A concept of "app name" for help purposes #93

* a better algorithm that detects jars

bootique/src/main/java/io/bootique/cli/meta/ApplicationIntrospector.java

@@ -0,0 +1,85 @@
+package io.bootique.cli.meta;
+
+import io.bootique.Bootique;
+
+import java.net.URL;
+import java.util.Map;
+
+/**
+ * A helper class to determine the app main class and user-freindly name.
+ */
+public class ApplicationIntrospector {
+
+    /**
+     * Returns application name that is the name of the main class derived from runtime stack.
+     *
+     * @return application name that is the name of the main class derived from runtime stack.
+     */
+    static String appNameFromRuntime() {
+        Class<?> main = mainClass();
+        String name = appNameFromJar(main);
+        return name != null ? name : appNameFromClassName(main);
+    }
+
+    private static String appNameFromClassName(Class<?> mainClass) {
+        // use full class name as app name...
+        return mainClass.getName();
+    }
+
+    private static String appNameFromJar(Class<?> mainClass) {
+
+        URL url;
+        try {
+            url = mainClass.getProtectionDomain().getCodeSource().getLocation();
+        } catch (Exception e) {
+            return null;
+        }
+
+        String urlString = url.toExternalForm();
+
+        // e.g. the app is started from an unpacked .jar
+        if (!urlString.endsWith(".jar")) {
+            return null;
+        }
+
+        int slash = urlString.lastIndexOf('/');
+        return slash < 0 && slash >= urlString.length() - 1 ? urlString : urlString.substring(slash + 1);
+    }
+
+
+    /**
+     * Returns the name of the app main class. If it can't be found, return 'io.bootique.Bootique'.
+     *
+     * @return the name of the app main class.
+     */
+    static Class<?> mainClass() {
+
+        for (Map.Entry<Thread, StackTraceElement[]> stackEntry : Thread.getAllStackTraces().entrySet()) {
+
+            // thread must be called "main"
+            if ("main".equals(stackEntry.getKey().getName())) {
+
+                StackTraceElement[] stack = stackEntry.getValue();
+                StackTraceElement bottom = stack[stack.length - 1];
+
+                // method must be called main
+                if ("main".equals(bottom.getMethodName())) {
+
+                    try {
+                        return Class.forName(bottom.getClassName());
+                    } catch (ClassNotFoundException e) {
+                        // can't load class for some reason...
+                        return Bootique.class;
+                    }
+
+                } else {
+                    // no other ideas where else to look for main...
+                    return Bootique.class;
+                }
+            }
+        }
+
+        // failover...
+        return Bootique.class;
+    }
+}

bootique/src/main/java/io/bootique/cli/meta/CliApplication.java

@@ -1,10 +1,7 @@
 package io.bootique.cli.meta;
 
-import io.bootique.Bootique;
-
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Map;
 
 /**
  * Metadata for the app application command invocation structure.
@@ -33,46 +30,6 @@ public static Builder builder(String name, String description) {
         return new Builder().name(name).description(description);
     }
 
-    /**
-     * Returns application name that is the name of the main class derived from runtime stack.
-     *
-     * @return application name that is the name of the main class derived from runtime stack.
-     */
-    static String appNameFromRuntime() {
-
-        String main = mainClass();
-        int dot = main.lastIndexOf('.');
-        return dot >= 0 && dot < main.length() - 1 ? main.substring(dot + 1) : main;
-    }
-
-    /**
-     * Returns the name of the app main class. If it can't be found, return 'io.bootique.Bootique'.
-     *
-     * @return the name of the app main class.
-     */
-    static String mainClass() {
-
-        for (Map.Entry<Thread, StackTraceElement[]> stackEntry : Thread.getAllStackTraces().entrySet()) {
-
-            // thread must be called "main"
-            if ("main".equals(stackEntry.getKey().getName())) {
-
-                StackTraceElement[] stack = stackEntry.getValue();
-                StackTraceElement bottom = stack[stack.length - 1];
-
-                // method must be called main
-                if ("main".equals(bottom.getMethodName())) {
-                    return bottom.getClassName();
-                } else {
-                    // no other ideas where else to look for main...
-                    return Bootique.class.getName();
-                }
-            }
-        }
-
-        // failover...
-        return Bootique.class.getName();
-    }
 
     public Collection<CliCommand> getCommands() {
         return commands;
@@ -100,7 +57,7 @@ public Builder name(String name) {
         }
 
         public Builder defaultName() {
-            return name(CliApplication.appNameFromRuntime());
+            return name(ApplicationIntrospector.appNameFromRuntime());
         }
 
         public Builder description(String description) {

bootique/src/test/java/io/bootique/cli/meta/CliApplicationTest.java → bootique/src/test/java/io/bootique/cli/meta/ApplicationIntrospectorTest.java

@@ -4,32 +4,29 @@
 import org.junit.Assert;
 import org.junit.Test;
 
-import static org.junit.Assert.assertEquals;
-
-public class CliApplicationTest {
+public class ApplicationIntrospectorTest {
 
     @Test
     public void testMainClass() {
 
-        String mainClassName = CliApplication.mainClass();
+        Class<?> mainClass = ApplicationIntrospector.mainClass();
 
         // TODO: until https://github.com/bootique/bootique/issues/52 is available,
         // we can't make an exact assertion here, as tests can be started from different IDEs, etc.
 
-        Assert.assertNotNull(mainClassName);
-        Assert.assertNotEquals(Bootique.class.getName(), mainClassName);
+        Assert.assertNotNull(mainClass);
+        Assert.assertNotEquals(Bootique.class, mainClass);
     }
 
     @Test
     public void testAppNameFromRuntime() {
 
-        String name = CliApplication.appNameFromRuntime();
+        String name = ApplicationIntrospector.appNameFromRuntime();
 
         // TODO: until https://github.com/bootique/bootique/issues/52 is available,
         // we can't make an exact assertion here, as tests can be started from different IDEs, etc.
 
         Assert.assertNotNull(name);
-        assertEquals(-1, name.indexOf('.'));
-        Assert.assertNotEquals(Bootique.class.getSimpleName(), name);
+        Assert.assertNotEquals("Bootique", name);
     }
 }