https://jira.baeldung.com/browse/BAEL-7666 (#17633)

https://jira.baeldung.com/browse/BAEL-7666

Author: jsfan3

libraries-bytecode/pom.xml

@@ -62,6 +62,21 @@
             <scope>system</scope>
             <systemPath>${project.basedir}/src/main/resources/dinosaur-2.jar</systemPath>
         </dependency>-->
+        <dependency>
+            <groupId>org.teavm</groupId>
+            <artifactId>teavm-core</artifactId>
+            <version>${teavm.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.teavm</groupId>
+            <artifactId>teavm-classlib</artifactId>
+            <version>${teavm.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.teavm</groupId>
+            <artifactId>teavm-tooling</artifactId>
+            <version>${teavm.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -96,6 +111,7 @@
     <properties>
         <javaassist.version>3.29.2-GA</javaassist.version>
         <asm.version>5.2</asm.version>
+        <teavm.version>0.10.1</teavm.version>
     </properties>
 
 </project>

libraries-bytecode/src/main/java/com/baeldung/teavm/Calculator.java

@@ -0,0 +1,47 @@
+package com.baeldung.teavm;
+
+import org.teavm.jso.JSExport;
+import org.teavm.jso.dom.html.*;
+
+public class Calculator {
+
+    public static void main(String[] args) {
+        HTMLDocument document = HTMLDocument.current();
+        HTMLElement container = document.getElementById("calculator-container");
+
+        // Create input fields
+        HTMLInputElement input1 = (HTMLInputElement) document.createElement("input");
+        input1.setType("number");
+        container.appendChild(input1);
+
+        HTMLInputElement input2 = (HTMLInputElement) document.createElement("input");
+        input2.setType("number");
+        container.appendChild(input2);
+
+        // Create a button
+        HTMLButtonElement button = (HTMLButtonElement) document.createElement("button");
+        button.appendChild(document.createTextNode("Calculate Sum"));
+        container.appendChild(button);
+
+        // Create a div to display the result
+        HTMLElement resultDiv = document.createElement("div");
+        container.appendChild(resultDiv);
+
+        // Add click event listener to the button
+        button.addEventListener("click", (evt) -> {
+            try {
+                long num1 = Long.parseLong(input1.getValue());
+                long num2 = Long.parseLong(input2.getValue());
+                long sum = num1 + num2;
+                resultDiv.setTextContent("Result: " + sum);
+            } catch (NumberFormatException e) {
+                resultDiv.setTextContent("Please enter valid integer numbers.");
+            }
+        });
+    }
+
+    @JSExport
+    public static int sum(int a, int b) {
+        return a + b;
+    }
+}

libraries-bytecode/src/main/java/com/baeldung/teavm/TeaVMRunner.java

@@ -0,0 +1,22 @@
+package com.baeldung.teavm;
+
+import org.teavm.tooling.TeaVMTool;
+import org.teavm.tooling.TeaVMTargetType;
+import org.teavm.vm.TeaVMOptimizationLevel;
+
+import java.io.File;
+
+public class TeaVMRunner {
+    public static void main(String[] args) throws Exception {
+        TeaVMTool tool = new TeaVMTool();
+        tool.setTargetDirectory(new File("target/teavm"));
+        tool.setTargetFileName("calculator.js");
+        tool.setMainClass("com.baeldung.teavm.Calculator");
+        tool.setTargetType(TeaVMTargetType.JAVASCRIPT);
+        tool.setOptimizationLevel(TeaVMOptimizationLevel.ADVANCED);
+        tool.setDebugInformationGenerated(false);
+        tool.setIncremental(false);
+        tool.setObfuscated(true);
+        tool.generate();
+    }
+}

libraries-bytecode/src/test/java/com/baeldung/teavm/CalculatorUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.teavm;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class CalculatorUnitTest {
+
+    @Test
+    public void whenAddingTwoPositiveNumbers_thenCorrectSum() {
+        // when
+        int result = Calculator.sum(3, 7);
+
+        // then
+        assertEquals(10, result);
+    }
+
+    @Test
+    public void whenAddingNegativeAndPositiveNumber_thenCorrectSum() {
+        // when
+        int result = Calculator.sum(-5, 10);
+
+        // then
+        assertEquals(5, result);
+    }
+
+    @Test
+    public void whenAddingTwoNegativeNumbers_thenCorrectSum() {
+        // when
+        int result = Calculator.sum(-4, -6);
+
+        // then
+        assertEquals(-10, result);
+    }
+}