Take into account Sonar comments

Author: thboileau

org.restlet/src/main/java/org/restlet/Request.java

@@ -590,7 +590,7 @@ public boolean isAsynchronous() {
      */
     @Override
     public boolean isConfidential() {
-        return (getProtocol() == null) ? false : getProtocol().isConfidential();
+        return getProtocol() != null && getProtocol().isConfidential();
     }
 
     /**

org.restlet/src/main/java/org/restlet/data/AuthenticationInfo.java

@@ -8,6 +8,7 @@
  */
 package org.restlet.data;
 
+import java.util.Objects;
 import org.restlet.engine.util.SystemUtils;
 
 /**
@@ -38,15 +39,6 @@ public class AuthenticationInfo {
     /** The optional response digest for mutual authentication. */
     private volatile String responseDigest;
 
-    /**
-     * Default constructor.
-     *
-     * @param nextNonce The next nonce value.
-     */
-    // public AuthenticationInfo(String nextNonce) {
-    // this(nextNonce, 0, );
-    // }
-
     /**
      * Constructor.
      *
@@ -72,51 +64,30 @@ public AuthenticationInfo(
     /** {@inheritDoc} */
     @Override
     public final boolean equals(final Object obj) {
-        boolean result = (obj == this);
-
-        // if obj == this no need to go further
-        if (!result) {
-            // if obj isn't a challenge request or is null don't evaluate
-            // further
-            if (obj instanceof AuthenticationInfo) {
-                final AuthenticationInfo that = (AuthenticationInfo) obj;
-                if (getNextServerNonce() != null) {
-                    result = getNextServerNonce().equals(that.getNextServerNonce());
-                } else {
-                    result = (that.getNextServerNonce() == null);
-                }
-
-                if (result) {
-                    result = (getNonceCount() == that.getNonceCount());
-                }
-
-                if (result) {
-                    if (getClientNonce() != null) {
-                        result = getClientNonce().equals(that.getClientNonce());
-                    } else {
-                        result = (that.getClientNonce() == null);
-                    }
-                }
-
-                if (result) {
-                    if (getQuality() != null) {
-                        result = getQuality().equals(that.getQuality());
-                    } else {
-                        result = (that.getQuality() == null);
-                    }
-                }
-
-                if (result) {
-                    if (getResponseDigest() != null) {
-                        result = getResponseDigest().equals(that.getResponseDigest());
-                    } else {
-                        result = (that.getResponseDigest() == null);
-                    }
-                }
+        if (obj == this) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+
+        if (obj instanceof final AuthenticationInfo that) {
+            if (!Objects.equals(getNextServerNonce(), that.getNextServerNonce())) {
+                return false;
+            }
+            if (getNonceCount() != that.getNonceCount()) {
+                return false;
+            }
+            if (!Objects.equals(getClientNonce(), that.getClientNonce())) {
+                return false;
+            }
+            if (!Objects.equals(getQuality(), that.getQuality())) {
+                return false;
             }
+            return Objects.equals(getResponseDigest(), that.getResponseDigest());
         }
 
-        return result;
+        return false;
     }
 
     /**

org.restlet/src/main/java/org/restlet/data/ChallengeMessage.java

@@ -158,7 +158,7 @@ public String getOpaque() {
      */
     public Series<Parameter> getParameters() {
         if (this.parameters == null) {
-            this.parameters = new Series<Parameter>(Parameter.class);
+            this.parameters = new Series<>(Parameter.class);
         }
 
         return this.parameters;

org.restlet/src/main/java/org/restlet/data/ChallengeRequest.java

@@ -83,7 +83,7 @@ public List<Reference> getDomainRefs() {
             synchronized (this) {
                 r = this.domainRefs;
                 if (r == null) {
-                    this.domainRefs = r = new CopyOnWriteArrayList<Reference>();
+                    this.domainRefs = r = new CopyOnWriteArrayList<>();
                     this.domainRefs.add(new Reference("/"));
                 }
             }
@@ -104,7 +104,7 @@ public List<String> getQualityOptions() {
             synchronized (this) {
                 r = this.qualityOptions;
                 if (r == null) {
-                    this.qualityOptions = r = new CopyOnWriteArrayList<String>();
+                    this.qualityOptions = r = new CopyOnWriteArrayList<>();
                     this.qualityOptions.add(QUALITY_AUTHENTICATION);
                 }
             }
@@ -143,17 +143,17 @@ public void setDomainRefs(List<Reference> domainRefs) {
      * @see #setDomainRefs(List)
      */
     public void setDomainUris(Collection<String> domainUris) {
-        List<Reference> domainRefs = null;
+        List<Reference> newDomainRefs = null;
 
         if (domainUris != null) {
-            domainRefs = new CopyOnWriteArrayList<Reference>();
+            newDomainRefs = new CopyOnWriteArrayList<>();
 
             for (String domainUri : domainUris) {
-                domainRefs.add(new Reference(domainUri));
+                newDomainRefs.add(new Reference(domainUri));
             }
         }
 
-        setDomainRefs(domainRefs);
+        setDomainRefs(newDomainRefs);
     }
 
     /**

org.restlet/src/main/java/org/restlet/data/CharacterSet.java

@@ -249,8 +249,10 @@ public CharacterSet(String name, String description) {
     /** {@inheritDoc} */
     @Override
     public boolean equals(Object object) {
-        return (object instanceof CharacterSet)
-                && getName().equalsIgnoreCase(((CharacterSet) object).getName());
+        if (object instanceof CharacterSet characterSet) {
+            return getName().equalsIgnoreCase(characterSet.getName());
+        }
+        return false;
     }
 
     @Override