Example of defaultIfEmpty Observable example.

DefaultIfEmptyObservableExample.groovy

package com.charter.aesd.activationlogin.edge.service

import rx.Observable
import rx.functions.Func1
import rx.functions.Func3

/**
 * Created by rhasija on 1/14/16.
 */
class ObsTest {
    public static void main(String[] args) {
        def foo1 = Observable.just("123")
        def foo2 = Observable.just("456")
        def foo3 = Observable.error(new RuntimeException("edfrf"))

        def resultObs = Observable.zip(foo1, foo2, foo3, new Func3() {
            @Override
            Object call(Object o, Object o2, Object o3) {
                return "Inside Observable"
            }
        }).onErrorReturn(new Func1() {
            @Override
            Object call(Object o) {
                println "Error got called"
                return "error"
            }
        }).defaultIfEmpty(defaultMethod())

        println(resultObs.toBlocking().first())

    }

    static String defaultMethod() {
        println "defaultMethod"
        return "default"
    }
}