jooby-run: allow to use a single class loader #3098

jknack · jknack · commit d5b1a5f0eb2b · 2023-08-26T14:03:52.000-03:00
- Use a single/fat class loader to run your application. This is required on complex project classpath where you start seeing weird reflection errors. This was the default mode in Jooby 2.x. The new model since 3.x uses a modular classloader which improves restart times and memory usage making it faster. Default is: `false`. - fix #3098
diff --git a/docs/asciidoc/dev-tools.adoc b/docs/asciidoc/dev-tools.adoc
@@ -110,6 +110,7 @@ The next example shows all the available options with their default values:
       <compileExtensions>java,kt</compileExtensions>               <3>
       <port>8080</port>                                            <4>
       <waitTimeBeforeRestart>500</waitTimeBeforeRestart>           <5>
+      <useSingleClassLoader>false</useSingleClassLoader>           <6>
     </configuration>
   </plugin>
   ...
@@ -139,6 +140,7 @@ joobyRun {
   compileExtensions = ["java", "kt"]                               <3>
   port = 8080                                                      <4>
   waitTimeBeforeRestart = 500                                      <5>
+  useSingleClassLoader = false                                     <6>
 }
 ----
 
@@ -147,6 +149,7 @@ joobyRun {
 <3> Source extensions. A change on these files trigger a compilation request, followed by a restart request.
 <4> Application port
 <5> How long to wait after last file change to restart. Default is: `500` milliseconds.
+<5> Use a single/fat class loader to run your application. This is required on complex project classpath where you start seeing weird reflection errors. This was the default mode in Jooby 2.x. The new model since 3.x uses a modular classloader which improves restart times and memory usage making it faster. Default is: `false`.
 
 For Maven and Gradle there are two variant `mvn jooby:testRun` and `./gradlew joobyTestRun` they work
 by expanding the classpath to uses the `test` scope or source set.
diff --git a/modules/jooby-gradle-plugin/src/main/java/io/jooby/gradle/RunTask.java b/modules/jooby-gradle-plugin/src/main/java/io/jooby/gradle/RunTask.java
@@ -62,6 +62,8 @@ public class RunTask extends BaseTask {
    */
   private Long waitTimeBeforeRestart;
 
+  private Boolean useSingleClassLoader;
+
   /**
    * Run task.
    *
@@ -85,6 +87,7 @@ public void run() throws Throwable {
           .orElseGet(() -> computeMainClassName(projects));
 
       JoobyRunOptions config = new JoobyRunOptions();
+      config.setUseSingleClassLoader(useSingleClassLoader = Boolean.TRUE);
       config.setMainClass(mainClass);
       config.setPort(port);
       if (compileExtensions != null) {
@@ -235,6 +238,16 @@ public void setRestartExtensions(List<String> restartExtensions) {
     this.restartExtensions = restartExtensions;
   }
 
+  @Input
+  @org.gradle.api.tasks.Optional
+  public Boolean isUseSingleClassLoader() {
+    return useSingleClassLoader;
+  }
+
+  public void setUseSingleClassLoader(Boolean useSingleClassLoader) {
+    this.useSingleClassLoader = useSingleClassLoader;
+  }
+
   /**
    * List of file extensions that trigger a compilation request. Compilation is done via Maven or
    * Gradle. Default is: <code>java</code> and <code>kt</code>.
diff --git a/modules/jooby-maven-plugin/src/main/java/io/jooby/maven/RunMojo.java b/modules/jooby-maven-plugin/src/main/java/io/jooby/maven/RunMojo.java
@@ -73,6 +73,9 @@ public class RunMojo extends BaseMojo {
 
   private boolean useTestScope;
 
+  @Parameter(property = "jooby.useSingleClassLoader")
+  private boolean useSingleClassLoader;
+
   @Override
   protected void doExecute(List<MavenProject> projects, String mainClass) throws Throwable {
     Maven maven = getMaven();
@@ -143,6 +146,7 @@ private JoobyRunOptions createOptions(String mainClass) {
     if (restartExtensions != null) {
       options.setRestartExtensions(restartExtensions);
     }
+    options.setUseSingleClassLoader(useSingleClassLoader);
     return options;
   }
 
@@ -184,6 +188,14 @@ public void setRestartExtensions(List<String> restartExtensions) {
     this.restartExtensions = restartExtensions;
   }
 
+  public boolean isUseSingleClassLoader() {
+    return useSingleClassLoader;
+  }
+
+  public void setUseSingleClassLoader(boolean useSingleClassLoader) {
+    this.useSingleClassLoader = useSingleClassLoader;
+  }
+
   protected void setUseTestScope(boolean useTestScope) {
     this.useTestScope = useTestScope;
   }
diff --git a/modules/jooby-run/src/main/java/io/jooby/run/JoobyRun.java b/modules/jooby-run/src/main/java/io/jooby/run/JoobyRun.java
@@ -374,9 +374,8 @@ public void start() throws Throwable {
               .map(Path::toString)
               .collect(Collectors.joining(File.pathSeparator));
       System.setProperty("jooby.run.classpath", classPathString);
-      var classloaderType = System.getProperty("jooby.run.classloader", "");
       JoobyModuleFinder finder;
-      if ("single".equals(classloaderType)) {
+      if (options.isUseSingleClassLoader()) {
         finder =
             new JoobySingleModuleLoader(
                 options.getProjectName(), classes, resources, dependencies, watchDirs.keySet());
diff --git a/modules/jooby-run/src/main/java/io/jooby/run/JoobyRunOptions.java b/modules/jooby-run/src/main/java/io/jooby/run/JoobyRunOptions.java
@@ -30,6 +30,8 @@ public class JoobyRunOptions {
 
   private Long waitTimeBeforeRestart = DEFAULT_WAIT_TIME_BEFORE_RESTART;
 
+  private boolean useSingleClassLoader;
+
   private static final long DEFAULT_WAIT_TIME_BEFORE_RESTART = 500L;
 
   static final long INITIAL_DELAY_BEFORE_FIRST_RESTART = 5000L;
@@ -88,6 +90,14 @@ public void setPort(Integer port) {
     this.port = port;
   }
 
+  public boolean isUseSingleClassLoader() {
+    return useSingleClassLoader;
+  }
+
+  public void setUseSingleClassLoader(boolean useSingleClassLoader) {
+    this.useSingleClassLoader = useSingleClassLoader;
+  }
+
   /**
    * How long to wait after last file change to restart. Default is: <code>500</code> milliseconds.
    *
