Update Apache Shiro Example code (#2453)

* added updated example codes

* updated example code StringToCharStream

* deleted StringToCharStream.java locally

* removed redundant file

* added code for apache commons collection SetUtils

* refactored example code

* added example code for bytebuddy

* added example code for PCollections

* update pom

* refactored tests for PCollections

* spring security xml config

* spring security xml config

* remove redundant comment

* example code for apache-shiro

apache-shiro/src/main/java/com/baeldung/Main.java

@@ -2,22 +2,23 @@ package com.baeldung;
 
 import org.apache.shiro.SecurityUtils;
 import org.apache.shiro.authc.*;
-import org.apache.shiro.config.IniSecurityManagerFactory;
+import org.apache.shiro.mgt.DefaultSecurityManager;
 import org.apache.shiro.mgt.SecurityManager;
+import org.apache.shiro.realm.Realm;
+import org.apache.shiro.realm.text.IniRealm;
 import org.apache.shiro.session.Session;
 import org.apache.shiro.subject.Subject;
-import org.apache.shiro.util.Factory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class Main {
+
     private static final transient Logger log = LoggerFactory.getLogger(Main.class);
 
     public static void main(String[] args) {
 
-        Factory<SecurityManager> factory
-          = new IniSecurityManagerFactory("classpath:shiro.ini");
-        SecurityManager securityManager = factory.getInstance();
+        Realm realm = new MyCustomRealm();
+        SecurityManager securityManager = new DefaultSecurityManager(realm);
 
         SecurityUtils.setSecurityManager(securityManager);
         Subject currentUser = SecurityUtils.getSubject();

apache-shiro/src/main/resources/shiro.ini

@@ -1,3 +1,9 @@
-jdbcRealm = com.baeldung.MyCustomRealm
+[users]
+user = password,admin
+user2 = password2,editor
+user3 = password3,author
 
-securityManager.realms = $jdbcRealm
+[roles]
+admin = *
+editor = articles:*
+author = articles:compose,articles:save