Modernizer Maven Plugin detects uses of legacy APIs which modern Java versions supersede. These modern APIs are often more performant, safer, and idiomatic than the legacy equivalents. For example, Modernizer can detect uses of Vector instead of ArrayList, String.getBytes(String) instead of String.getBytes(Charset), and Guava Objects.equal instead of Java 7 Objects.equals. The default configuration detects over 100 legacy APIs, including third-party libraries like Guava.

To run Modernizer, add the following to the <plugins> stanza in your pom.xml then invoke mvn modernizer:modernizer:

<plugin>
  <groupId>org.gaul</groupId>
  <artifactId>modernizer-maven-plugin</artifactId>
  <version>1.3.0</version>
  <configuration>
    <javaVersion>1.8</javaVersion>
  </configuration>
</plugin>

The <configuration> stanza can contain several elements:

• <javaVersion> enables violations based on target Java version, e.g., 1.8. For example, Modernizer will detect uses of Vector as violations when targeting Java 1.2 but not when targeting Java 1.1. Required parameter.
• <failOnViolations> fail phase if Modernizer detects any violations. Defaults to true.
• <includeTestClasses> run Modernizer on test classes. Defaults to true.
• <violationsFile> user-specified violation file. Also disables standard violation checks.
• <exclusionsFile> disables user-specified violations. This is a text file with one exclusion per line in the javap format: java/lang/String.getBytes:(Ljava/lang/String;)[B.
• <ignorePackages> package prefixes to ignore, specified using <ignorePackage> child elements. Specifying foo.bar subsequently ignores foo.bar.*, foo.bar.baz.* and so on.

To run Modernizer during the verify phase of your build, add the following to the modernizer <plugin> stanza in your pom.xml:

<executions>
  <execution>
    <id>modernizer</id>
    <phase>verify</phase>
    <goals>
      <goal>modernizer</goal>
    </goals>
  </execution>
</executions>

ASM provides Java bytecode introspection which enables Modernizer's checks. javac -Xlint:deprecated can detect uses of interfaces with @Deprecated annotations. Overstock.com library-detectors can detect uses of interfaces with @Beta annotations. Checkstyle IllegalInstantiation and Regexp checks can mimic some of Modernizer's functionality.

Copyright (C) 2014-2015 Andrew Gaul

Licensed under the Apache License, Version 2.0