Convert plugin code to Java as it is suggested by guidelines

pom.xml

@@ -37,10 +37,13 @@
 
   <groupId>io.jenkins.plugins</groupId>
   <artifactId>sentry</artifactId>
-  <version>6.30.0</version>
+  <version>6.30.4</version>
   <packaging>hpi</packaging>
-  <description>Integrates Jenkins with the Sentry error reporting service</description>
-  <url>http://wiki.jenkins-ci.org/display/JENKINS/Sentry+Plugin</url>
+
+
+  <properties>
+    <jenkins.version>2.387.3</jenkins.version>
+  </properties>
 
   <name>Sentry plugin</name>
 
@@ -73,6 +76,18 @@
     </dependency>
   </dependencies>
 
+<dependencyManagement>
+  <dependencies>
+    <dependency>
+      <groupId>io.jenkins.tools.bom</groupId>
+      <artifactId>bom-2.387.x</artifactId>
+      <version>2483.v3b_22f030990a_</version>
+      <scope>import</scope>
+      <type>pom</type>
+    </dependency>
+  </dependencies>
+</dependencyManagement>
+
   <repositories>
     <repository>
       <id>repo.jenkins-ci.org</id>
@@ -87,7 +102,20 @@
     </pluginRepository>
   </pluginRepositories>
 
-  <properties>
-    <jenkins.version>2.401.3</jenkins.version>
-  </properties>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jar-plugin</artifactId>
+        <configuration>
+          <archive>
+            <manifest>
+              <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
+              <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
+            </manifest>
+          </archive>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
 </project>

src/main/java/io/jenkins/plugins/sentry/SentryPlugin.java

@@ -0,0 +1,81 @@
+package io.jenkins.plugins.sentry;
+
+import hudson.Plugin;
+import io.sentry.Sentry;
+import io.sentry.jul.SentryHandler;
+
+import java.util.Enumeration;
+import java.util.logging.Handler;
+import java.util.logging.Level;
+import java.util.logging.LogManager;
+import java.util.logging.Logger;
+
+public class SentryPlugin extends Plugin {
+    private static final Logger LOG = Logger.getLogger(SentryPlugin.class.getName());
+
+    public void postInitialize() {
+        if (System.getenv("SENTRY_DSN") == null) {
+            LOG.warning("The `SENTRY_DSN` environment variable is not defined, not configuring Sentry");
+            return;
+        }
+
+        Sentry.init();
+        LOG.info("Sentry initialized");
+
+        if (System.getenv("SENTRY_NO_LOGWATCHER") == null) {
+            LOG.info("Running Sentry addLogWatcher");
+            addLogWatcher();
+        }
+    }
+
+    public void addLogWatcher() {
+        final SentryHandler sentry = new SentryHandler();
+        /* Default everything to the warning level, no need for INFO */
+        sentry.setMinimumEventLevel(Level.WARNING);
+
+        new Thread(() -> {
+            LOG.info("Waiting for 2 minutes for Jenkins to bootstrap before configuring Sentry");
+            try {
+                Thread.sleep(120_000); // Converted seconds to milliseconds
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+
+            while (true) {
+                Enumeration<String> enum_ = LogManager.getLogManager().getLoggerNames();
+                LOG.fine("Iterating over loggers");
+                while (enum_.hasMoreElements()) {
+                    String loggerName = enum_.nextElement();
+                    /* Avoid excessive warnings */
+                    /* https://issues.jenkins-ci.org/browse/JENKINS-46404 */
+                    if (!loggerName.equals("org.jenkinsci.plugins.durabletask.ProcessLiveness")) {
+                        LOG.fine("Checking logger: " + loggerName);
+                        Logger manager = LogManager.getLogManager().getLogger(loggerName);
+                        if (manager != null) {
+                            boolean found = false;
+                            for (Handler handler : manager.getHandlers()) {
+                                if (handler instanceof SentryHandler) {
+                                    found = true;
+                                    break;
+                                }
+                            }
+
+                            if (!found) {
+                                LOG.info("Adding Sentry to " + loggerName);
+                                manager.addHandler((Handler) sentry);
+                            }
+                        }
+                    }
+                }
+
+                // Sleep for five minutes in this thread, to make sure we are always
+                // adding Sentry to new loggers should they appear
+                try {
+                    Thread.sleep(300_000); // Converted 5 minutes to milliseconds
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }
+        }).start();
+    }
+}