RocksDB 4.5.1 JNI Comparator Example

CompTest.java

package comptest;

import org.rocksdb.*;

import static java.nio.charset.StandardCharsets.UTF_8;

/**
 * Created by aretter on 14/06/2016.
 */
public class CompTest {

    public static void main(final String args[]) throws RocksDBException {
        RocksDB.loadLibrary();

        final ComparatorOptions comparatorOptions = new ComparatorOptions();

        final Comparator myComparator = new Comparator(comparatorOptions) {
            public String name() {
                return "my comparator";
            }

            public int compare(final Slice s1, final Slice s2) {
                return s1.data().length - s2.data().length;
            }
        };

        final byte[] key1 = "key1".getBytes(UTF_8);
        final byte[] value1 = "value1".getBytes(UTF_8);

        RocksDB db = null;
        Options options = null;
        try {
            options = new Options()
                    .setCreateIfMissing(true)
                    .setComparator(myComparator);

            db = RocksDB.open(options, "/tmp/comptest");
            db.put(key1, value1);
            System.out.println(new String(db.get(key1), UTF_8));
        } finally {
            if(options != null) {
                options.dispose();
            }
            if(db != null) {
                db.close();
            }
        }
    }
}

The maven pom.xml looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>rocks-comp-test</groupId>
    <artifactId>rocks-comp-test</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.rocksdb</groupId>
            <artifactId>rocksdbjni</artifactId>
            <version>4.5.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>

        </plugins>
    </build>

</project>