Version Comparator in Java

Version.java

package foo;

import static java.util.regex.Pattern.compile;
import static org.apache.commons.lang3.StringUtils.substringAfter;

import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringUtils;
import org.apache.maven.artifact.versioning.ArtifactVersion;
import org.apache.maven.artifact.versioning.ComparableVersion;
import org.apache.maven.artifact.versioning.DefaultArtifactVersion;

/**
 * <p>Utility to compare version.</p>
 *
 * @author yclian
 * @since 20120507
 * @version 20120507
 */
public final class Version {

    private static final Pattern PATTERN_APPROXIMATION = compile("^([\\d\\.]+\\.)*(\\d+)$");

    private ComparableVersion mVersion;

    private Version(String v) {
        mVersion = new ComparableVersion(v);
    }

    public static Version compare(String v) {
        return new Version(v);
    }

    /**
     * <p>Return the result of {@link Comparable#compareTo(Object)}. Very limited as it doesn't support {@code &gt;=}, {@code &lt;=} and {@code ~&gt;}.</p>
     *
     * @param v
     * @return
     */
    public int with(String v) {
        return mVersion.compareTo(new ComparableVersion(v));
    }

    public boolean eq(String v) { return with(v) == 0; }
    public boolean le(String v) { int c = with(v); return c == 0 || c == -1; }
    public boolean lt(String v) { return with(v) == -1; }
    public boolean ge(String v) { int c = with(v); return c == 0 || c == 1; }
    public boolean gt(String v) { return with(v) == 1; }

    /**
     * <p>Approximately greater than, inspired by (and works exactly like) RubyGems.</p>
     *
     * @see <a href="http://docs.rubygems.org/read/chapter/16">RubyGems Manuals - Specifying Versions</a>
     * @param v
     * @return
     */
    public boolean agt(String v) {
        return ge(v) && lt(approximateUpper(v));
    }

    private String approximateUpper(String v) {
        Matcher m = PATTERN_APPROXIMATION.matcher(v.split("\\.\\d+$")[0]);
        if (m.find()) {
            int i = Integer.parseInt(m.group(2));
            return (null != m.group(1) ? m.group(1) : "") + ++i;
        } else {
            return v;
        }
    }
}

VersionTest.java

package foo;

import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.assertFalse;
import static junit.framework.Assert.assertTrue;
import static foo.Version.compare;

import org.junit.Before;
import org.junit.Test;

/**
 * @author yclian
 * @since 20120507
 * @version 20120507
 */
public class VersionTest {

    @Before
    public void setUp() {}

    @Test
    public void testCompare() {
        assertEquals(-1, compare("1.0.1").with("1.0.2"));
        assertEquals(1, compare("1.0.2.1").with("1.0.2"));
        assertTrue(compare("1.0.2").eq("1.0.2"));
    }

    @Test
    public void testApproximation() {
        assertTrue(compare("1.0.2").agt("1.0")); // ~> 1.0 => >= 1.0 && < 2.0
        assertFalse(compare("2.0").agt("1.0"));
        assertTrue(compare("1.9").agt("1.0")); // ~> 1.0 => >= 1.0 && < 2.0
        assertFalse(compare("0.9").agt("1.0"));
        assertTrue(compare("1.0.2").agt("1.0.2")); // ~> 1.0.2 => >= 1.0.2 && < 1.1
        assertFalse(compare("1.2").agt("1.0.2"));
    }
}

commons-lang3 is unnecessary.

what is the right maven dependency to use for org.apache.maven.artifact.versioning ?

@Sergey80: Try "maven-artifact".

See also: http://stackoverflow.com/a/6640972/36397

For Android (or Java projects) you can use my tiny library which does not use external dependencies: https://github.com/G00fY2/version-compare