From 6e3bb64b1f0ff832d38bab321a590a4f91a4eb78 Mon Sep 17 00:00:00 2001
From: alemoles <alemolerio@gmail.com>
Date: Sun, 27 Nov 2022 19:28:44 -0300
Subject: [PATCH] BAEL-5981 - String Interpolation in Java (#13092)

---
 .../core-java-string-operations-5/pom.xml     |  6 ++
 .../StringInterpolationUnitTest.java          | 84 +++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 core-java-modules/core-java-string-operations-5/src/test/java/com/baeldung/string_interpolation/StringInterpolationUnitTest.java

diff --git a/core-java-modules/core-java-string-operations-5/pom.xml b/core-java-modules/core-java-string-operations-5/pom.xml
index d7eade0145..efb32c73b9 100644
--- a/core-java-modules/core-java-string-operations-5/pom.xml
+++ b/core-java-modules/core-java-string-operations-5/pom.xml
@@ -20,6 +20,11 @@
             <artifactId>commons-lang3</artifactId>
             <version>${apache.commons.lang3.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-text</artifactId>
+            <version>${commons-text.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -39,6 +44,7 @@
         <maven.compiler.source>11</maven.compiler.source>
         <maven.compiler.target>11</maven.compiler.target>
         <apache.commons.lang3.version>3.12.0</apache.commons.lang3.version>
+        <commons-text.version>1.10.0</commons-text.version>
     </properties>
 
 </project>
\ No newline at end of file
diff --git a/core-java-modules/core-java-string-operations-5/src/test/java/com/baeldung/string_interpolation/StringInterpolationUnitTest.java b/core-java-modules/core-java-string-operations-5/src/test/java/com/baeldung/string_interpolation/StringInterpolationUnitTest.java
new file mode 100644
index 0000000000..7b2fa2ce97
--- /dev/null
+++ b/core-java-modules/core-java-string-operations-5/src/test/java/com/baeldung/string_interpolation/StringInterpolationUnitTest.java
@@ -0,0 +1,84 @@
+package com.baeldung.string_interpolation;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.text.MessageFormat;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.commons.text.StringSubstitutor;
+import org.junit.jupiter.api.Test;
+
+public class StringInterpolationUnitTest {
+    private final String EXPECTED_STRING = "String Interpolation in Java with some Java examples.";
+
+    @Test
+    public void givenTwoString_thenInterpolateWithPlusSign() {
+        String EXPECTED_STRING = "String Interpolation in Java with some Java examples.";
+        String first = "Interpolation";
+        String second = "Java";
+        String result = "String " + first + " in " + second + " with some " + second + " examples.";
+        assertEquals(EXPECTED_STRING, result);
+    }
+
+    @Test
+    public void givenTwoString_thenInterpolateWithFormat() {
+        String first = "Interpolation";
+        String second = "Java";
+        String result = String.format("String %s in %s with some %s examples.", first, second, second);
+        assertEquals(EXPECTED_STRING, result);
+    }
+
+    @Test
+    public void givenTwoString_thenInterpolateWithFormatted() {
+        String first = "Interpolation";
+        String second = "Java";
+        String result = String.format("String %s in %s with some %s examples.", first, second, second);
+        assertEquals(EXPECTED_STRING, result);
+    }
+
+    @Test
+    public void givenTwoString_thenInterpolateWithFormatStringReference() {
+        String first = "Interpolation";
+        String second = "Java";
+        String result = String.format("String %1$s in %2$s with some %2$s examples.", first, second);
+        assertEquals(EXPECTED_STRING, result);
+    }
+
+    @Test
+    public void givenTwoString_thenInterpolateWithStringBuilder() {
+        String first = "Interpolation";
+        String second = "Java";
+        StringBuilder builder = new StringBuilder();
+        builder.append("String ")
+            .append(first)
+            .append(" in ")
+            .append(second)
+            .append(" with some ")
+            .append(second)
+            .append(" examples.");
+        String result = builder.toString();
+        assertEquals(EXPECTED_STRING, result);
+    }
+
+    @Test
+    public void givenTwoString_thenInterpolateWithMessageFormat() {
+        String first = "Interpolation";
+        String second = "Java";
+        String result = MessageFormat.format("String {0} in {1} with some {1} examples.", first, second);
+        assertEquals(EXPECTED_STRING, result);
+    }
+
+    @Test
+    public void givenTwoString_thenInterpolateWithStringSubstitutor() {
+        String baseString = "String ${first} in ${second} with some ${second} examples.";
+        String first = "Interpolation";
+        String second = "Java";
+        Map<String, String> parameters = new HashMap<>();
+        parameters.put("first", first);
+        parameters.put("second", second);
+        StringSubstitutor substitutor = new StringSubstitutor(parameters);
+        String result = substitutor.replace(baseString);
+        assertEquals(EXPECTED_STRING, result);
+    }
+}