception in thread "main" java.lang.VerifyError: Inconsistent stackmap frames at branch target 266 in method com.example.actors.DBActor.getItems(Lorg/joda/time/DateTime;Lorg/joda/time/DateTime;)I at offset 170
at com.example.ui.Main$1.create(Main.java:31)
at akka.actor.TypedActor$$anonfun$newInstance$3.apply(TypedActor.scala:677)
at akka.actor.TypedActor$$anonfun$newInstance$3.apply(TypedActor.scala:677)
at akka.actor.TypedActor$.newTypedActor(TypedActor.scala:847)
at akka.actor.TypedActor$$anonfun$newInstance$1.apply(TypedActor.scala:601)
at akka.actor.TypedActor$$anonfun$newInstance$1.apply(TypedActor.scala:601)
at akka.actor.LocalActorRef.akka$actor$LocalActorRef$$newActor(ActorRef.scala:1084)
at akka.actor.LocalActorRef$$anonfun$2.apply(ActorRef.scala:628)
at akka.actor.LocalActorRef$$anonfun$2.apply(ActorRef.scala:628)
at akka.util.ReentrantGuard.withGuard(LockUtil.scala:20)
at akka.actor.LocalActorRef.<init>(ActorRef.scala:628)
at akka.actor.Actor$.actorOf(Actor.scala:249)
at akka.actor.TypedActor$.newInstance(TypedActor.scala:677)
at akka.actor.TypedActor.newInstance(TypedActor.scala)
at com.example.ui.Main.main(Main.java:29)
I don't understand what can be wrong. I have check my com.example.actors.DBActor.getItems()
but there is no error in it. What could be wrong?
UPDATE
Below is example on code where I get this error. I have these jar-files on the "Build path" in Eclipse:
derby.jar
(from JDK7) (only an in-memory database is used in this example)akka-actor-1.2.jar
akka-typed-actor-1.2.jar
aspectwerkz-2.2.3.jar
scala-library.jar
Here is the code:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import akka.actor.TypedActor;
import akka.actor.TypedActorFactory;
public class App {
public App() {
TypedActor.newInstance(Backend.class, new TypedActorFactory() {
public TypedActor create() {
return new DataActor();
}
});
}
class DataActor extends TypedActor implements Backend {
@Override
public void insertData(String msg) {
final String sqlSelect = "SELECT msg FROM SESSION.messages "+
"WHERE to_user_id = ? AND from_user_id = ?";
final String connectionURL = "jdbc:derby:memory:memdatabase;create=true";
/* if this declaration is moved to where the string is used
in the conditional, the conditional can be used */
String result;
try(Connection conn = DriverManager.getConnection(connectionURL);) {
try(PreparedStatement ps = conn.prepareStatement(sqlSelect);
ResultSet rs = new QueryHelper(ps)
.integer(13).integer(26).executeQuery();) {
/* this doesn't work */
result = (rs.next()) ? rs.getString("text")
: null;
/* but this work:
String result = (rs.next()) ? rs.getString("text")
: null;
*/
/* this works fine
while(rs.next()) {
result = rs.getString("msg");
} */
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
class QueryHelper {
private final PreparedStatement ps;
private int index = 1;
public QueryHelper(PreparedStatement ps) {
this.ps = ps;
}
public QueryHelper integer(int param) throws SQLException {
ps.setInt(index++, param);
return this;
}
public ResultSet executeQuery() throws SQLException {
return ps.executeQuery();
}
}
public interface Backend {
public void insertData(String text);
}
public static void main(String[] args) {
new App();
}
}
回答1:
I have found out that this bug is in places where I use multiple resources in a single Java 7 try-with-resources statement.
E.g. this code will have the bug:
try (Connection conn = DriverManager.getConnection(connURL);
PreparedStatement ps = conn.prepareStatement(sql);) {
// do something
} catch (SQLException e) {
e.printStackTrace();
}
and a workaround would look like:
try (Connection conn = DriverManager.getConnection(connURL);) {
try (PreparedStatement ps = conn.prepareStatement(sql);) {
// do something
}
} catch (SQLException e) {
e.printStackTrace();
}
回答2:
run java with the option -XX:-UseSplitVerifier
来源:https://stackoverflow.com/questions/8079504/akka-actors-fails-verifyerror-inconsistent-stackmap-frames-at-branch-target