Class annotation used to assist in the creation of toString() methods in classes.
The @ToString annotation instructs the compiler to execute an
AST transformation which adds the necessary toString() method.
It allows you to write classes in this shortened form:
@ToString
class Customer {
String first, last
int age
Date since = new Date()
Collection favItems
private answer = 42
}
println new Customer(first:'Tom', last:'Jones', age:21, favItems:['Books', 'Games'])
Which will have this output:
Customer(Tom, Jones, 21, Wed Jul 14 23:57:14 EST 2010, [Books, Games])There are numerous options to customize the format of the generated output. E.g. if you change the first annotation to:
@ToString(includeNames=true)
Then the output will be:
Customer(first:Tom, last:Jones, age:21, since:Wed Jul 14 23:57:50 EST 2010, favItems:[Books, Games])Or if you change the first annotation to:
@ToString(includeNames=true,includeFields=true,excludes="since,favItems")
Then the output will be:
Customer(first:Tom, last:Jones, age:21, answer:42)If you have this example:
import groovy.transform.ToStringThen the output will be:@ToStringclass NamedThing { String name }@ToString(includeNames=true,includeSuper=true) class AgedThing extends NamedThing { int age } println new AgedThing(name:'Lassie', age:5)
AgedThing(age:5, super:NamedThing(Lassie))
@ToString can also be used in conjunction with @Canonical and @Immutable.
If you want to omit fields or properties referring to null, you can use the ignoreNulls flag:
import groovy.transform.ToString
@ToString(ignoreNulls = true) class NamedThing {
String name
}
println new NamedThing(name: null)
Which results in:
NamedThing()
By default the fully-qualified class name is used as part of the generated toString. If you want to exclude the package, you can set the includePackage flag to false, e.g.:
package my.company
import groovy.transform.ToString
@ToString(includePackage = false) class NamedThing {
String name
}
println new NamedThing(name: "Lassie")
Which results in:
NamedThing(name: Lassie)If the includePackage flag is
true (the default), then the output will be:
my.company.NamedThing(name: Lassie)
| Type | Name and Description |
|---|---|
boolean |
cacheWhether to cache toString() calculations. |
String[] |
excludesList of field and/or property names to exclude from generated toString. |
boolean |
ignoreNullsDon't display any fields or properties with value null. |
boolean |
includeFieldsInclude fields as well as properties in generated toString. |
boolean |
includeNamesWhether to include names of properties/fields in generated toString. |
boolean |
includePackageWhether to include the fully-qualified class name (i.e. including the package) or just the simple class name in the generated toString. |
boolean |
includeSuperWhether to include super in generated toString. |
String[] |
includesList of field and/or property names to include within the generated toString. |
Whether to cache toString() calculations. You should only set this to true if you know the object is immutable (or technically mutable but never changed). @default false
List of field and/or property names to exclude from generated toString. Must not be used if 'includes' is used. For convenience, a String with comma separated names can be used in addition to an array (using Groovy's literal list notation) of String values. @default {}
Don't display any fields or properties with value null. @default false
Include fields as well as properties in generated toString. @default false
Whether to include names of properties/fields in generated toString. @default false
Whether to include the fully-qualified class name (i.e. including the package) or just the simple class name in the generated toString. @default true
Whether to include super in generated toString. @default false
List of field and/or property names to include within the generated toString. Must not be used if 'excludes' is used. For convenience, a String with comma separated names can be used in addition to an array (using Groovy's literal list notation) of String values. @default {}