Spring 5 and JUNIT.

Let us try to put together some JUNITs with Spring 5 injection. One of the most challenging things of integrating JUnit and Spring was the role of the IDE. It is important to keep an eye on that. So here is the code we are going to look.

        @ContextConfiguration(classes = StreamsConfig.class)})
    public class StreamsFilterSampleTest {
      Logger LOG = getLogger(StreamsFilterSampleTest.class);
      StreamsFilterSample streamFilterStream;
      StreamstoListSample streamstoListSample;

      public void testStreamGroupBy() throws Exception {
        LOG.debug("Debugging method start ==> testStreamGroupBy " + "with parameter []");
        LOG.debug("Debugging method end ==> testStreamGroupBy " + "with parameter []");

We see the definition starts with Spring configuration initialization. The annotation

    @ContextConfiguration(classes = StreamsConfig.class)})

RunWith, we are annotating it to be Spring JUnit. The code block is getting initialized with configuration class of StreamConfig. Now let us take a look at the StreamConfig definition

    public class StreamsConfig {
    public static final Logger LOG = LoggerFactory.getLogger(StreamsConfig.class);
    StreamsFilterSample streamFilterStream;
      public StreamsConfig() {
        LOG.debug("Constructing Config");

We are autowiring an implementation class, StreamFilterSample. This is just a utility class and code goes something like this.

    public void streamGroupBy() {
    //3 apple, 2 banana, others 1
    List<Item> items = Arrays.asList(
        new Item(null, 10, new BigDecimal("20.00")),
        new Item("apple", 10, new BigDecimal("21.00")),
        new Item("apple", 10, new BigDecimal("22.00")),
        new Item("banana", 20, new BigDecimal("19.99")),
        new Item("orang", 10, new BigDecimal("29.99")),
        new Item("watermelon", 10, new BigDecimal("29.99")),
        new Item("papaya", 20, new BigDecimal("9.99")),
        new Item("apple", 10, new BigDecimal("9.99")),
        new Item("banana", 10, new BigDecimal("19.99")),
        new Item("apple", 20, new BigDecimal("9.99"))
    //group by price
    Map<BigDecimal, List<Item>> groupByPriceMap =
    Map<String, List<Item>> groupByNameMap =
        items.stream().filter(item -> item.getName() != null).collect(Collectors.groupingBy
    private static class Item {
    private String name;
    private int qty;
    private BigDecimal price;
    public Item(String name, int qty, BigDecimal price) {
      this.name = name;
      this.qty = qty;
      this.price = price;
    public Item(String name, BigDecimal price) {this.name = name;this.price = price;}
    public int getQty() {return qty;}
    public void setQty(int qty) {this.qty = qty;}
    public BigDecimal getPrice() {return price;}
    public void setPrice(BigDecimal price) {this.price = price;}
    public String getName() {return name;}
    public void setName(String name) {this.name = name;}

Now when we are running the JUnit, we have to make sure the @Test annotation is from the JUnit jar file. If you accidentally have the TestNG's @Test annotation, it will not be able to understand the configuration that we have in the JUnit header. Finally, remember to make sure the IDE is not making anything goofy where it pulled a wrong Annotation class. Here is a useful Stackoverflow discussion on this.

Reads and links May 1st to May 15th 2018

Links Thoughts
Day one course Like Shawn’s material. I did not buy it, as am already a power user of Dayone. If you thinking about journaling, I would think this would be wonderful
Concurrency and Parallelism Simple explanation about the most powerful concepts in programming.
Kids view Another great writeup from NPR for
Startup ideas This was a good overview if ur in a startup. Not sure if I can translate this in a big shop where I’m used to.
GDPR Am sure am not alone in getting all GDPR privacy update emails. This link was a good overview.

JAVA 9 takeWhile and doWhile

Trying to get my hands wet with Java 9. Looks like the streams have got another round of good method updates. Here in this gist we are trying to demonstrate the takeWhile and the dropWhile filter in the Java 9.

takeWhile method

Operates on a stream and in the code, we are trying to identify the songs that were from the year that is less than 2002. This condition qualifies only one record to be returned. The returned data is


dropWhile method

Aging this operates on a stream as well, and this one returns all the records whose album year is after 2002. So the we get back the following records.

1: https://gist.github.com/sathishjayapal/42b646b07f79b3e697909149ea27ae1f"https://gist.github.com/sathishjayapal/42b646b07f79b3e697909149ea27ae1f.js">







TED talk Friday., but wait is it.

I really enjoyed this commencement speech from David foster. This was from Tim Ferris news letter. The narration where the speech is talking about compassion. In the middle of the speech, I was thinking this is another left wing constructed speech talking about first world problems. I was wrong, and am glad that I heard the entire thing.

Free-code camp Inventory update solution

One other interesting problem with the inventory update challenge from freecodecamp. After this, it is going to be the modules for creating calculators and other challenges.

function updateInventoryWithArr(curInv, newInv) {
    var arr1 = curInv;
    var arr2 = newInv;
    var finalOutPutArr = [];
    var arr1Map = new Map();
    var arr2Map = new Map();
    var arr3Map = new Map();
    for (var j = 0; j < arr1.length; j++) {
        var data1 = arr1[j][1];
        var data2 = arr1[j][0];
        arr1Map.set(data1, data2);
        arr3Map.set(data1, data2);

    for (var i = 0; i < arr2.length; i++) {
        var keyVal = arr2[i][0];
        var lookupKey = arr2[i][1];
        var keyData = arr1Map.get(lookupKey);
        var sumVal;
        if (typeof keyData != 'undefined') {

            sumVal = keyVal + keyData;
            arr3Map.set(arr2[i][1], sumVal);
            arr2Map.set(sumVal, arr2[i][1]);
        } else {
            arr3Map.set(arr2[i][1], keyVal);
            arr2Map.set(keyVal, arr2[i][1]);


    var dataInf = Array.from(arr3Map);
    for (var k = 0; k < dataInf.length; k++) {
        finalOutPutArr.push([dataInf[k][1], dataInf[k][0]]);
    finalOutPutArr = finalOutPutArr.sort(function (a, b) {
        return a[1] > b[1]
    return finalOutPutArr;