backpointer should be singular

src/main/java/com/manning/hip/ch7/shortestpath/Map.java

@@ -33,24 +33,24 @@ protected void map(Text key, Text value, Context context)
       //
       int neighborDistance = node.getDistance() + 1;
 
-      // create the backpointers, which will append our own
+      // create the backpointer, which will append our own
       // node name to the list
       //
-      String backpointers = node.constructBackpointers(key.toString());
+      String backpointer = node.constructBackpointer(key.toString());
 
       // go through all the nodes and propagate the distance to them
       //
       for (int i = 0; i < node.getAdjacentNodeNames().length; i++) {
 
         String neighbor = node.getAdjacentNodeNames()[i];
 
-        // output the neighbor with the propagated distance and backpointers
+        // output the neighbor with the propagated distance and backpointer
         //
         outKey.set(neighbor);
 
         Node adjacentNode = new Node()
             .setDistance(neighborDistance)
-            .setBackpointers(backpointers);
+            .setBackpointer(backpointer);
 
         outValue.set(adjacentNode.toString());
         System.out.println(

src/main/java/com/manning/hip/ch7/shortestpath/Node.java

@@ -7,7 +7,7 @@
 
 public class Node {
   private int distance = INFINITE;
-  private String backpointers;
+  private String backpointer;
   private String[] adjacentNodeNames;
 
   public static int INFINITE = Integer.MAX_VALUE;
@@ -22,19 +22,19 @@ public Node setDistance(int distance) {
     return this;
   }
 
-  public String getBackpointers() {
-    return backpointers;
+  public String getBackpointer() {
+    return backpointer;
   }
 
-  public Node setBackpointers(String backpointers) {
-    this.backpointers = backpointers;
+  public Node setBackpointer(String backpointer) {
+    this.backpointer = backpointer;
     return this;
   }
 
-  public String constructBackpointers(String name) {
+  public String constructBackpointer(String name) {
     StringBuilder backpointers = new StringBuilder();
-    if (StringUtils.trimToNull(getBackpointers()) != null) {
-      backpointers.append(getBackpointers()).append(":");
+    if (StringUtils.trimToNull(getBackpointer()) != null) {
+      backpointers.append(getBackpointer()).append(":");
     }
     backpointers.append(name);
     return backpointers.toString();
@@ -62,7 +62,7 @@ public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append(distance)
         .append(fieldSeparator)
-        .append(backpointers);
+        .append(backpointer);
 
     if (getAdjacentNodeNames() != null) {
       sb.append(fieldSeparator)
@@ -81,7 +81,7 @@ public static Node fromMR(String value) throws IOException {
     }
     Node node = new Node()
         .setDistance(Integer.valueOf(parts[0]))
-        .setBackpointers(StringUtils.trimToNull(parts[1]));
+        .setBackpointer(StringUtils.trimToNull(parts[1]));
     if (parts.length > 2) {
       node.setAdjacentNodeNames(Arrays.copyOfRange(parts, 2,
           parts.length));

src/main/java/com/manning/hip/ch7/shortestpath/Reduce.java

@@ -52,7 +52,7 @@ public void reduce(Text key, Iterable<Text> values,
 
     if(shortestAdjacentNode != null) {
       originalNode.setDistance(minDistance);
-      originalNode.setBackpointers(shortestAdjacentNode.getBackpointers());
+      originalNode.setBackpointer(shortestAdjacentNode.getBackpointer());
     }
 
     outValue.set(originalNode.toString());
@@ -67,7 +67,7 @@ public void reduce(Text key, Iterable<Text> values,
           PathCounter.TARGET_NODE_DISTANCE_COMPUTED);
       counter.increment(minDistance);
       context.getCounter(PathCounter.PATH.toString(),
-          shortestAdjacentNode.getBackpointers()).increment(1);
+          shortestAdjacentNode.getBackpointer()).increment(1);
     }
   }
 }