PWC 254

Task 1 Raku done
Task 2 Raku done

Task 1 PL/Perl done
Task 2 PL/Perl done

Task 1 PL/PgSQL done
Task 2 PL/PgSQL done

Task 1 Python done
Task 2 Python done

Task 1  PL/Java done
Task2  PL/java done

1 files changed, 69 insertions, 0 deletions

diff --git a/challenge-254/luca-ferrari/pljava/src/main/java/Task2.java b/challenge-254/luca-ferrari/pljava/src/main/java/Task2.java
new file mode 100644
index 0000000000..034943bebc
--- /dev/null
+++ b/challenge-254/luca-ferrari/pljava/src/main/java/Task2.java
@@ -0,0 +1,69 @@
+package PWC254;
+
+/**
+ * PL/Java implementation for PWC 254
+ * Task 1
+ * See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-254>
+ *
+ *
+ * To compile on the local machine:
+
+ $ export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64/  # if not already set
+ $ mvn clean build
+ $ $ scp target/PWC253-1.jar  luca@venkman:/tmp
+
+
+ * To install into PostgreSQL execute:
+
+ select sqlj.install_jar( 'file:///tmp/PWC254-1.jar', 'PWC254', true );
+ select sqlj.set_classpath( 'public', 'PWC254' );
+
+ select task1_pljava();
+
+ and then to redeploy:
+
+ select sqlj.replace_jar( 'file:///tmp/PWC254-1.jar', 'PWC254', true );
+
+*/
+
+import org.postgresql.pljava.*;
+import org.postgresql.pljava.annotation.Function;
+import static org.postgresql.pljava.annotation.Function.Effects.IMMUTABLE;
+import static org.postgresql.pljava.annotation.Function.OnNullInput.RETURNS_NULL;
+
+import java.util.*;
+import java.sql.SQLException;
+import java.util.logging.*;
+
+public class Task2 {
+    private final static Logger logger = Logger.getAnonymousLogger();
+
+    @Function( onNullInput = RETURNS_NULL, effects = IMMUTABLE )
+    public static final String task2_pljava( String word ) throws SQLException {
+	String result = "";
+	Stack<String> vowels = new Stack<String>();
+
+	for ( String letter : word.split( "" ) ) {
+	    if ( isVowel( letter ) )
+		vowels.push( letter );
+	}
+
+	for ( String letter : word.split( "" ) ) {
+	    if ( ! isVowel( letter ) || vowels.empty() )
+		result += letter;
+	    else
+		result += vowels.pop();
+	}
+
+	return result;
+    }
+
+
+	public static final boolean isVowel( String letter ) {
+	    return letter.toLowerCase().equals( "a" )
+		|| letter.toLowerCase().equals( "e" )
+		|| letter.toLowerCase().equals( "i" )
+		|| letter.toLowerCase().equals( "o" )
+		|| letter.toLowerCase().equals( "u" );
+	}
+}