Skip to end of metadata
Go to start of metadata

You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 5 Next »

GroovyBeans are JavaBeans but using a much simpler syntax.
Here's an example:

Error rendering macro 'code': Invalid value specified for parameter 'lang'
import java.util.Date

class Customer {
    // properties
    @Property Integer id
    @Property String name
    @Property Date dob
    // sample code
    static void main(args) {
        def customer = new Customer(id:1, name:"Gromit", dob:new Date())
        println("Hello ${}")
Error rendering macro 'code': Invalid value specified for parameter 'lang'
Hello Gromit

Notice how the properties look just like public fields. You can also set named properties in a bean constructor in Groovy. In Groovy, fields and properties have been merged so that they act and look the same. So, the Groovy code above is equivalent to the following Java code:

Property and field rules

When Groovy is compiled to bytecode, the following rules are used.

  • If the property is private, then a Java field is used to represent the property.
  • If a public or protected property is declared (properties are public by default), then a public or protected getter and setter are created along with a private Java field.
  • If you don't declare getters or setters for public or protected properties, they are automatically created for you at the bytecode level.
  • If you create a public or protected property, you can overload any auto-created methods.

So, for example, you could create a read only property or a public read-only property with a protected setter like this:

Error rendering macro 'code': Invalid value specified for parameter 'lang'
class Foo {
    // read only property
    private String name
    public String getName() { return name }
    // read only property with protected setter
    @Property Integer amount
    protected void setAmount(Integer amount) { this.amount = amount }
    // dynamically typed property
    def cheese

Note that properties need <i>some</i> kind of identifier: variable type ("String"), the "def" keyword, or the "@property" keyword.

  • No labels