fixed a number of spotbugs issues

Author: Peter Hill

src/main/java/net/juniper/netconf/Device.java

@@ -1276,6 +1276,7 @@ public boolean isStrictHostKeyChecking() {
      *
      * @return the underlying {@link JSch} SSH client
      */
+    @SuppressWarnings("EI_EXPOSE_REP") // Defensive copy not feasible for JSch
     public JSch getSshClient() {
         // Defensive copy not possible; document that caller must not modify
         return sshClient;
@@ -1385,6 +1386,7 @@ public String getHostKeysFileName() {
      *
      * @return the {@link DocumentBuilder} in use
      */
+    @SuppressWarnings("EI_EXPOSE_REP") // Defensive copy not feasible for DocumentBuilder
     public DocumentBuilder getXmlBuilder() {
         // Defensive copy not possible; document that caller must not modify
         return xmlBuilder;
@@ -1416,6 +1418,7 @@ public String getHelloRpc() {
      *
      * @return active SSH subsystem channel, or {@code null}
      */
+    @SuppressWarnings("EI_EXPOSE_REP") // Defensive copy not feasible for active channel
     public ChannelSubsystem getSshChannel() {
         return sshChannel; // Defensive copy not feasible; caller must not modify
     }
@@ -1426,6 +1429,7 @@ public ChannelSubsystem getSshChannel() {
      *
      * @return SSH session, or {@code null}
      */
+    @SuppressWarnings("EI_EXPOSE_REP") // Defensive copy not feasible for active session
     public Session getSshSession() {
         return sshSession; // Defensive copy not feasible; caller must not modify
     }
@@ -1436,6 +1440,7 @@ public Session getSshSession() {
      *
      * @return active Netconf session, or {@code null}
      */
+    @SuppressWarnings("EI_EXPOSE_REP") // Defensive copy not feasible for active session
     public NetconfSession getNetconfSession() {
         return netconfSession; // Defensive copy not feasible; caller must not modify
     }
@@ -1451,6 +1456,7 @@ public NetconfSession getNetconfSession() {
      * @param sshChannel the SSH channel subsystem (must not be null)
      * @throws NullPointerException if sshChannel is null
      */
+    @SuppressWarnings("EI_EXPOSE_REP2") // Defensive copy not feasible for active channel
     public void setSshChannel(ChannelSubsystem sshChannel) {
         this.sshChannel = (ChannelSubsystem) Objects.requireNonNull(sshChannel);
     }
@@ -1464,6 +1470,7 @@ public void setSshChannel(ChannelSubsystem sshChannel) {
      * @param sshSession the SSH session (must not be null)
      * @throws NullPointerException if sshSession is null
      */
+    @SuppressWarnings("EI_EXPOSE_REP2") // Defensive copy not feasible for active session
     public void setSshSession(Session sshSession) {
         this.sshSession = Objects.requireNonNull(sshSession);
     }
@@ -1477,6 +1484,7 @@ public void setSshSession(Session sshSession) {
      * @param netconfSession the Netconf session (must not be null)
      * @throws NullPointerException if netconfSession is null
      */
+    @SuppressWarnings("EI_EXPOSE_REP2") // Defensive copy not feasible for active session
     public void setNetconfSession(NetconfSession netconfSession) {
         this.netconfSession = Objects.requireNonNull(netconfSession);
     }

src/main/java/net/juniper/netconf/LoadException.java

@@ -3,19 +3,50 @@
  All Rights Reserved
 
  Use is subject to license terms.
-
 */
 
 package net.juniper.netconf;
 
 import java.io.IOException;
 
-/** 
- * Describes exceptions related to load operation
+/**
+ * Exception thrown when a <em>load</em> RPC returns &lt;rpc-error&gt; or otherwise
+ * fails to complete successfully.
+ *
+ * <p>Three convenient constructors are provided so callers can supply:
+ * <ol>
+ *   <li>a human‑readable message only,</li>
+ *   <li>a message and root cause, or</li>
+ *   <li>just the root cause.</li>
+ * </ol>
  */
 public class LoadException extends IOException {
 
-    LoadException(String msg) {
-        super(msg);
+    /**
+     * Creates a {@code LoadException} with the supplied message.
+     *
+     * @param message description of the load failure
+     */
+    public LoadException(String message) {
+        super(message);
+    }
+
+    /**
+     * Creates a {@code LoadException} with a message and a root cause.
+     *
+     * @param message description of the load failure
+     * @param cause   underlying exception that triggered the failure
+     */
+    public LoadException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    /**
+     * Creates a {@code LoadException} that wraps an underlying cause.
+     *
+     * @param cause underlying exception that triggered the failure
+     */
+    public LoadException(Throwable cause) {
+        super(cause);
     }
 }

src/main/java/net/juniper/netconf/NetconfSession.java

@@ -229,9 +229,16 @@ public void loadXMLConfiguration(String configuration, String loadType) throws I
                 "</edit-config>" +
                 "</rpc>" +
                 NetconfConstants.DEVICE_PROMPT;
-        setLastRpcReply(getRpcReply(rpc));
-        if (hasError() || !isOK())
+        try {
+            setLastRpcReply(getRpcReply(rpc));
+        } catch (NetconfException e) {
+            // Propagate as a LoadException so the caller knows this happened
+            throw new LoadException("Load operation returned error.", e);
+        }
+
+        if (hasError() || !isOK()) {
             throw new LoadException("Load operation returned error.");
+        }
     }
 
     private void setHelloReply(final String reply) throws IOException {
@@ -285,9 +292,15 @@ public void loadTextConfiguration(String configuration, String loadType) throws
                 "</edit-config>" +
                 "</rpc>" +
                 NetconfConstants.DEVICE_PROMPT;
-        setLastRpcReply(getRpcReply(rpc));
-        if (hasError() || !isOK())
+        try {
+            setLastRpcReply(getRpcReply(rpc));
+        } catch (NetconfException e) {
+            throw new LoadException("Load operation returned error.", e);
+        }
+
+        if (hasError() || !isOK()) {
             throw new LoadException("Load operation returned error");
+        }
     }
 
     private String getConfig(String configTree) throws IOException {
@@ -392,21 +405,7 @@ public Hello getServerHello() {
     }
 
     /**
-     * Send an RPC (as String object) over the default Netconf session and get
-     * the response as an XML object.
-     *
-     * @param rpcContent RPC content to be sent. For example, to send an rpc
-     *                   &lt;rpc&gt;&lt;get-chassis-inventory/&gt;&lt;/rpc&gt;, the
-     *                   String to be passed can be
-     *                      "&lt;get-chassis-inventory/&gt;" OR
-     *                      "get-chassis-inventory" OR
-     *                      "&lt;rpc&gt;&lt;get-chassis-inventory/&gt;&lt;/rpc&gt;"
-     * @return RPC reply sent by Netconf server
-     * @throws org.xml.sax.SAXException If the XML Reply cannot be parsed.
-     * @throws java.io.IOException      If there are issues communicating with the netconf server.
-     */
-    /**
-     * Sends a raw RPC string, waits for the <rpc-reply>, and converts the
+     * Sends a raw RPC string, waits for the {@code &lt;rpc-reply&gt;}, and converts the
      * response to an {@link XML} object.
      * <p>
      * If the server includes any {@code &lt;rpc-error&gt;} elements, the call

src/main/java/net/juniper/netconf/element/RpcError.java

@@ -355,6 +355,13 @@ public static class Builder {
             private String errElement;
             private String noOpElement;
 
+            /**
+             * Creates a new builder instance with all fields initialized to null.
+             */
+            public Builder() {
+                // Default constructor - all fields start as null
+            }
+
             /**
              * Sets the name of the attribute that caused the error.
              *