Improvement of CLI logging and error messages related to reflection.

cobigen-cli/cli/src/main/java/com/devonfw/cobigen/cli/CobiGenCLI.java

@@ -4,6 +4,7 @@
 import java.nio.file.Paths;
 import java.util.Arrays;
 
+import com.devonfw.cobigen.cli.constants.MessagesConstants;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -34,11 +35,21 @@ public static void main(String... args) {
     LOG.debug("Current working directory: {}", System.getProperty("user.dir"));
     CommandLine commandLine = new CommandLine(new CobiGenCommand());
     commandLine.registerConverter(Path.class, s -> Paths.get(s));
+    CommandLine.IExecutionExceptionHandler exceptionHandler = new CommandLine.IExecutionExceptionHandler() {
+      @Override
+      public int handleExecutionException(Exception e, CommandLine commandLine, CommandLine.ParseResult parseResult) throws Exception {
+        if (LOG.isDebugEnabled()) {
+          LOG.debug("Cobigen exited with exception: ", e);
+        } else {
+          LOG.error("An error occurred while executing CobiGen: {}", e.getMessage());
+        }
+        return 1;
+      }
+    };
+    commandLine.setExecutionExceptionHandler(exceptionHandler);
     int exitCode = commandLine.execute(args);
-    if (exitCode == 0) {
-      LOG.info("Success");
-    } else {
-      LOG.info("Failed");
+    if (exitCode != 0) {
+      LOG.error("Cobigen terminated in an unexpected manner. {}", (LOG.isDebugEnabled() ? "" : MessagesConstants.VERBOSE_HINT));
     }
     System.exit(exitCode);
   }

cobigen-cli/cli/src/main/java/com/devonfw/cobigen/cli/commands/CommandCommons.java

@@ -31,6 +31,8 @@ public Integer call() throws Exception {
 
     if (this.verbose) {
       CLILogger.setLevel(Level.DEBUG);
+    } else {
+      CLILogger.setLevel(Level.INFO);
     }
 
     return doAction();

cobigen-cli/cli/src/main/java/com/devonfw/cobigen/cli/commands/GenerateCommand.java

@@ -104,7 +104,6 @@ public Integer doAction() throws Exception {
     CobiGen cg = CobiGenUtils.initializeCobiGen(this.templatesProject);
 
     resolveTemplateDependencies();
-
     if (this.increments == null && this.templates != null) {
       Tuple<List<Object>, List<TemplateTo>> inputsAndArtifacts = preprocess(cg, TemplateTo.class);
       for (int i = 0; i < inputsAndArtifacts.getA().size(); i++) {
@@ -331,16 +330,20 @@ public <T extends GenerableArtifact> void generate(Path inputFile, Object input,
         inputFile);
     report = cg.generate(input, generableArtifacts, this.outputRootPath.toAbsolutePath(), false, (task, progress) -> {
     });
-    ValidationUtils.checkGenerationReport(report);
-    Set<Path> generatedJavaFiles = report.getGeneratedFiles().stream().filter(e -> e.getFileName().endsWith(".java"))
-        .collect(Collectors.toSet());
-    if (!generatedJavaFiles.isEmpty()) {
-      try {
-        ParsingUtils.formatJavaSources(generatedJavaFiles);
-      } catch (FormatterException e) {
-        LOG.warn(
-            "Generation was successful but we were not able to format your code. Maybe you will see strange formatting.");
+    boolean generationSuccess = ValidationUtils.checkGenerationReport(report);
+    if (generationSuccess) {
+      Set<Path> generatedJavaFiles = report.getGeneratedFiles().stream().filter(e -> e.getFileName().endsWith(".java"))
+          .collect(Collectors.toSet());
+      if (!generatedJavaFiles.isEmpty()) {
+        try {
+          ParsingUtils.formatJavaSources(generatedJavaFiles);
+        } catch (FormatterException e) {
+          LOG.warn(
+              "Generation was successful but we were not able to format your code. Maybe you will see strange formatting.");
+        }
       }
+    } else {
+      LOG.error("Generation not successful! {}", (LOG.isDebugEnabled() ? "" : MessagesConstants.VERBOSE_HINT));
     }
   }
 

cobigen-cli/cli/src/main/java/com/devonfw/cobigen/cli/constants/MessagesConstants.java

@@ -76,4 +76,9 @@ public class MessagesConstants {
    * Message constant: description of the custom-location option
    */
   public static final String CUSTOM_LOCATION_OPTION_DESCRIPTION = "Custom location where the unpacked templates will be stored.";
+
+  /**
+   * Message constant: hint for verbose mode.
+   */
+  public static final String VERBOSE_HINT = "For more info execute in verbose mode (-v).";
 }

cobigen-cli/cli/src/main/java/com/devonfw/cobigen/cli/utils/ValidationUtils.java

@@ -76,28 +76,30 @@ public static boolean isOutputRootPathValid(Path outputRootPath) {
    * Checks the generation report in order to find possible errors and warnings
    *
    * @param report the generation report returned by the CobiGen.generate method
+   * @return true if generation succeeded, false otherwise
    */
-  public static void checkGenerationReport(GenerationReportTo report) {
+  public static boolean checkGenerationReport(GenerationReportTo report) {
 
     for (String warning : report.getWarnings()) {
       LOG.debug("Warning: {}", warning);
     }
 
+    // Successful generation
     if (report.getErrors() == null || report.getErrors().isEmpty()) {
       LOG.info("Successful generation.");
-    } else {
-      if (LOG.isDebugEnabled() && report.getErrors().size() > 1) {
-        for (int i = 1; i < report.getErrors().size(); i++) {
-          LOG.error("Further reported error:", report.getErrors().get(i));
-        }
-      }
-      if (report.getErrors().get(0) instanceof CobiGenRuntimeException) {
-        throw report.getErrors().get(0);
+      return true;
+    }
+    // Unsuccesful generation, log error messages to user
+    // Log exceptions for devs in DEBUG
+    for (int i = 0; i < report.getErrors().size(); i++) {
+      RuntimeException e = report.getErrors().get(i);
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("Encountered an exception: ", e);
       } else {
-        throw new CobiGenRuntimeException("Generation failed. Enable debug mode to see the exceptions occurred.",
-            report.getErrors().get(0));
+        LOG.error("Error: {}", e.getMessage());
       }
     }
+    return false;
   }
 
   /**

cobigen-plugins/cobigen-templateengines/cobigen-tempeng-freemarker/src/main/java/com/devonfw/cobigen/tempeng/freemarker/FreeMarkerTemplateEngine.java

@@ -73,8 +73,21 @@ public void process(TextTemplate template, Map<String, Object> model, Writer out
         env.setLogTemplateExceptions(false); // no duplicate logging
         env.process();
       } catch (TemplateException e) {
+        // Get root cause
+        Throwable rootCause = e;
+        while (rootCause.getCause() != null && rootCause.getCause() != rootCause) {
+          rootCause = rootCause.getCause();
+        }
+        String detailedCause = "";
+
+        if (rootCause.getClass().getCanonicalName().contains("java.lang")) {
+          detailedCause = ". A problem with Reflection has likely occurred: " + "Exception of type: "
+              + rootCause.getClass().getCanonicalName() + " with message: " + rootCause.getMessage()
+              + ", please consider rebuilding your project as a possible fix.";
+        }
         throw new CobiGenRuntimeException("An error occurred while generating the template: "
-            + template.getAbsoluteTemplatePath() + " (FreeMarker v" + FreemarkerMetadata.VERSION + ")", e);
+            + template.getAbsoluteTemplatePath() + " (FreeMarker v" + FreemarkerMetadata.VERSION + ")" + detailedCause,
+            e);
       } catch (Throwable e) {
         throw new CobiGenRuntimeException("An unkonwn error occurred while generating the template: "
             + template.getAbsoluteTemplatePath() + " (FreeMarker v" + FreemarkerMetadata.VERSION + ")", e);

cobigen/cobigen-core/src/main/java/com/devonfw/cobigen/impl/generator/InputInterpreterImpl.java

@@ -104,8 +104,15 @@ private Object readInput(Path path, Charset inputCharset, Map<TriggerInterpreter
           "Was not able to read input {} with inputreader '{}' although it was reported to be most likely readable. Trying next input reader...",
           path, triggerInterpreter, e);
     } catch (Throwable e) {
-      LOG.debug("While reading the input {} with the inputreader {}, an exception occured. Trying next input reader...",
-          path, triggerInterpreter, e);
+      if (LOG.isDebugEnabled()) {
+        // Logs full exception for DEBUG
+        LOG.debug("While reading the input {} with the inputreader {}, an exception occured. Trying next input reader...",
+                path, triggerInterpreter, e);
+      } else {
+        // Only logs message as possible hint for user
+        LOG.warn("While reading the input {} with the inputreader {}, an exception occured: {} Trying next input reader...",
+                path, triggerInterpreter, e.getMessage());
+      }
     }
     return null;
   }