Generate LiquiBase changeLogs using Groovy

gistfile1.groovy

def writer = new FileWriter('sample2.xml')

// Define 2 tables
def tables =[]
def dept = new Table(tableName:'departments')
dept.columns << new Column(name:'id', type:'number(4,0)', nullable:false)
dept.columns << new Column(name:'dname', type:'varchar2(14)', remarks:'Department name')
tables << dept

def emp = new Table(tableName:'employees', remarks:'All employees known in HR system')
emp.columns << new Column(name:'id', type:'number(4,0)', nullable:false)
emp.columns << new Column(name:'ename', type:'varchar2(14)', remarks:'Full name')
emp.columns << new Column(name:'dept_id', type:'number(4,0)', nullable:false)
tables << emp

def cct = new ChangelogCreateTable(author: "james")
cct.generate(writer, tables)

class ChangelogCreateTable {
  String author
  def changesetId = 1
  def generate(writer, tables) {
    // MarkupBuilder cannot output an XML declaration, so this is a workaround
    def eol = System.properties.'line.separator'
    writer << '<?xml version="1.0" encoding="UTF-8" standalone="no"?>' << eol

    def xml = new groovy.xml.MarkupBuilder(writer)
    xml.databaseChangeLog( xmlns : "http://www.liquibase.org/xml/ns/dbchangelog/1.9"
                         , "xmlns:xsi" : "http://www.w3.org/2001/XMLSchema-instance"
                         , "xsi:schemaLocation" : "http://www.liquibase.org/xml/ns/dbchangelog/1.9 http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-1.9.xsd"
                         ) {
      tables.each { table ->
        changeSet(author: author, id : changesetId++) {
          createTable( table.getAttributes() ) {
            table.columns.each { col ->
              column(col.getAttributes() ) {
                if(col.getConstraintsAttributes()) {
                  constraints(col.getConstraintsAttributes())
                }
              }
            }
          }
        }
      }
    }
  }
}