Scripting Scala – JSR-223

With the release of Scala 2.11 it became fully JSR-223 compliant scripting language for Java. JSR-223 is the community request to allow scripting language to have an interface to Java and to allow Java to use the scripting language inside of applications.

In Java 8 the Nashorn scripting engine was released as a native component of the JDK to support JavaScript with applications. This is possible through another JSR in Java 7 – namely JSR-229, which brings support for invoke dynamics, a way to support dynamic programming by the Java byte code compiler. Nashorn can be seen as a proof of concept of this newly added functionality. Continue reading “Scripting Scala – JSR-223” →

JPMML Example Random Forest

The Predictive Model Markup Language (PMML) developed by the Data Mining Group is a standardized XML-based representation of mining models to be used and shared across languages or tools. The standardized definition allows a classification model trained with R to be used with Storm for example. Many projects related to Big Data have some support for PMML, which is often implemented by JPMML. Continue reading “JPMML Example Random Forest” →

Using Self-Signed Certificates with Java and Maven

JAVA applications using JSSE (Java Secure Socket Extension) can’t connect to servers with self-signed or untrusted certificates by default. Maven for example is not able to download required dependencies from a nexus server, if that uses a self-signed certificate or the certificate authority is not recognized. If you try to connect to a server of that kind a security ValidatorException will be thrown:

Error transferring file: sun.security.validator.ValidatorException:
PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException:
unable to find valid certification path to requested target

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