In most Java projects you have a lot of classes written only for the purpose of holding some data.
If you need a bean class which can hold an int, a String and an instance of Foo you have to implement the following class:

public class BadExample {

    private int intValue;

    private String stringValue;

    private Foo foo;

    public Foo getFoo() {
        return this.foo;
    }

    public void setFoo(Foo foo) {
        this.foo = foo;
    }

    public int getIntValue() {
        return this.intValue;
    }

    public void setIntValue(int intValue) {
        this.intValue = intValue;
    }

    public String getStringValue() {
        return this.stringValue;
    }

    public void setStringValue(String stringValue) {
        this.stringValue = stringValue;
    }

}

Of course you could use a Map/HashMap to hold the data but you would lose type-safety:
Why not let Java do this boring job? Use Java Bean Proxy!

You only have to define the interface:

public interface NiceExample {

    Foo getFoo();

    void setFoo(Foo foo);

    int getIntValue();

    void setIntValue(int intValue);

    String getStringValue();

    void setStringValue(String stringValue);

}


The rest is done by Java Bean Proxy. To get an instance use ProxyFactory:

    NiceExample niceExample = ProxyFactory.getProxyInstance(NiceExample.class);
    niceExample.setIntValue(44);
    System.out.println(niceExample.getIntValue()); // Would of course result in "44"

ProxyFactory.getProxyInstance will return a dynamic (runtime) instance for NiceExample.class which implements hashcode, equals and toString correctly Additionally this runtime instance is Clone- and Serializable.

http://sourceforge.net/projects/beanproxy/

Have a lot of fun!