[chore] add .gitignore

Author: m1a2st

.gitignore

@@ -0,0 +1,38 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

src/main/java/org/m1a2st/bean/BeanFactory.java

@@ -10,7 +10,7 @@
  */
 public class BeanFactory {
 
-    private Map<String, Object> beanMap = new HashMap<>();
+    private final Map<String, Object> beanMap = new HashMap<>();
 
     public void registerBean(String beanName, Object bean) {
         beanMap.put(beanName, bean);