TomcatRule.java

package com.example.testing;

import com.google.common.base.Preconditions;
import com.google.common.io.Files;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.startup.Tomcat;
import org.jboss.shrinkwrap.resolver.api.maven.Maven;
import org.junit.rules.ExternalResource;

import java.io.File;
import java.net.URI;

public class TomcatRule extends ExternalResource
{
    private final String mavenCoordinates;
    private Tomcat tomcat;
    private File tmp;
    private int port;

    public TomcatRule(String mavenCoordinates)
    {
        this.mavenCoordinates = mavenCoordinates;
    }

    @Override
    protected void before() throws Throwable
    {
        tmp = Files.createTempDir();
        Preconditions.checkState(new File(tmp, "webapps").mkdirs(), "unable to create exploded webapp root");
        File war = Maven.resolver()
                        .resolve(mavenCoordinates)
                        .withTransitivity()
                        .asSingleFile();
        port = NetUtil.findUnusedPort();

        tomcat = new Tomcat();
        tomcat.setBaseDir(tmp.getAbsolutePath());
        tomcat.setPort(port);
        tomcat.addWebapp("/", war.getAbsolutePath());
        tomcat.start();
    }

    public URI getBaseUri()
    {
        return URI.create("http://localhost:" + port + "/");
    }

    @Override
    protected void after()
    {
        try {
            tomcat.stop();
        }
        catch (LifecycleException e) {
            throw new IllegalStateException("Unable to stop tomcat", e);
        }
    }
}