Handling Java UDx Dependencies

If your Java UDx relies on one or more external libraries, you can handle the dependencies in one of three ways:

Important: In previous versions of Vertica, the JavaClassPathForUDx configuration parameter set the locations of external libraries for all Java UDxs. In Vertica Version 7.1, this configuration parameter is deprecated. It will be removed in a future version. If you upgrade from a previous version of Vertica, switch any existing Java UDxs that rely on support libraries to use the new DEPENDS keyword. To make this switch, use the ALTER LIBRARY statement to recreate the UDx library. In this statement, supply the DEPENDS  keyword to specify the directory containing the support libraries.

External Library Example

The following example demonstrates using an external library with a Java UDx.

The following sample code defines a simple class, named VowelRemover. It contains a single method, named removevowels, that removes all of the vowels (the letters a, e, i, o u, and y) from a string.

package com.mycompany.libs;

public class VowelRemover {
	public String removevowels(String input) {
		return input.replaceAll("(?i)[aeiouy]", "");

You can compile this class and package it into a JAR file with the following commands:

$ javac -g com/mycompany/libs/VowelRemover.java
$ jar cf mycompanylibs.jar com/mycompany/libs/VowelRemover.class

The following code defines a Java UDSF, named DeleteVowels, that uses the library defined in the preceding example code. DeleteVowels accepts a single VARCHAR as input, and returns a VARCHAR.

package com.mycompany.udx;
// Import the support class created earlier
import com.mycompany.libs.VowelRemover;
// Import the Vertica SDK
import com.vertica.sdk.*;

public class DeleteVowelsFactory extends ScalarFunctionFactory {

    public ScalarFunction createScalarFunction(ServerInterface arg0) {
        return new DeleteVowels();

    public void getPrototype(ServerInterface arg0, ColumnTypes argTypes,
            ColumnTypes returnTypes) {
        // Accept a single string and return a single string.
    public void getReturnType(ServerInterface srvInterface,
            SizedColumnTypes argTypes,
            SizedColumnTypes returnType){
        // Output will be no larger than the input.
        argTypes.getColumnType(0).getStringLength(), "RemovedVowels");
    public class DeleteVowels extends ScalarFunction
        public void processBlock(ServerInterface arg0, BlockReader argReader,
                BlockWriter resWriter) throws UdfException, DestroyInvocation {
            // Create an instance of the  VowelRemover object defined in 
            // the library.
            VowelRemover remover = new VowelRemover();
            do {
                String instr = argReader.getString(0);
                // Call the removevowels method defined in the library.
            } while (argReader.next());


Use the following commands to build the example UDSF and package it into a JAR:

$ javac -g -cp /opt/vertica/bin/VerticaSDK.jar\
   /opt/vertica/sdk/com/vertica/sdk/BuildInfo.java -d .
$ javac -g -cp mycompanylibs.jar:/opt/vertica/bin/VerticaSDK.jar\
$ jar cf DeleteVowelsLib.jar com/mycompany/udx/*.class \

To install the UDx library, you must copy both of the JAR files to a node in the Vertica cluster. Then, connect to the node to execute the CREATE LIBRARY statement.

The following example demonstrates how to load the UDx library after you copy the JAR files to the home directory of the user. The DEPENDS keyword tells Vertica that the UDx library depends on the mycompanylibs.jar file.

=> CREATE LIBRARY DeleteVowelsLib AS 
   '/home/dbadmin/DeleteVowelsLib.jar' DEPENDS '/home/dbadmin/mycompanylibs.jar' 
=> CREATE FUNCTION deleteVowels AS language 'java' NAME 
  'com.mycompany.udx.DeleteVowelsFactory' LIBRARY DeleteVowelsLib;
=> SELECT deleteVowels('I hate vowels!');
  ht vwls!
(1 row)