chore: Remove accidental references to non Java 1.6 classes

Fixes #388.

agent/core/src/main/java/org/jolokia/converter/json/BeanExtractor.java

@@ -1,8 +1,8 @@
 package org.jolokia.converter.json;
 
-import java.beans.Transient;
 import java.io.OutputStream;
 import java.io.Writer;
+import java.lang.annotation.Annotation;
 import java.lang.reflect.*;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
@@ -208,13 +208,22 @@ private List<String> extractBeanAttributes(Object pValue) {
             if (!Modifier.isStatic(method.getModifiers()) &&
                 !IGNORE_METHODS.contains(method.getName()) &&
                 !isIgnoredType(method.getReturnType()) &&
-                !method.isAnnotationPresent(Transient.class)) {
+                !hasAnnotation(method, "java.beans.Transient")) {
                 addAttributes(attrs, method);
             }
         }
         return attrs;
     }
 
+    private boolean hasAnnotation(Method method, String annotation) {
+        for (Annotation anno : method.getAnnotations()) {
+            if (anno.annotationType().getName().equals(annotation)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     // Add attributes, which are taken from get methods to the given list
     @SuppressWarnings("PMD.UnnecessaryCaseChange")
     private void addAttributes(List<String> pAttrs, Method pMethod) {

agent/core/src/main/java/org/jolokia/util/JolokiaCipher.java

@@ -5,7 +5,7 @@
 import javax.crypto.spec.SecretKeySpec;
 
 import java.io.*;
-import java.nio.charset.StandardCharsets;
+import java.nio.charset.Charset;
 import java.security.*;
 import java.util.Random;
 
@@ -52,7 +52,7 @@ public JolokiaCipher(KeyHolder pKeyHolder) throws NoSuchAlgorithmException {
      * @return the encoded password
      */
     public String encrypt(final String pText) throws GeneralSecurityException {
-        byte[] clearBytes = pText.getBytes(StandardCharsets.UTF_8);
+        byte[] clearBytes = pText.getBytes(Charset.forName("UTF-8"));
         byte[] salt = getSalt(SALT_SIZE);
 
         Cipher cipher = createCipher(salt, Cipher.ENCRYPT_MODE);
@@ -91,7 +91,7 @@ public String decrypt(final String pEncryptedText) throws GeneralSecurityExcepti
         Cipher cipher = createCipher(salt, Cipher.DECRYPT_MODE);
         byte[] clearBytes = cipher.doFinal(encryptedBytes);
 
-        return new String(clearBytes, StandardCharsets.UTF_8);
+        return new String(clearBytes, Charset.forName("UTF-8"));
     }
 
     // =================================================================
@@ -149,7 +149,7 @@ private Cipher createCipher(byte[] salt, final int mode)
     public interface KeyHolder { String getKey(); };
 
     private byte[] getKeyAsBytes() {
-        return keyHolder.getKey().getBytes(StandardCharsets.UTF_8);
+        return keyHolder.getKey().getBytes(Charset.forName("UTF-8"));
     }
 
     private static class KeyHolderImpl implements KeyHolder {

agent/core/src/test/java/java/beans/Transient.java

@@ -0,0 +1,18 @@
+package java.beans;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * For testing purpose on Java 1.6
+ * @author roland
+ * @since 04.09.18
+ */
+@Target({METHOD})
+@Retention(RUNTIME)
+public @interface Transient {
+    boolean value() default true;
+}

agent/core/src/test/java/org/jolokia/converter/json/ObjectToJsonConverterTest.java

@@ -268,5 +268,4 @@ public void setTransientValue(String transientValue) {
             this.transientValue = transientValue;
         }
     }
-}
-
+}

pom.xml

@@ -750,6 +750,7 @@
         </pluginManagement>
       </build>
     </profile>
+
     <profile>
       <id>disable-javadoc-lint</id>
       <activation>