Grails 3.x "Execution failed for task ':bootRun'"

When trying to run the grails application using the command "grails run-app", I encountered the following error:

 FAILURE: Build failed with an exception.  
 * What went wrong:  
 Execution failed for task ':bootRun'.  
 > Process 'command '/usr/java/jdk1.8.0_101/bin/java'' finished with non-zero exit value 1  

Even after looking at the stacktrace, it wasn't clear what was causing this error. And it seems from many google searches, that there are multiple reasons for getting such an error. But none of the solutions helped me.

As it turns out, it seems Grails 3.x doesn't like having Loggers declared in domain classes.

For example, I had the following class definition:

 class MyDomainClass {  
   Logger logger = Logger.getLogger(MyDomainClass.class)  
 }  

Once I removed the Logger declaration, then my application ran successfully. I know from experience, that previous versions of Grails 2.x allowed loggers in domain classes, but it seems it's not supported anymore?

I hope this helps somebody else from painful hours of debugging!

Executing command-line using Groovy

Running command-line executions through Groovy may at first seem straight-forward. But after thoroughly stepping through a real world example, I've found the need to write up a function  that will make this process a little easier, as shown in the code below:

      /**  
       * Execute on the command line  
       * @param command  
       * @return  
       */  
      private String execCommand(Object command, OutputStream os=null, Boolean doLog = true, Boolean ignoreStdErr = false) {  
           boolean doReturn = false  
           if (os == null) {  
                os = new ByteArrayOutputStream()  
                doReturn = true  
           }  
           ByteArrayOutputStream serr = new ByteArrayOutputStream()  
           if (doLog) {  
                logger.info("Running command: "+command)  
           }  
           Process p = command.execute()  
           p.consumeProcessOutput(os, serr)  
           p.waitFor()            
           //p.waitForProcessOutput()  
           //p.waitForOrKill(30000)  
           if (! ignoreStdErr && serr.size() > 0) {  
                logger.error(serr.toString())  
                throw new Exception(serr.toString())  
           }  
           if (doReturn)  
                return new String(os.toString())  
           else  
                return null  
      }  

Apache Camel and YAML processing example

I had trouble finding a full example of how to process YAML files using Apache Camel. So here's an example I've written:

         from("file:/home/philip/ga4gh_registration?move=archived")  
           .choice()  
             .when(header("CamelFileName").endsWith(".yml"))  
               .unmarshal()  
               .yaml(YAMLLibrary.SnakeYAML)  
               .process(new Processor() {  
                 @Override  
                 void process(Exchange exchange) throws Exception {  
                   String filename = exchange.getIn().getHeader("CamelFileName")  
                   logger.info("registerDataset: "+filename)  
                   def yamlObj = exchange.getIn().body  
                   logger.info("body="+yamlObj)  
                   logger.info("datasetName="+yamlObj.datasetName)  
                 }  
               })  
             .otherwise()  
               .log("Bad registration file: "+header("CamelFileName"))  
           .end()  

References:

http://camel.apache.org/yaml-data-format.html

Grails 3.x + SQLite

Grails 3.x does not provide support SQLite out of the box. But with little effort, we can get something working fairly quickly as shown in the steps I've outlined below:

SQLite JDBC

Add the following lines to build.gradle to add the dependency for SQLite JDBC:

build.gradle

 compile 'org.xerial:sqlite-jdbc:3.15.1'  

You can find other versions of the JDBC library from the maven repo here:

https://mvnrepository.com/artifact/org.xerial/sqlite-jdbc

SQLite Dialect

Clone and build the Github project to add the supporting classes for the SQLite Dialect from here:

https://github.com/gwenn/sqlite-dialect

Using maven to build, run the following command:

 mvn -DskipTests install  

Then take the resulting JAR file, sqlite-dialect-0.1.0.jar, under the /target folder and copy it to the lib folder in your Grails project.

In Grails 3.x, the lib folder no longer exists by default. Create a new folder in the root of your project

 mkdir $PROJECT_HOME/lib  

Copy the JAR file to the lib folder just created. For example:

 cp sqlite-dialect-0.1.0.jar /home/philip/agha/VariantStorage/lib  

Finally add the dependency of the JAR file in the build.gradle file:

 compile files('lib/sqlite-dialect-0.1.0.jar')  

Tying it together

Datasources are configured in application.yml:

 dataSource:  
   dbCreate: "update"  
   url: "jdbc:sqlite:/home/philip/ga4gh-server-env/registry.db"  
   logSql: "true"  
   dialect: "org.hibernate.dialect.SQLiteDialect"  
   driverClassName: "org.sqlite.JDBC"  

References:

http://stackoverflow.com/questions/19691940/grails-and-sqlite

http://stackoverflow.com/questions/32339950/how-to-add-a-non-mavenized-jar-dependency-to-a-grails-project-grails-3-x