Add support for reloading resources in Gradle plugin

Usage:

$ gradle bootRun
...

Edit files in src/main/resources and see the changes live in a web app
(e.g. static resources in /static).

The old functionality of bootRun has been replaced (since it didn't add
a lot of value and also didn't expose any JMV argument setters of anything).
This new feature set is backed by any existing "run" task configuration.

In addition autodetects a main class if there is one in the project
sources, so no need for mainClassName = '...' in build.gradle.

Applies the 'application' plugin (so no need to declare that either).

Fixes gh-225

spring-boot-samples/spring-boot-sample-actuator/build.gradle

@@ -1,17 +1,16 @@
 buildscript {
+	ext {
+		springBootVersion = '0.5.0.BUILD-SNAPSHOT'
+	}
     repositories {
     	mavenLocal()
         maven { url "http://repo.springsource.org/libs-snapshot" }
     }
     dependencies {
-        classpath("org.springframework.boot:spring-boot-gradle-plugin:0.5.0.BUILD-SNAPSHOT")
+        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
     }
 }
 
-ext {
-	springBootVersion = '0.5.0.BUILD-SNAPSHOT'
-}
-
 apply plugin: 'java'
 apply plugin: 'eclipse'
 apply plugin: 'idea'

spring-boot-samples/spring-boot-sample-simple/build.gradle

@@ -1,16 +1,16 @@
 buildscript {
+	ext {
+		springBootVersion = '0.5.0.BUILD-SNAPSHOT'
+	}
     repositories {
     	mavenLocal()
         maven { url "http://repo.springsource.org/libs-snapshot" }
     }
     dependencies {
-        classpath("org.springframework.boot:spring-boot-gradle-plugin:0.5.0.BUILD-SNAPSHOT")
+        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
     }
 }
 
-ext {
-	springBootVersion = '0.5.0.BUILD-SNAPSHOT'
-}
 
 apply plugin: 'java'
 apply plugin: 'eclipse'

spring-boot-tools/spring-boot-gradle-plugin/src/main/groovy/org/springframework/boot/gradle/SpringBootPlugin.java

@@ -19,26 +19,29 @@ package org.springframework.boot.gradle;
 import org.gradle.api.Plugin;
 import org.gradle.api.Project;
 import org.gradle.api.artifacts.Dependency;
+import org.gradle.api.plugins.ApplicationPlugin;
 import org.gradle.api.plugins.BasePlugin;
 import org.gradle.api.plugins.JavaPlugin;
 import org.springframework.boot.gradle.task.Repackage;
-import org.springframework.boot.gradle.task.RunJar;
+import org.springframework.boot.gradle.task.RunApp;
 
 /**
  * Gradle 'Spring Boot' {@link Plugin}. Provides 2 tasks (bootRepackge and bootRun).
  * 
  * @author Phillip Webb
+ * @author Dave Syer
  */
 public class SpringBootPlugin implements Plugin<Project> {
 
 	private static final String REPACKAGE_TASK_NAME = "bootRepackage";
 
-	private static final String RUN_JAR_TASK_NAME = "bootRun";
+	private static final String RUN_APP_TASK_NAME = "bootRun";
 
 	@Override
 	public void apply(Project project) {
 		project.getPlugins().apply(BasePlugin.class);
 		project.getPlugins().apply(JavaPlugin.class);
+		project.getPlugins().apply(ApplicationPlugin.class);
 		project.getExtensions().create("springBoot", SpringBootPluginExtension.class);
 
 		// register BootRepackage so that we can use
@@ -46,14 +49,14 @@ public class SpringBootPlugin implements Plugin<Project> {
 		project.getExtensions().getExtraProperties().set("BootRepackage", Repackage.class);
 		Repackage packageTask = addRepackageTask(project);
 		ensureTaskRunsOnAssembly(project, packageTask);
-		addRunJarTask(project);
+		addRunAppTask(project);
 	}
 
-	private void addRunJarTask(Project project) {
-		RunJar runJarTask = project.getTasks().create(RUN_JAR_TASK_NAME, RunJar.class);
-		runJarTask.setDescription("Run the executable JAR/WAR");
+	private void addRunAppTask(Project project) {
+		RunApp runJarTask = project.getTasks().create(RUN_APP_TASK_NAME, RunApp.class);
+		runJarTask.setDescription("Run the project with support for auto-detecting main class and reloading static resources");
 		runJarTask.setGroup("Execution");
-		runJarTask.dependsOn(REPACKAGE_TASK_NAME);
+		runJarTask.dependsOn("assemble");
 	}
 
 	private Repackage addRepackageTask(Project project) {

spring-boot-tools/spring-boot-gradle-plugin/src/main/groovy/org/springframework/boot/gradle/task/RunApp.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2012-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.gradle.task;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.concurrent.Callable;
+
+import org.gradle.api.Action;
+import org.gradle.api.DefaultTask;
+import org.gradle.api.Project;
+import org.gradle.api.file.SourceDirectorySet;
+import org.gradle.api.internal.file.collections.SimpleFileCollection;
+import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.tasks.JavaExec;
+import org.gradle.api.tasks.SourceSet;
+import org.gradle.api.tasks.TaskAction;
+import org.springframework.boot.loader.tools.MainClassFinder;
+
+/**
+ * Run the project from Gradle.
+ * 
+ * @author Dave Syer
+ */
+public class RunApp extends DefaultTask {
+
+	private SourceSet main;
+
+	@TaskAction
+	public void runApp() {
+
+		final Project project = getProject();
+		JavaPluginConvention javaConvention = project.getConvention().getPlugin(
+				JavaPluginConvention.class);
+		javaConvention.getSourceSets().all(new Action<SourceSet>() {
+			public void execute(SourceSet set) {
+				if (SourceSet.MAIN_SOURCE_SET_NAME.equals(set.getName())) {
+					main = set;
+				}
+			};
+		});
+
+		final Set<File> allResources = new LinkedHashSet<File>();
+		if (main != null) {
+			SourceDirectorySet resources = main.getResources();
+			allResources.addAll(resources.getSrcDirs());
+		}
+
+		project.getTasks().withType(JavaExec.class, new Action<JavaExec>() {
+			@Override
+			public void execute(JavaExec exec) {
+				ArrayList<File> files = new ArrayList<File>(exec.getClasspath()
+						.getFiles());
+				files.addAll(0, allResources);
+				getLogger().info("Adding classpath: " + allResources);
+				exec.setClasspath(new SimpleFileCollection(files));
+				if (exec.getMain() == null) {
+					final String mainClass = findMainClass(main);
+					exec.setMain(mainClass);
+					exec.getConventionMapping().map("main", new Callable<String>() {
+						@Override
+						public String call() throws Exception {
+							return mainClass;
+						}
+					});
+					getLogger().info("Found main: " + mainClass);
+				}
+				exec.exec();
+			}
+		});
+
+	}
+
+	private String findMainClass(SourceSet main) {
+		if (main == null) {
+			return null;
+		}
+		getLogger().info("Looking for main in: " + main.getOutput().getClassesDir());
+		try {
+			return MainClassFinder.findMainClass(main.getOutput().getClassesDir());
+		} catch (IOException e) {
+			throw new IllegalStateException("Cannot find main class", e);
+		}
+	}
+
+}

spring-boot-tools/spring-boot-gradle-plugin/src/main/groovy/org/springframework/boot/gradle/task/RunJar.java

@@ -1,57 +0,0 @@
-/*
- * Copyright 2012-2013 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.springframework.boot.gradle.task;
-
-import java.io.File;
-
-import org.gradle.api.Action;
-import org.gradle.api.DefaultTask;
-import org.gradle.api.Project;
-import org.gradle.api.internal.file.FileResolver;
-import org.gradle.api.tasks.TaskAction;
-import org.gradle.api.tasks.bundling.Jar;
-import org.gradle.process.internal.DefaultExecAction;
-import org.gradle.process.internal.ExecAction;
-
-/**
- * Run Jar task. Run the built jar file from Gradle.
- * 
- * @author Dave Noel
- */
-public class RunJar extends DefaultTask {
-
-	private File file;
-
-	@TaskAction
-	public void runJar() {
-		Project project = getProject();
-		project.getTasks().withType(Jar.class, new Action<Jar>() {
-
-			@Override
-			public void execute(Jar archive) {
-				file = archive.getArchivePath();
-			}
-		});
-		if (file != null && file.exists()) {
-			ExecAction action = new DefaultExecAction(getServices().get(
-					FileResolver.class));
-			action.setExecutable(System.getProperty("java.home") + "/bin/java");
-			action.args("-jar", file);
-			action.execute();
-		}
-	}
-}