Ramya R Subramanian

Hi David,
             
Your Java Mock Exams Software seems exciting. A few questions

Do your mock exams include topic wise questions ?
How do you rate the toughness level of your questions with respect to the ones on the exams - is it similar/easier/harder .
Sometimes, the explanation to answers don't seem convincing. I see a technical customer support, how do they help ? Do you have a forum ?

regards,
Ramya

Hi Yakov & Anton,

Thank you for providing us a wonderful book. Looking forward to reading it.

I am trying to perform CRUD operations on DB from a spring BOOT application with REST API. I get the response in JSON. Any idea on how to parse from URL and display the data with Angular2
import { Component, OnInit } from '@angular/core'; import { Router } from '@angular/router'; @Component({    moduleId: module.id,    selector: 'my-address',    templateUrl: 'address.component.html',    styleUrls: ['address.component.css'] }) export class AddressComponent implements OnInit {  address1: Object[];  address2: Address[]; } export class Address {  add1: number;  add2: string; }
This is my typescript file. Any pointers on getting the response values in address1 or address2 object arrays from the request URL ?

regards,
Ramya

Hi Feranndo,

you have included Google Maps API many times in your code
<script async defer    src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDLQA97BhcJ6ccP6eAPp0ntUqMepGCoMJ0" type="text/javascript"> </script> <script async defer    src="https://www.google.com/jsapi?key=AIzaSyDLQA97BhcJ6ccP6eAPp0ntUqMepGCoMJ0" type="text/javascript"> </script> <script   type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"> </script> just try including it once like this:

<script async defer    src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDLQA97BhcJ6ccP6eAPp0ntUqMepGCoMJ0&callback=initMap">    </script>

My assumption based on this point from JLS:

If one of the second and third operands is of primitive type T, and the type of the other is the result of applying boxing conversion (§5.1.7) to T, then the type of the conditional expression is T.

Third operand type is (Integer.parseInt(String))  int which is Primitive type
The type of the second is got by applying the boxing conversion to int - Integer

So the resultant type of the conditional expression is int(primitive type) and then converted to Integer.Something like this happens
return Integer.valueOf(string == null?defaultValue.intValue():Integer.parseInt(string));
(Auto unboxing)defaultValue.intValue() gives the NPE. Using primitive types with ternary operator seems to be the best option to avoid such confusions.

Hi Harish,

Are you using an IDE to work out the snippets of code while studying ?If yes, then you will have a bit of trouble identifying which line will have a compilation error. So quit using IDE and use a text editor.

If one of the options is a "Compilation fails" then always check for a Compilation error when you start answering, it saves a lot of time. If you cant find one then go for the rest of the options.

Your scores are low, so just postpone taking the tests after you have revisited the concepts. Try to identify your problem areas and then get all the concepts clear. If suppose you are making mistakes in loops, try a number of questions in that alone until you are confident and have mastered it. Try to have a strategy for the areas that you need to improve... Keep track of the time. Make sure you finish the mock exams on time.

My view is don't overlearn the questions from the same book. You will just end up memorizing the answers involuntarily, giving you a false idea that you are good at it.Refer different books/guides outside your comfort zone.

Any mistake, no matter how trivial will cost you.So maybe you should practice on being more attentive.Go through the stories of the ranchers who have taken the exam.This is firsthand info, so will be extremely useful.All the best.

Thanks for the response. Yeah,thats true. But it doesnt work in certain cases. It throws an illegal argument exception, if @DBRef with lazy=true  is used with an Array.

Hello J Sharma & Ashish Sarin,

                                      Thank you for giving us a great book. Looking forward to reading it !..There are a few of issues with Spring Data and MongoDB, like there is no lazy loading with @DBRef. Do you see a work around to this?

regards,
Ramya

         

import java.util.*; import java.sql.*; // DOES NOT COMPILE LINE2 public class Conflicts { Date date;//LINE4 }
In page 12 of the book, due to the comment  //DOES NOT COMPILE, it seems to convey LINE2 does not compile. But actually LINE4 doesnt compile with the error msg "The type Date is ambiguous".

I assume you are trying to work on table per class hierarchy . In employee.hbm.xml  close the <class> tag at the end, before the tag </hibernate-mapping>.
</class> </hibernate-mapping>
and the type is "string" and not "String"
<discriminator column="EmpType" type="string" ></discriminator>
like here below
<?xml version='1.0' encoding='UTF-8'?>   <!DOCTYPE hibernate-mapping PUBLIC            "-//Hibernate/Hibernate Mapping DTD 3.0//EN"          "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">     <hibernate-mapping>    <class name="com.hibernateinheritancemapping.tableperhierarchy.Employee" table="EmpInheritanceMappingSingleTable" discriminator-value="emp">        <id name="id">            <generator class="increment"></generator>        </id>                <discriminator column="EmpType" type="string" ></discriminator>        <property name="name"></property>        <subclass name="com.hibernateinheritancemapping.tableperhierarchy.RegularEmployee" discriminator-value="empReg">        <property name="salary"></property>        <property name="bonus"></property>    </subclass>        <subclass name="com.hibernateinheritancemapping.tableperhierarchy.ContractEmployee" discriminator-value="empCont">        <property name="perHourPay"></property>        <property name="contractDuration"></property>    </subclass>    </class> </hibernate-mapping>

If you are using eclipse IDE, it might be defaulting to a Java 1.5.
Goto Project properties -> Java compiler -> Select compiler compliance to a higher level(or that of JRE you have installed)-> Apply.
and make sure to add that JRE to your build path. Project properties->Java Build Path->Libraries->Add Library->(select from your installed JRE's) ...and remove JRE 1.5, if it is present already.

And in the javatpoint tutorial, they have a oracle db and not mysql. check out the applicationContext.xml
<bean id="ds" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" /> <property name="url" value="jdbc:oracle:thin:@localhost:1521:xe" /> <property name="username" value="system" /> <property name="password" value="oracle" /> </bean>

you can also consider using batchUpdate in Spring JdbcTemplate. This link should give an idea

In the second class
s1=s1+" two";
Java uses pass by value, a copy of the reference is passed to the alter() method. And the above line creates a new string object with contents "one two", that the copy of the reference now points to. But the original reference in the start method still points to "one" and hence the output "one two one three".

These links should give you some idea
http://theopentutorials.com/post/uncategorized/passing-string-as-parameter-to-a-method/
search for "Passing Strings" in this link - http://www.cs.utoronto.ca/~dianeh/tutorials/params/
http://www.javaranch.com/campfire/StoryPassBy.jsp

Thank you very much for the precise answers.

Hi Ganesh,

Thank you for providing us a wonderful book. Looking forward to reading it. I have a few questions

Which do you think is preferable, (in exam perspective) a book that is specifically based on the certification objectives or a book which discusses all the possible topics under a certain objective. There are certain topics which are not explicitly stated in the objectives, but they turn out to be important. So what can we expect in the exam, are the questions strictly based on the objectives?

Do you maintain an errata for your OCP -8 Study Guide ?

regards,
Ramya

But it compiles.. I meant a code like this. Here Foo's play() will be called.
package a; public class Bar extends Foo { }
package a; public class Foo { void play() { System.out.println("In Foo"); } public static void main(String[] args) { Foo o = new b.Baz(); o.play();//In Foo } }
package b; public class Baz extends a.Bar { void play() { System.out.println("In Baz"); } }