Java error when combining Lambdas and multiple catch clauses?
•
Java
import java.io.*;
import java.io.*;
import java.net.*;
public class Test {
public static void main(String[] arguments) throws Exception {
Runnable runnable = () -> {
try {
throwException();
}
catch (SocketException|EOFException exception) {
System.err.println("wrong");
}
catch (IOException exception) {
System.err.println("right");
}
};
runnable.run();
}
private static void throwException() throws IOException {
throw new NotSerializableException();
}
}
Why does this program print "wrong"? If I delete a lambda, or if I separate multiple catch clauses, it prints "yes"
$javac -version javac 1.8.0_11 $java -version java version "1.8.0_11" Java(TM) SE Runtime Environment (build 1.8.0_11-b12) Java HotSpot(TM) 64-Bit Server VM (build 25.11-b03,mixed mode)
Solution
This is 1.8 0_ 20 Fixed bug, from 1.8 0_ 11:
The actual error report is jdk-8036942
The actual error is the loss of type information in the compiler:
I saw it on 8u20 (I forgot to give a command line parameter, and no 8u20 will execute correctly):
wlan1-loopback% /usr/lib/jvm/java-8-oracle/bin/javap -c Test
Compiled from "Test.java"
public class Test {
public test();
Code:
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
public static void main(java.lang.String[]) throws java.lang.Exception;
Code:
0: invokedynamic #2,0 // InvokeDynamic #0:run:()Ljava/lang/Runnable;
5: astore_1
6: aload_1
7: invokeinterface #3,1 // InterfaceMethod java/lang/Runnable.run:()V
12: return
}
wlan1-loopback% java Test
right
wlan1-loopback% java -version
java version "1.8.0_20"
Java(TM) SE Runtime Environment (build 1.8.0_20-b26)
Java HotSpot(TM) 64-Bit Server VM (build 25.20-b23,mixed mode)
wlan1-loopback%
correct:
public class Test {
public test();
descriptor: ()V
Code:
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
public static void main(java.lang.String[]) throws java.lang.Exception;
descriptor: ([Ljava/lang/String;)V
Code:
0: invokedynamic #2,1 // InterfaceMethod java/lang/Runnable.run:()V
12: return
private static void throwException() throws java.io.IOException;
descriptor: ()V
Code:
0: new #4 // class java/io/NotSerializableException
3: dup
4: invokespecial #5 // Method java/io/NotSerializableException."<init>":()V
7: athrow
private static void lambda$main$0();
descriptor: ()V
Code:
0: invokestatic #6 // Method throwException:()V
3: goto 27
6: astore_0
7: getstatic #9 // Field java/lang/System.err:Ljava/io/PrintStream;
10: ldc #10 // String wrong
12: invokevirtual #11 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
15: goto 27
18: astore_0
19: getstatic #9 // Field java/lang/System.err:Ljava/io/PrintStream;
22: ldc #13 // String right
24: invokevirtual #11 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
27: return
Exception table:
from to target type
0 3 6 Class java/net/SocketException
0 3 6 Class java/io/EOFException
0 3 18 Class java/io/IOException
}
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