Replace string concatenations with String.format (#3201)

* Define beans for handling different message types in a lean chat app

* Add class based spring beans configuration

* Define spring configuration in XML for constructor based bean injection

* Refactor package structure to separate constructor based bean injection code set from setter based bean injection code set

* Define configuration and classes specific to setter-based bean injection.

* Implement tests for constructor-based and setter-based bean injections

* develop codes for explaining type erasure

* Write unit tests for type erasure examples

* Remove evaluation article code

* Modify type erasure examples and unit tests

* Modify type erasure examples and unit tests

* Add expected exception in TypeErasureUnitTest

* Correct grammar in class name

* Implement File Manager app to demonstrate Polymorphism. Develop unit tests for Polymorphism article code

* Add examples for static polymorphism

* Change sysout statments to slf4j log info statements

* Add assertions and expected errors check on Test

* Add assertions and expected errors check on Test

* Correct compile time error of symbol not found

* Removed commented out non-compiling test.

* Replace string concatenations with String.format

* Replace string concatenations with String.format

core-java/src/main/java/com/baeldung/polymorphism/GenericFile.java

@@ -54,7 +54,7 @@ public class GenericFile {
     }
 
     public String getFileInfo() {
-        return "File Name: " + this.getName() + "\n" + "Extension: " + this.getExtension() + "\n" + "Date Created: " + this.getDateCreated() + "\n" + "Version: " + this.getVersion() + "\n";
+        return String.format("File Name: %s\n" + " Extension: %s\n" + " Date Created: %s\n" + " Version: %s\n", this.getName(), this.getExtension(), this.getDateCreated(), this.getVersion());
     }
 
     public Object read() {

core-java/src/main/java/com/baeldung/polymorphism/ImageFile.java

@@ -30,7 +30,7 @@ public class ImageFile extends GenericFile {
     }
 
     public String getFileInfo() {
-        return super.getFileInfo() + "Height: " + this.getHeight() + "\n" + "Width: " + this.getWidth();
+        return String.format(" %s Height: %d\n Width: %d", super.getFileInfo(), this.getHeight(), this.getWidth());
     }
 
     public String read() {

core-java/src/main/java/com/baeldung/polymorphism/TextFile.java

@@ -21,7 +21,7 @@ public class TextFile extends GenericFile {
     }
 
     public String getFileInfo() {
-        return super.getFileInfo() + "Word Count: " + wordCount;
+        return String.format(" %s Word Count: %d", super.getFileInfo(), wordCount);
     }
 
     public String read() {

core-java/src/test/java/com/baeldung/polymorphism/PolymorphismUnitTest.java

@@ -3,8 +3,6 @@ package com.baeldung.polymorphism;
 import static org.junit.Assert.*;
 
 import java.awt.image.BufferedImage;
-
-import org.junit.Ignore;
 import org.junit.Test;
 
 public class PolymorphismUnitTest {