Example usage for org.apache.commons.digester3 Digester addSetProperty

Introduction

In this page you can find the example usage for org.apache.commons.digester3 Digester addSetProperty.

Prototype

public void addSetProperty(String pattern, String name, String value) 

Source Link

Document

Add a "set property" rule for the specified parameters.

Usage

From source file:org.apache.commons.digester3.examples.api.catalog.Main.java

private static void addRules(Digester d) {

    // --------------------------------------------------

    // when we encounter the root "catalog" tag, create an
    // instance of the Catalog class.
    ///*w  w w. java 2s.  c om*/
    // Note that this approach is different from the approach taken in
    // the AddressBook example, where an initial "root" object was
    // explicitly created and pushed onto the digester stack before
    // parsing started instead
    //
    // Either approach is fine.

    d.addObjectCreate("catalog", Catalog.class);

    // --------------------------------------------------

    // when we encounter a book tag, we want to create a Book
    // instance. However the Book class doesn't have a default
    // constructor (one with no arguments), so we can't use
    // the ObjectCreateRule. Instead, we use the FactoryCreateRule.

    BookFactory factory = new BookFactory();
    d.addFactoryCreate("catalog/book", factory);

    // and add the book to the parent catalog object (which is
    // the next-to-top object on the digester object stack).
    d.addSetNext("catalog/book", "addItem");

    // we want each subtag of book to map the text contents of
    // the tag into a bean property with the same name as the tag.
    // eg <title>foo</title> --> setTitle("foo")
    d.addSetNestedProperties("catalog/book");

    // -----------------------------------------------

    // We are using the "AudioVisual" class to represent both
    // dvds and videos, so when the "dvd" tag is encountered,
    // create an AudioVisual object.

    d.addObjectCreate("catalog/dvd", AudioVisual.class);

    // add this dvd to the parent catalog object

    d.addSetNext("catalog/dvd", "addItem");

    // We want to map every xml attribute onto a corresponding
    // property-setter method on the Dvd class instance. However
    // this doesn't work with the xml attribute "year-made", because
    // of the internal hyphen. We could use explicit CallMethodRule
    // rules instead, or use a version of the SetPropertiesRule that
    // allows us to override any troublesome mappings...
    //
    // If there was more than one troublesome mapping, we could
    // use the method variant that takes arrays of xml-attribute-names
    // and bean-property-names to override multiple mappings.
    //
    // For any attributes not explicitly mapped here, the default
    // processing is applied, so xml attribute "category" --> setCategory.

    d.addSetProperties("catalog/dvd", "year-made", "yearMade");

    // We also need to tell this AudioVisual object that it is actually
    // a dvd; we can use the ObjectParamRule to pass a string to any
    // method. This usage is a little artificial - normally in this
    // situation there would be separate Dvd and Video classes.
    // Note also that equivalent behaviour could be implemented by
    // using factory objects to create & initialise the AudioVisual
    // objects with their type rather than using ObjectCreateRule.

    d.addCallMethod("catalog/dvd", "setType", 1);
    d.addObjectParam("catalog/dvd", 0, "dvd"); // pass literal "dvd" string

    // Each tag of form "<attr id="foo" value="bar"/> needs to map
    // to a call to setFoo("bar").
    //
    // This is an alternative to the syntax used for books above (see
    // method addSetNestedProperties), where the name of the subtag
    // indicated which property to set. Using this syntax in the xml has
    // advantages and disadvantages both for the user and the application
    // developer. It is commonly used with the FactoryCreateRule variant
    // which allows the target class to be created to be specified in an
    // xml attribute; this feature of FactoryCreateRule is not demonstrated
    // in this example, but see the Apache Tomcat configuration files for
    // an example of this usage.
    //
    // Note that despite the name similarity, there is no link
    // between SetPropertyRule and SetPropertiesRule.

    d.addSetProperty("catalog/dvd/attr", "id", "value");

    // -----------------------------------------------

    // and here we repeat the dvd rules, but for the video tag.
    d.addObjectCreate("catalog/video", AudioVisual.class);
    d.addSetNext("catalog/video", "addItem");
    d.addSetProperties("catalog/video", "year-made", "yearMade");
    d.addCallMethod("catalog/video", "setType", 1);
    d.addObjectParam("catalog/video", 0, "video");
    d.addSetProperty("catalog/video/attr", "id", "value");
}

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