Example Matchers
Examples are not limited to default settings. You can specify your own defaults for string matching, null handling, and property-specific settings by using the ExampleMatcher
, as shown in the following example:
Person person = new Person(); (1)
person.setFirstname("Dave"); (2)
ExampleMatcher matcher = ExampleMatcher.matching() (3)
.withIgnorePaths("lastname") (4)
.withIncludeNullValues() (5)
.withStringMatcherEnding(); (6)
Example<Person> example = Example.of(person, matcher); (7)
1 | Create a new instance of the domain object. |
2 | Set properties. |
3 | Create an ExampleMatcher to expect all values to match. It is usable at this stage even without further configuration. |
4 | Construct a new ExampleMatcher to ignore the lastname property path. |
5 | Construct a new ExampleMatcher to ignore the lastname property path and to include null values. |
6 | Construct a new ExampleMatcher to ignore the lastname property path, to include null values, and to perform suffix string matching. |
7 | Create a new Example based on the domain object and the configured ExampleMatcher . |
By default, the ExampleMatcher
expects all values set on the probe to match. If you want to get results matching any of the predicates defined implicitly, use ExampleMatcher.matchingAny()
.
You can specify behavior for individual properties (such as "firstname" and "lastname" or, for nested properties, "address.city"). You can tune it with matching options and case sensitivity, as shown in the following example:
ExampleMatcher matcher = ExampleMatcher.matching()
.withMatcher("firstname", endsWith())
.withMatcher("lastname", startsWith().ignoreCase());
}
Another way to configure matcher options is to use lambdas (introduced in Java 8). This approach creates a callback that asks the implementor to modify the matcher. You need not return the matcher, because configuration options are held within the matcher instance. The following example shows a matcher that uses lambdas:
ExampleMatcher matcher = ExampleMatcher.matching()
.withMatcher("firstname", match -> match.endsWith())
.withMatcher("firstname", match -> match.startsWith());
}
Queries created by Example
use a merged view of the configuration. Default matching settings can be set at the ExampleMatcher
level, while individual settings can be applied to particular property paths. Settings that are set on ExampleMatcher
are inherited by property path settings unless they are defined explicitly. Settings on a property patch have higher precedence than default settings. The following table describes the scope of the various ExampleMatcher
settings:
Setting | Scope |
---|---|
Null-handling |
|
String matching |
|
Ignoring properties |
Property path |
Case sensitivity |
|
Value transformation |
Property path |