package io.dropwizard.metrics;
import static org.assertj.core.api.Assertions.assertThat;
import java.lang.management.ManagementFactory;
import java.util.ArrayList;
import java.util.List;
import javax.management.JMException;
import javax.management.MBeanServer;
import javax.management.ObjectInstance;
import javax.management.ObjectName;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
public class JmxAttributeGaugeTest {
private static MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer();
private static List<ObjectName> registeredMBeans = new ArrayList<>();
public interface JmxTestMBean {
Long getValue();
}
private static class JmxTest implements JmxTestMBean {
@Override
public Long getValue() {
return Long.MAX_VALUE;
}
}
@BeforeClass
public static void setUp() throws Exception {
registerMBean(new ObjectName("JmxAttributeGaugeTest:type=test,name=test1"));
registerMBean(new ObjectName("JmxAttributeGaugeTest:type=test,name=test2"));
}
@AfterClass
public static void tearDown() {
for (ObjectName objectName : registeredMBeans) {
try {
mBeanServer.unregisterMBean(objectName);
} catch (Exception e) {
// ignore
}
}
}
@Test
public void returnsJmxAttribute() throws Exception {
ObjectName objectName = new ObjectName("java.lang:type=ClassLoading");
JmxAttributeGauge gauge = new JmxAttributeGauge(mBeanServer, objectName, "LoadedClassCount");
assertThat(gauge.getValue()).isInstanceOf(Integer.class);
assertThat((Integer) gauge.getValue()).isGreaterThan(0);
}
@Test
public void returnsNullIfAttributeDoesNotExist() throws Exception {
ObjectName objectName = new ObjectName("java.lang:type=ClassLoading");
JmxAttributeGauge gauge = new JmxAttributeGauge(mBeanServer, objectName, "DoesNotExist");
assertThat(gauge.getValue()).isNull();
}
@Test
public void returnsNullIfMBeanNotFound() throws Exception {
ObjectName objectName = new ObjectName("foo.bar:type=NoSuchMBean");
JmxAttributeGauge gauge = new JmxAttributeGauge(mBeanServer, objectName, "LoadedClassCount");
assertThat(gauge.getValue()).isNull();
}
@Test
public void returnsAttributeForObjectNamePattern() throws Exception {
ObjectName objectName = new ObjectName("JmxAttributeGaugeTest:name=test1,*");
JmxAttributeGauge gauge = new JmxAttributeGauge(mBeanServer, objectName, "Value");
assertThat(gauge.getValue()).isInstanceOf(Long.class);
assertThat((Long) gauge.getValue()).isEqualTo(Long.MAX_VALUE);
}
@Test
public void returnsNullIfObjectNamePatternAmbiguous() throws Exception {
ObjectName objectName = new ObjectName("JmxAttributeGaugeTest:type=test,*");
JmxAttributeGauge gauge = new JmxAttributeGauge(mBeanServer, objectName, "Value");
assertThat(gauge.getValue()).isNull();
}
private static void registerMBean(ObjectName objectName) throws JMException {
ObjectInstance objectInstance = mBeanServer.registerMBean(new JmxTest(), objectName);
registeredMBeans.add(objectInstance.getObjectName());
}
}