1. Check If Java is Already Installed java -version javac –version 2. Download Java Go to download page. 3. Install Java from downloaded .exe file 4. Configure Environment Variable Start Menu -> Search -> Edit System Environment Variables -> Environment Variable -> NEW -> Enter "JAVA_HOME" and "PATH_TO_JDK" 5. Test in Command Prompt echo %JAVA_HOME% …
Permutation – Java
What is the algorithm if we want to get the whole permutation combinations from a given array in java? I will introduce the algorithm in my own word: We take [a, b, c] as an example. We initialize an variable named as "cur", which means the current index we are concerning about how many different …
How to reverse String in java
Use the code below: // conversion from String object to StringBuffer StringBuffer sbr = new StringBuffer(str); // To reverse the string sbr.reverse();
How to convert Array to List
Plain Java public void givenUsingCoreJava_whenArrayConvertedToList_thenCorrect() { Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 }; List<Integer> targetList = Arrays.asList(sourceArray); } Commons Collection public void givenUsingCommonsCollections_whenArrayConvertedToList_thenCorrect() { Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 }; List<Integer> targetList = new ArrayList<>(6); CollectionUtils.addAll(targetList, sourceArray); } Guava public void givenUsingGuava_whenListConvertedToArray_thenCorrect() { List<Integer> sourceList = …
Hello World in Spring Boot
Build Maven Porject in Intellij Edit POM <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.example</groupId> <artifactId>myproject</artifactId> <version>0.0.1-SNAPSHOT</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.6.1</version> </parent> <!– Additional lines to be added here… –> Adding Classpath Dependencies <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> Write Main and Controller Run Program
TreeMap in Java
Introduction The TreeMap in Java is used to implement Map interface and NavigableMap along with the AbstractMap Class. The map is sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time, depending on which constructor is used. This proves to be an efficient way of sorting and …
How to run a JavaFX project with Scene Builder in intelliJ
1. Check JavaFX plugin 2. Check the JavaFX project 3. Check the necessary dependencies 4. Search "javaFX" and open in preference 5. Configuration path to scenebuilder, and open scenebuilder to import FXML file
Generics in Java
Generics mean parameterized types. The idea is to allow type (Integer, String, … etc, and user-defined types) to be a parameter to methods, classes, and interfaces. Using Generics, it is possible to create classes that work with different data types. For example: // A Simple Java program to show working of user defined // Generic …
How to fix “Caused by: java.lang.NoClassDefFoundErr”
Use code below to compile and run our program: javac -d . Caller.java java com.Caller
How to install JavaFX on Mac
The simplest way I have seen is to use brew: brew tap bell-sw/liberica brew install –cask liberica-jdk15-full Then we could use terminal at least to run our JavaFX program. However, I think here would be more setting steps if you wanna run it in some IDE.