Dynamic Properties

POJO Plain Old Java Object. A regular Java object with no special restrictions other than those forced by the Java Language Specification and does not require any classpath. entries properties are bound by the schema of the POJO class definition, which means a property cannot be added without changing the class, and since changing the class requires restarting the space this can be a long and tiresome project.

Starting with version 8.0, GigaSpaces provides the Document API, which is schema free, and enables users to add properties freely without worrying about the schema. However, some users still prefer to continue working with POJO but would like to enjoy the benefits of dynamic properties.

Dynamic properties can be used with POJOs as well. This provides better interoperability between POJO and document entries, and provides excellent schema evolution support without switching from POJO to document.

Enabling

To enable dynamic properties, add a Map<String, Object> property to the relevant class and annotate it with @SpaceDynamicProperties. For example, the following Person class has two fixed properties (name and id), and an additional extraInfo property used to host the dynamic properties:

public class Person {
    public Person (){}
    private String name;
    private Integer id;
    private DocumentProperties extraInfo;

    public String getName() {return name}
    public void setName(String name) {this.name=name}

    @SpaceId
    public Integer getId() {return id;}
    public void setId(Integer id) {this.id=id;}

    @SpaceDynamicProperties
    public DocumentProperties getExtraInfo() {return extraInfo;}
    public void setExtraInfo(DocumentProperties extraInfo) {this.extraInfo=extraInfo;}
}

Usage

To write an entry with dynamic properties, simply populate them in the dynamic properties property. For example:

Person p = new Person();
p.setId(7);
p.setName("smith");
p.setExtraInfo(new DocumentProperties()
    .setProperty("email", "smith@foo.com")
    .setProperty("age", 30));
gigaSpace.write(p);

When the entry is read from the space, the dynamic properties will be populated.

You can have a getter and a setter for the newly added attributes with @SpaceExclude annotation on the getter field. This will instruct GigaSpaces to ignore this field when assembling the POJO field meta data:

public class Person {
    public Person (){}
    private String name;
    private Integer id;
    private DocumentProperties extraInfo;

    public String getName() {return name}
    public void setName(String name) {this.name=name}

    @SpaceId
    public Integer getId() {return id;}
    public void setId(Integer id) {this.id=id;}

    @SpaceDynamicProperties
    public DocumentProperties getExtraInfo() {return extraInfo;}
    public void setExtraInfo(DocumentProperties extraInfo) {this.extraInfo=extraInfo;}

    @SpaceExclude
    public String getEmail() {return (String)extraInfo.getProperty("email")}
    public void setEmail(String email) {extraInfo.setProperty("email",email)}

    @SpaceExclude
    public Integer getAge() {return (Integer.valueOf(extraInfo.getProperty("age")))}
    public void setAge(String age) {extraInfo.setProperty("age",age)}

}

Dynamic properties can also be used for matching. For example, suppose we want to get all persons who are not minors (age greater than 21) and email them something:

Person[] people = gigaSpace.readMultiple(new SQLQuery<Person>(
    Person.class, "age > 21"), Integer.MAX_VALUE);
for (Person person : people) {
    String email = person.getExtraInfo().getProperty("email");
    if (email != null)
        sendEmail(email);
}

Indexing

Dynamic properties can be indexed similar to fixed properties.