Category: java Beanutils

Java BeanUtils – Querying Or Filtering Collections ”; Previous Next Description The collections of beans can be filtered in the commons-collections by using the interface Predicate and also provides either true or false value on the evaluation of an input object. There is a Predicate called BeanPropertyValueEqualsPredicate which will assess the set property value against the given value. Syntax public BeanPropertyValueEqualsPredicate(String propertyName, Object propertyValue) The above syntax has two parameters, which decides what property to be evaluated and what should be its expected value. It creates a Predicate for evaluating the target object and returns true if the value specified by propertyName is equal to the value specified by the propertyValue; otherwise it returns false. The property names are defined by org.apache.commons.beanutils.PropertyUtils and can be simple, indexed, nested or mapped. For instance, you can filter a collection of beans where myCar property is false: // create the closure BeanPropertyValueEqualsPredicate predicate = new BeanPropertyValueEqualsPredicate( “myCar”, Boolean.FALSE ); // filter the collection CollectionUtils.filter( myCollection, predicate ); The above code filters the ”myCollection” collection and returns the boolean value for the object”s myCar property. Print Page Previous Next Advertisements ”;

Java BeanUtils – Create Custom Converters ”; Previous Next Description BeanUtils package allows creating your own string object to convert for any java class and the registered converters can be used by all the BeanUtils methods. The following are the steps to create and register your own converter: First create a class which will implements the Converter interface and the java.lang.Class object of an application class (such as the class which need to be converted and incoming string value to be converted) should be accepted by convert() method. The instance of your converter class should be registered by calling ConvertUtils.register() method at the creation time of an application. Syntax public <T> T convert(Class<T> type, Object value); Parameters: T: It indicates desired result type. type: It indicates that data type to which the value should be converted. value: It indicates an input value to be converted The above method will either return the converted value or it will throw an exception, if conversion cannot be performed successfully. Print Page Previous Next Advertisements ”;