Merge PR #394: [WIP] Update jmx-scraper module to follow style guide

Author: trask

jmx-scraper/src/main/java/io/opentelemetry/contrib/jmxscraper/InvalidArgumentException.java

@@ -9,7 +9,7 @@
  * Exception indicating something is wrong with the provided arguments or reading the configuration
  * from them
  */
-public class InvalidArgumentException extends Exception {
+public final class InvalidArgumentException extends Exception {
 
   private static final long serialVersionUID = 0L;
 

jmx-scraper/src/main/java/io/opentelemetry/contrib/jmxscraper/JmxConnectorBuilder.java

@@ -5,6 +5,8 @@
 
 package io.opentelemetry.contrib.jmxscraper;
 
+import static java.util.logging.Level.WARNING;
+
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.net.MalformedURLException;
@@ -17,7 +19,6 @@
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
-import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.management.remote.JMXConnector;
@@ -33,7 +34,7 @@
 import javax.security.auth.callback.UnsupportedCallbackException;
 import javax.security.sasl.RealmCallback;
 
-public class JmxConnectorBuilder {
+public final class JmxConnectorBuilder {
 
   private static final Logger logger = Logger.getLogger(JmxConnectorBuilder.class.getName());
 
@@ -146,7 +147,7 @@ private Map<String, Object> buildEnv() {
                 }
               });
     } catch (ReflectiveOperationException e) {
-      logger.log(Level.WARNING, "SASL unsupported in current environment: " + e.getMessage());
+      logger.log(WARNING, "SASL unsupported in current environment: " + e.getMessage());
     }
     return env;
   }

jmx-scraper/src/main/java/io/opentelemetry/contrib/jmxscraper/JmxScraper.java

@@ -5,6 +5,12 @@
 
 package io.opentelemetry.contrib.jmxscraper;
 
+import static java.util.Arrays.asList;
+import static java.util.Collections.singletonList;
+import static java.util.Optional.ofNullable;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.SEVERE;
+
 import io.opentelemetry.api.GlobalOpenTelemetry;
 import io.opentelemetry.contrib.jmxscraper.config.JmxScraperConfig;
 import io.opentelemetry.contrib.jmxscraper.config.PropertiesCustomizer;
@@ -21,19 +27,15 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.Properties;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.management.MBeanServerConnection;
 import javax.management.remote.JMXConnector;
 
-public class JmxScraper {
+public final class JmxScraper {
   private static final Logger logger = Logger.getLogger(JmxScraper.class.getName());
   private static final String CONFIG_ARG = "-config";
   private static final String TEST_ARG = "-test";
@@ -55,7 +57,7 @@ public static void main(String[] args) {
     // set log format
     System.setProperty("java.util.logging.SimpleFormatter.format", "%1$tF %1$tT %4$s %5$s%n");
 
-    List<String> effectiveArgs = new ArrayList<>(Arrays.asList(args));
+    List<String> effectiveArgs = new ArrayList<>(asList(args));
     boolean testMode = effectiveArgs.remove(TEST_ARG);
 
     try {
@@ -73,16 +75,16 @@ public static void main(String[] args) {
       JmxScraperConfig scraperConfig = configCustomizer.getScraperConfig();
 
       long exportSeconds = scraperConfig.getSamplingInterval().toMillis() / 1000;
-      logger.log(Level.INFO, "metrics export interval (seconds) =  " + exportSeconds);
+      logger.log(INFO, "metrics export interval (seconds) =  " + exportSeconds);
 
       JmxMetricInsight service =
           JmxMetricInsight.createService(
               GlobalOpenTelemetry.get(), scraperConfig.getSamplingInterval().toMillis());
       JmxConnectorBuilder connectorBuilder =
           JmxConnectorBuilder.createNew(scraperConfig.getServiceUrl());
 
-      Optional.ofNullable(scraperConfig.getUsername()).ifPresent(connectorBuilder::withUser);
-      Optional.ofNullable(scraperConfig.getPassword()).ifPresent(connectorBuilder::withPassword);
+      ofNullable(scraperConfig.getUsername()).ifPresent(connectorBuilder::withUser);
+      ofNullable(scraperConfig.getPassword()).ifPresent(connectorBuilder::withPassword);
 
       if (scraperConfig.isRegistrySsl()) {
         connectorBuilder.withSslRegistry();
@@ -95,20 +97,20 @@ public static void main(String[] args) {
         jmxScraper.start();
       }
     } catch (ConfigurationException e) {
-      logger.log(Level.SEVERE, "invalid configuration: " + e.getMessage(), e);
+      logger.log(SEVERE, "invalid configuration: " + e.getMessage(), e);
       System.exit(1);
     } catch (InvalidArgumentException e) {
-      logger.log(Level.SEVERE, e.getMessage(), e);
+      logger.log(SEVERE, e.getMessage(), e);
       logger.info("Usage: java -jar <path_to_jmxscraper.jar> [-test] [-config <conf>]");
       logger.info("  -test           test JMX connection with provided configuration and exit");
       logger.info(
           "  -config <conf>  provide configuration, where <conf> is - for stdin, or <path_to_config.properties>");
       System.exit(1);
     } catch (IOException e) {
-      logger.log(Level.SEVERE, "Unable to connect ", e);
+      logger.log(SEVERE, "Unable to connect ", e);
       System.exit(2);
     } catch (RuntimeException e) {
-      logger.log(Level.SEVERE, e.getMessage(), e);
+      logger.log(SEVERE, e.getMessage(), e);
       System.exit(3);
     }
   }
@@ -119,14 +121,14 @@ private static boolean testConnection(JmxConnectorBuilder connectorBuilder) {
       MBeanServerConnection connection = connector.getMBeanServerConnection();
       Integer mbeanCount = connection.getMBeanCount();
       if (mbeanCount > 0) {
-        logger.log(Level.INFO, "JMX connection test OK");
+        logger.log(INFO, "JMX connection test OK");
         return true;
       } else {
-        logger.log(Level.SEVERE, "JMX connection test ERROR");
+        logger.log(SEVERE, "JMX connection test ERROR");
         return false;
       }
     } catch (IOException e) {
-      logger.log(Level.SEVERE, "JMX connection test ERROR", e);
+      logger.log(SEVERE, "JMX connection test ERROR", e);
       return false;
     }
   }
@@ -210,7 +212,7 @@ private void start() throws IOException {
 
     try (JMXConnector connector = client.build()) {
       MBeanServerConnection connection = connector.getMBeanServerConnection();
-      service.startRemote(getMetricConfig(config), () -> Collections.singletonList(connection));
+      service.startRemote(getMetricConfig(config), () -> singletonList(connection));
 
       running.set(true);
       logger.info("JMX scraping started");

jmx-scraper/src/main/java/io/opentelemetry/contrib/jmxscraper/config/JmxScraperConfig.java

@@ -5,21 +5,25 @@
 
 package io.opentelemetry.contrib.jmxscraper.config;
 
+import static java.util.Collections.emptyList;
+import static java.util.Collections.emptySet;
+import static java.util.Collections.unmodifiableList;
+import static java.util.Collections.unmodifiableSet;
+import static java.util.Locale.ROOT;
+
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigurationException;
 import java.io.InputStream;
 import java.time.Duration;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Locale;
 import java.util.Set;
 import java.util.logging.Logger;
 import javax.annotation.Nullable;
 
 /** This class keeps application settings */
-public class JmxScraperConfig {
+public final class JmxScraperConfig {
 
   private static final Logger logger = Logger.getLogger(JmxScraperConfig.class.getName());
 
@@ -49,9 +53,9 @@ public class JmxScraperConfig {
 
   private String serviceUrl = "";
 
-  private List<String> jmxConfig = Collections.emptyList();
+  private List<String> jmxConfig = emptyList();
 
-  private Set<String> targetSystems = Collections.emptySet();
+  private Set<String> targetSystems = emptySet();
 
   private TargetSystemSource targetSystemSource = TargetSystemSource.AUTO;
 
@@ -73,7 +77,7 @@ public enum TargetSystemSource {
 
     static TargetSystemSource fromString(String source) {
       try {
-        return TargetSystemSource.valueOf(source.toUpperCase(Locale.ROOT));
+        return TargetSystemSource.valueOf(source.toUpperCase(ROOT));
       } catch (IllegalArgumentException e) {
         throw new IllegalArgumentException("Invalid target system source: " + source, e);
       }
@@ -217,8 +221,8 @@ public static JmxScraperConfig fromConfig(ConfigProperties config) {
           "at least one of '" + JMX_TARGET_SYSTEM + "' or '" + JMX_CONFIG + "' must be set");
     }
 
-    scraperConfig.jmxConfig = Collections.unmodifiableList(jmxConfig);
-    scraperConfig.targetSystems = Collections.unmodifiableSet(new HashSet<>(targetSystem));
+    scraperConfig.jmxConfig = unmodifiableList(jmxConfig);
+    scraperConfig.targetSystems = unmodifiableSet(new HashSet<>(targetSystem));
 
     scraperConfig.username = config.getString("otel.jmx.username");
     scraperConfig.password = config.getString("otel.jmx.password");

jmx-scraper/src/main/java/io/opentelemetry/contrib/jmxscraper/config/PropertiesCustomizer.java

@@ -16,7 +16,7 @@
 import javax.annotation.Nullable;
 
 /** Customizer of default SDK configuration and provider of effective scraper config */
-public class PropertiesCustomizer implements Function<ConfigProperties, Map<String, String>> {
+public final class PropertiesCustomizer implements Function<ConfigProperties, Map<String, String>> {
 
   private static final Logger logger = Logger.getLogger(PropertiesCustomizer.class.getName());
 

jmx-scraper/src/main/java/io/opentelemetry/contrib/jmxscraper/config/PropertiesSupplier.java

@@ -11,7 +11,7 @@
 import java.util.function.Supplier;
 
 /** Configuration supplier for java properties */
-public class PropertiesSupplier implements Supplier<Map<String, String>> {
+public final class PropertiesSupplier implements Supplier<Map<String, String>> {
 
   private final Properties properties;
 

jmx-scraper/src/test/java/io/opentelemetry/contrib/jmxscraper/JmxScraperTest.java

@@ -5,15 +5,15 @@
 
 package io.opentelemetry.contrib.jmxscraper;
 
+import static java.util.Arrays.asList;
+import static java.util.Collections.emptyList;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 import io.opentelemetry.contrib.jmxscraper.config.JmxScraperConfig;
 import io.opentelemetry.contrib.jmxscraper.config.TestUtil;
 import java.io.IOException;
 import java.io.InputStream;
-import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.Properties;
 import org.junit.jupiter.api.Test;
@@ -32,7 +32,7 @@ void shouldThrowExceptionWhenInvalidCommandLineArgsProvided() {
 
   @Test
   void emptyArgumentsAllowed() throws InvalidArgumentException {
-    assertThat(JmxScraper.argsToConfig(Collections.emptyList()))
+    assertThat(JmxScraper.argsToConfig(emptyList()))
         .describedAs("empty config allowed to use JVM properties")
         .isEmpty();
   }
@@ -43,7 +43,7 @@ void shouldThrowExceptionWhenMissingProperties() {
   }
 
   private static void testInvalidArguments(String... args) {
-    assertThatThrownBy(() -> JmxScraper.argsToConfig(Arrays.asList(args)))
+    assertThatThrownBy(() -> JmxScraper.argsToConfig(asList(args)))
         .isInstanceOf(InvalidArgumentException.class);
   }
 
@@ -54,7 +54,7 @@ void shouldCreateConfig_propertiesLoadedFromFile() throws InvalidArgumentExcepti
     // Windows returns /C:/path/to/file, which is not a valid path for Path.get() in Java.
     String filePath =
         ClassLoader.getSystemClassLoader().getResource("validConfig.properties").getPath();
-    List<String> args = Arrays.asList("-config", filePath);
+    List<String> args = asList("-config", filePath);
 
     // When
     Properties parsedConfig = JmxScraper.argsToConfig(args);
@@ -73,7 +73,7 @@ void shouldCreateConfig_propertiesLoadedFromStdIn() throws InvalidArgumentExcept
         ClassLoader.getSystemClassLoader().getResourceAsStream("validConfig.properties")) {
       // Given
       System.setIn(stream);
-      List<String> args = Arrays.asList("-config", "-");
+      List<String> args = asList("-config", "-");
 
       // When
       Properties parsedConfig = JmxScraper.argsToConfig(args);