This extends Part 4: Mockito & PowerMock for partially mocking private methods to mock “static” methods.
How to use both Spring JUnit and PowerMock runners?
By using the “@PowerMockRunnerDelegate” from the “powermock-module-junit4” jar.
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@RunWith(PowerMockRunner.class) @PowerMockRunnerDelegate(SpringJUnit4ClassRunner.class) |
So, need to use compatible “Mockito”
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Design principles interview questions & answers for Java developers so that you can expand your OOP skills to design robust Java apps Q25. What are the SOLID design principles? A25. SOLID is an abbreviation for 5 design principles. SRP (Single Responsibility Principle) If you have a class with calculation logic,...
Q1. What is HATEOAS? How does it provide state transition, scalability, and loose coupling? A1. HATEOAS (Hypermedia as the Engine of Application State) is considered the final level of REST. This means that each link is presumed to implement the standard REST verbs of GET, … Read more ›...
This tutorial extends Spring 4 MVC RESTful Web Service Beginner Tutorial step by step.
Controller that supports GET with path variable & POST methods
Step 1: The “AccountController.java” that has two additional methods to support requests like
GET: http://localhost:8080/simpleWeb/entry/v1/forecasting/account/123
POST: http://localhost:8080/simpleWeb/entry/v1/forecasting/account
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package com.mytutorial.controller; import java.math.BigDecimal; import org.springframework.http.HttpStatus; import org.springframework.http.MediaType; import org.springframework.http.ResponseEntity; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.ResponseBody; import com.mytutorial.model.Account; @Controller @RequestMapping("/v1/forecasting") public class AccountController { @RequestMapping(value = "/accounts", method = RequestMethod.GET, produces={MediaType.APPLICATION_JSON_VALUE}) public @ResponseBody Account[] getAccounts() { Account[] accounts = new Account[] { new Account("123", "John R", BigDecimal.valueOf(235.00)), new Account("345", "Peter J", BigDecimal.valueOf(2505.60)) }; return accounts; } @RequestMapping(value = "/account/{id}", method = RequestMethod.GET, produces={MediaType.APPLICATION_XML_VALUE}) public @ResponseBody Account getAccount(@PathVariable("id") String id) { //TODO: go to database and get the Account by id Account account = new Account(id, "John R", BigDecimal.valueOf(235.00)); return account; } @RequestMapping(value = "/account", method = RequestMethod.POST) public ResponseEntity<Account> saveAccount(@RequestBody Account account) { System.out.println("Creating:" + account); //TODO: Save to database return new ResponseEntity<Account>(account, HttpStatus.OK); } } |
Step 2: Package as simpleWeb.war and deploy to Tomcat’s “webapps”
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An excellent written test question to assess your Java multi-threading knowledge. Please practice it by doing it yourself.
Q. Review the code shown below and then answer the following questions.
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import java.util.ArrayList; import java.util.ArrayList; import java.util.List; public class WhatIsWrong { private static final int PRODUER_WAIT = 3; private static final int CONSUMER_WAIT = 2; private static boolean isDone = false; public static void main(String[] args) throws InterruptedException { List<Integer> list = new ArrayList<>(); Producer prod = new Producer(list); Consumer cons = new Consumer(list); prod.start(); cons.start(); Thread.sleep(30); isDone = true; } static class Producer extends Thread { private List<Integer> list; public Producer(List<Integer> list) { this.list = list; } public void run() { for (int i = 0; i < 10000; i++) { list.add(i); try { Thread.sleep(PRODUER_WAIT); } catch (InterruptedException e) { e.printStackTrace(); } } } } static class Consumer extends Thread { private List<Integer> list; public Consumer(List<Integer> list) { this.list = list; } public void run() { while (!isDone) { if (list.size() < 10) { try { Thread.sleep(CONSUMER_WAIT); } catch (InterruptedException e) { e.printStackTrace(); } } else { List<Integer> batch = new ArrayList<>(); for (Integer i : list) { batch.add(i); list.remove(i); } consume(batch); } } } private void consume(List<Integer> batch) { System.out.println("Printing numbers....."); System.out.println(batch); } } } |
Q1. What does the above code do?
Q2. What are the issues with the above code?
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Experienced developers know what tools to use to get the job done. I often forget code quality tool names like Sonar, FindBugs, Crucible, etc, penetration testing tools like Skipfish, and ETL tools like Datastage to name a few. So, it is worth refreshing your memory prior to job interviews. Eclipse/IntelliJ/NetBeans:...
Hibernate does require the same EntityManager to be available in order to lazily load objects. If you have no EntityManager, then you have no knowledge of the datastore. Once the transaction is committed the objects become detached, and you can’t lazy load detached objects. So, you need to lazily load...
Q. Complete the method “int startIndexOfLongestRun(String input)” that returns the start index of a character that has the longest consecutive count.
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public class MaxConsecutiveChar { public static int startIndexOfLongestRun(String input) { throw new RuntimeException("To be completed"); } public static void main(String[] args) { System.out.println(startIndexOfLongestRun("aaccccccaaaaa")); } } |
A. A map cannot be used here as the same character can repeated. For example, … Read more ›...
Q01: What is a JShell in Java? A01: JShell was introduced in Java 9, and it is a Read-Evaluate-Print-Loop (aka REPL). It provides an interactive shell for quickly prototyping, debugging, and learning Java and Java APIs. … Read more ›...
When using JMockit, there are 3 different ways of defining the expected result of the invocation of a mocked method. 1) result field, which we have been using the previous posts. It could be a value:
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new Expectations() {{ device.connect(anyString); result = "some result returned"; }}; |
or an exception:
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... new Expectations() {{ device.connect(anyString); result = new InterruptedException(); }}; ..... |
2) returns(Object…) method is a syntactic sugar for returning...
Tip #1: Tightly encapsulate your classes. A class generally contains data as well as methods, and is responsible for the integrity of its own data. The standard way to protect the data is to make it private, so that no other class can get direct access to it, … Read more...
Q. Write code to traverse a tree and return the sum of the values (Node.getValue()) of all nodes at the level N in the tree?
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package tree; import java.util.List; public interface Node<E> { E getValue(); List<Node<E>> getChildren(); } |
A. Let’s have a basic implementation of the above Node interface. … Read more ›...
Q. What is wrong with the following Java code? Explain what does the following code do? Explain if there is anything wrong with the following code? If there is something wrong, how will you go about fixing it?
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package what.is.wrong; public class WhatIsWrong1 extends Thread { public static Object lock1 = new Object(); public static Object lock2 = new Object(); public void method1() { synchronized (lock1) { delay(500); //some operation System.out.println("method1: " + Thread.currentThread().getName()); synchronized (lock2) { System.out.println("method1 is executing .... "); } } } public void method2() { synchronized (lock2) { delay(500); //some operation System.out.println("method2: " + Thread.currentThread().getName()); synchronized (lock1) { System.out.println("method2 is executing .... "); } } } @Override public void run() { method1(); method2(); } public static void main(String[] args) { WhatIsWrong1 thread1 = new WhatIsWrong1(); thread1.setName("worker-thread1"); WhatIsWrong1 thread2 = new WhatIsWrong1(); thread2.setName("worker-thread2"); thread1.start(); thread2.start(); } /** * The delay is to simulate some real operation happening. * @param timeInMillis */ private void delay(long timeInMillis) { try { Thread.sleep(timeInMillis); } catch (InterruptedException e) { e.printStackTrace(); } } } |
A. … Read more ›...
