Techie Shah

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How to get the length of a Collection in the JSF expression language?

Problem How to get the length of a Collection in the JSF expression language? Solution There are two ways to get the length of a Collection i.e. List, Set, etc in the JSF expression language a) Define a method in the Bean In your bean declare a method to return the length of a collection @Named("MyBean ") @SessionScoped public class MyBean { private List list; . . . public int getCollectionLength() { return list.size(); } } b) Using Facelets,the length function #{ fn:length(MyBean.list) }

Hibernate - How to join unlink Entities?

Problem Hibernate - How to join unlink Entities? Solution In the latest version of Hibernate i.e. 5.1 onward, you can join the unlink entities like SQL style Query<Person> query = session.createQuery( "select p from Person p join Gender g on g.id = p.genderId ");

How to convert Enum to List of String in Java 8?

Problem How to convert Enum to List of String in Java 8? Solution Using the Java 8 Streams, its map and collect functions we can convert Enum to List of Strings Code import java.util.List; import java.util.stream.Collectors; import java.util.stream.Stream; public class EnumToStringList { public enum Alpha { A,B,C,D; } public static void main(String[] args) { List<String> strings = Stream.of(Alpha.values()).map( Alpha::name).collect( Collectors.toList()); } }

Java 13 - How to Concatenate Text Blocks

Introduction If you have not tried the Text Blocks feature introduced in Java 13 then the following post will help you to get started Java 13 - Example to use Text Blocks for Multi line String literals We can concatenate TextBlocks as we do with normal String as demonstrated in the following example. Example public class TextBlock { public static void main(String[] args) { String html = """ <html> <body> """ + """ <h1> Header One </h1> <p> Paragraph One </p> """ + """ <h1> Header One </h1> <p> Paragraph One </p> """ + """ </body> </html> """; S

Java 13 - Example to use Text Blocks for Multi line String literals

Introduction Lengthy Strings in Java code becomes hard to read. Multiline String literals can be XML, JSON, HTML, SQL queries, Hibernate or JPA queries, etc. Example String html = " <html>\r\n" + " <body>\r\n" + " <p>Hello, world</p>\r\n" + " </body>\r\n" + " </html>\r\n" ; Solution Thanks to the Text blocks feature introduced in Java 13. Now, these multiline String literals are more presentable in Java code. 1. Configuring Eclipse for Text Blocks 1.1 Requirments JDK 13 Eclipse Version: 2020-03 (4.15.0) 1.2 Eclipse Error 1 String literal is not properly closed by a double-quote 1.2.1 Solution Change the source of your program to 13 as shown in the following screenshot Java Source 13 1.3 Eclipse Error 2 Text Blocks is a preview feature and disabled by default. Use --enable-preview to enable 1.3.2 Eclipse Erro

JDK 14 - Target is not a JDK root. System library was not found.

Problem When I tried to add JDK 14 to my eclipse, the following error was shown Target is not a JDK root. System library was not found. Target is not a JDK root. System library was not found. My downloaded JDK folder was named as jdk-14 Solution I simply renamed my folder from jdk-14 to jdk-14.0 and it worked. The jdk 14 was successfully added to the Eclipse. Conclusion I t seems that sometimes Eclipse is not able to locate the jdk folder, renaming the folder refreshes the cache of Eclipse and then respective folder is located by Eclipse.

How to print XML inside div on HTML page?

Problem If you try to print the following XML on the HTML page, it will not be visible <website> <name>techieshah.com</name> <url>http://techieshah.com</url> </website> Solution Replace less than sign i.e. < with < Replace greater than sign i.e. > with >

Java - How to print Hibernate query parameters on console?

Introduction In this post, we will learn how to print Hibernate Query parameters using log4j. Requirments log4j-api-2.13.1.jar log4j-core-2.13.1.jar Step 1 Place the above two log4j jars inside the lib directory. For web applications, the lib directory is located inside the WEB-INF folder. Step 2 Create a file by the name of log4j2.xml and place it inside your src folder. Step 3 Place the following XML code inside the log4j2.xml file <configuration status="WARN"> <appenders> <console name="LogToConsole" target="SYSTEM_OUT"> <patternlayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"> </patternlayout></console> </appenders> <loggers> <logger additivity="false" level="debug" name="org.myapp"> <appenderref ref="LogToConsole"> &

JQuery - Uncaught ReferenceError: $ is not defined at

Exception Uncaught ReferenceError: $ is not defined at timer.js:14 Solution Please make sure that JQuery JS file is added in the HTML file JQuery JS file should be declared first than other JS files like <script src='https://code.jquery.com/jquery-3.4.1.min.js'></script> <script src='js/app.min.js'></script> <script src='js/timer.js'></script>

Java - How to convert an array of bytes i.e. byte[] to String ?

Introduction In this post, we will explore how to convert an array of bytes i.e. byte[] to String in Java. For this functionality, we will use the following constructor of java.lang.String class String (byte[] bytes, String enc) Example import java.nio.charset.StandardCharsets; public class ByteArrayToString { public static void main(String[] args) { byte[] bytes = "a quick fox jumps over the lazy dog".getBytes(); // convert the bytes to String System.out.println("bytes = " + bytes); System.out.println( "bytes.toString() = " + bytes.toString()); String myString = new String ( bytes , StandardCharsets.UTF_8); System.out.println("myString = " + myString); } } Output bytes = [B@41a4555e bytes.toString() = [B@41a4555e myString = a quick fox jumps over the lazy dog Conclusion In this post, we learned how to convert an array of bytes to String.