#1614 - Refactor DbMigration.generateMigration() to use System out to log key messages and throw UnknownResourcePathException

src/main/java/io/ebean/dbmigration/DbMigration.java

@@ -50,6 +50,11 @@ public interface DbMigration {
     throw new IllegalStateException("No service implementation found for DbMigration?");
   }
 
+  /**
+   * Set to false to suppress logging to System out.
+   */
+  void setLogToSystemOut(boolean logToSystemOut);
+
   /**
    * Set the path from the current working directory to the application resources.
    * <p>

src/main/java/io/ebeaninternal/dbmigration/DefaultDbMigration.java

@@ -72,6 +72,8 @@ public class DefaultDbMigration implements DbMigration {
 
   private static final String GENERATED_COMMENT = "THIS IS A GENERATED FILE - DO NOT MODIFY";
 
+  private boolean logToSystemOut = true;
+
   /**
    * Set to true if DefaultDbMigration run with online EbeanServer instance.
    */
@@ -316,6 +318,11 @@ public class DefaultDbMigration implements DbMigration {
         return generateDiff(request);
       }
 
+    } catch (UnknownResourcePathException e) {
+      logError("ERROR - " + e.getMessage());
+      logError("Check the working directory or change dbMigration.setPathToResources() value?");
+      return null;
+
     } finally {
       if (!online) {
         DbOffline.reset();
@@ -387,8 +394,7 @@ public class DefaultDbMigration implements DbMigration {
   private void writeExtraDdl(File migrationDir, DdlScript script) throws IOException {
 
     String fullName = repeatableMigrationName(script.isInit(), script.getName());
-
-    logger.info("writing repeatable script {}", fullName);
+    logger.debug("writing repeatable script {}", fullName);
 
     File file = new File(migrationDir, fullName);
     try (FileWriter writer = new FileWriter(file)) {
@@ -397,6 +403,30 @@ public class DefaultDbMigration implements DbMigration {
     }
   }
 
+  @Override
+  public void setLogToSystemOut(boolean logToSystemOut) {
+    this.logToSystemOut = logToSystemOut;
+  }
+
+  private void logError(String message) {
+    if (logToSystemOut) {
+      System.out.println("DbMigration> " + message);
+    } else {
+      logger.error(message);
+    }
+  }
+
+  private void logInfo(String message, Object value) {
+    if (value != null) {
+      message = String.format(message, value);
+    }
+    if (logToSystemOut) {
+      System.out.println("DbMigration> " + message);
+    } else {
+      logger.info(message);
+    }
+  }
+
   private String repeatableMigrationName(boolean init, String scriptName) {
     StringBuilder sb = new StringBuilder();
     if (init) {
@@ -416,12 +446,12 @@ public class DefaultDbMigration implements DbMigration {
 
     List<String> pendingDrops = request.getPendingDrops();
     if (!pendingDrops.isEmpty()) {
-      logger.info("Pending un-applied drops in versions {}", pendingDrops);
+      logInfo("Pending un-applied drops in versions %s", pendingDrops);
     }
 
     Migration migration = request.createDiffMigration();
     if (migration == null) {
-      logger.info("no changes detected - no migration written");
+      logInfo("no changes detected - no migration written", null);
       return null;
     } else {
       // there were actually changes to write
@@ -440,7 +470,7 @@ public class DefaultDbMigration implements DbMigration {
 
     List<String> pendingDrops = request.getPendingDrops();
     if (!pendingDrops.isEmpty()) {
-      logger.info("... remaining pending un-applied drops in versions {}", pendingDrops);
+      logInfo("... remaining pending un-applied drops in versions %s", pendingDrops);
     }
     return version;
   }
@@ -520,9 +550,9 @@ public class DefaultDbMigration implements DbMigration {
 
     String fullVersion = getFullVersion(request.nextVersion(), dropsFor);
 
-    logger.info("generating migration:{}", fullVersion);
+    logInfo("generating migration:%s", fullVersion);
     if (!request.dbinitMigration && !writeMigrationXml(dbMigration, request.modelDir, fullVersion)) {
-      logger.warn("migration already exists, not generating DDL");
+      logError("migration already exists, not generating DDL");
       return null;
     } else {
       if (!platforms.isEmpty()) {
@@ -627,7 +657,6 @@ public class DefaultDbMigration implements DbMigration {
     if (vanillaPlatform || databasePlatform == null) {
       // not explicitly set so use the platform of the server
       databasePlatform = server.getDatabasePlatform();
-      logger.trace("set platform to {}", databasePlatform.getName());
     }
     if (migrationConfig != null) {
       if (strictMode != null) {
@@ -713,13 +742,17 @@ public class DefaultDbMigration implements DbMigration {
 
     // path to src/main/resources in typical maven project
     File resourceRootDir = new File(pathToResources);
+    if (!resourceRootDir.exists()) {
+      String msg = String.format("Error - path to resources %s does not exist. Absolute path is %s", pathToResources, resourceRootDir.getAbsolutePath());
+      throw new UnknownResourcePathException(msg);
+    }
     String resourcePath = migrationConfig.getMigrationPath(dbinitMigration);
 
     // expect to be a path to something like - src/main/resources/dbmigration/model
     File path = new File(resourceRootDir, resourcePath);
     if (!path.exists()) {
       if (!path.mkdirs()) {
-        logger.debug("Unable to ensure migration directory exists at {}", path.getAbsolutePath());
+        logInfo("Warning - Unable to ensure migration directory exists at %s", path.getAbsolutePath());
       }
     }
     return path;
@@ -735,7 +768,7 @@ public class DefaultDbMigration implements DbMigration {
     }
     File modelDir = new File(migrationDirectory, migrationConfig.getModelPath());
     if (!modelDir.exists() && !modelDir.mkdirs()) {
-      logger.debug("Unable to ensure migration model directory exists at {}", modelDir.getAbsolutePath());
+      logInfo("Warning - Unable to ensure migration model directory exists at %s", modelDir.getAbsolutePath());
     }
     return modelDir;
   }

src/main/java/io/ebeaninternal/dbmigration/UnknownResourcePathException.java

@@ -0,0 +1,14 @@
+package io.ebeaninternal.dbmigration;
+
+/**
+ * Exception when db migration resource path does not exist.
+ * <p>
+ * Typically the working directory or pathToResources is incorrect.
+ * </p>
+ */
+public class UnknownResourcePathException extends RuntimeException {
+
+  public UnknownResourcePathException(String msg) {
+    super(msg);
+  }
+}