Make private fields final

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@754470 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/exception/NestableDelegate.java

@@ -65,7 +65,7 @@ public class NestableDelegate implements Serializable {
      * wrapping (which must be a {@link
      * org.apache.commons.lang.exception.Nestable} implementation).
      */
-    private Throwable nestable = null;
+    private final Throwable nestable;
     
     /**
      * Whether to print the stack trace top-down.

src/java/org/apache/commons/lang/exception/NestableError.java

@@ -40,13 +40,14 @@ public class NestableError extends Error implements Nestable {
      * The helper instance which contains much of the code which we
      * delegate to.
      */
+    // TODO make final
     protected NestableDelegate delegate = new NestableDelegate(this);
 
     /**
      * Holds the reference to the exception or error that caused
      * this exception to be thrown.
      */
-    private Throwable cause = null;
+    private final Throwable cause;
 
     /**
      * Constructs a new <code>NestableError</code> without specified
@@ -54,6 +55,7 @@ public class NestableError extends Error implements Nestable {
      */
     public NestableError() {
         super();
+        this.cause = null;
     }
 
     /**
@@ -64,6 +66,7 @@ public class NestableError extends Error implements Nestable {
      */
     public NestableError(String msg) {
         super(msg);
+        this.cause = null;
     }
 
     /**

src/java/org/apache/commons/lang/exception/NestableException.java

@@ -100,13 +100,14 @@ public class NestableException extends Exception implements Nestable {
      * The helper instance which contains much of the code which we
      * delegate to.
      */
+    // TODO make final
     protected NestableDelegate delegate = new NestableDelegate(this);
 
     /**
      * Holds the reference to the exception or error that caused
      * this exception to be thrown.
      */
-    private Throwable cause = null;
+    private final Throwable cause;
 
     /**
      * Constructs a new <code>NestableException</code> without specified
@@ -114,6 +115,7 @@ public class NestableException extends Exception implements Nestable {
      */
     public NestableException() {
         super();
+        this.cause = null;
     }
 
     /**
@@ -124,6 +126,7 @@ public class NestableException extends Exception implements Nestable {
      */
     public NestableException(String msg) {
         super(msg);
+        this.cause = null;
     }
 
     /**

src/java/org/apache/commons/lang/exception/NestableRuntimeException.java

@@ -44,13 +44,14 @@ public class NestableRuntimeException extends RuntimeException implements Nestab
      * The helper instance which contains much of the code which we
      * delegate to.
      */
+    // TODO make final
     protected NestableDelegate delegate = new NestableDelegate(this);
 
     /**
      * Holds the reference to the exception or error that caused
      * this exception to be thrown.
      */
-    private Throwable cause = null;
+    private final Throwable cause;
 
     /**
      * Constructs a new <code>NestableRuntimeException</code> without specified
@@ -58,6 +59,7 @@ public class NestableRuntimeException extends RuntimeException implements Nestab
      */
     public NestableRuntimeException() {
         super();
+        this.cause = null;
     }
 
     /**
@@ -68,6 +70,7 @@ public class NestableRuntimeException extends RuntimeException implements Nestab
      */
     public NestableRuntimeException(String msg) {
         super(msg);
+        this.cause = null;
     }
 
     /**