PrettyPrinter.java

package org.batfish.common.util;

import java.util.LinkedList;
import java.util.TreeMap;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

public class PrettyPrinter {

   public static String print(String prefixStr, JsonDiff jsonDiff) {
      final StringBuilder sb = new StringBuilder();
      for (String key : jsonDiff.getData().keySet()) {
         Object value = jsonDiff.getData().get(key);

         if (key.startsWith(JsonDiff.ADDED_ITEM_CODE)) {
            sb.append(prefixStr + "+[" + JsonDiff.getStringWithoutCode(key)
                  + "]\n");
            sb.append(print(prefixStr + "  ", value));
         }
         else if (key.startsWith(JsonDiff.REMOVED_ITEM_CODE)) {
            sb.append(prefixStr + "-[" + JsonDiff.getStringWithoutCode(key)
                  + "]\n");
            sb.append(print(prefixStr + "  ", value));
         }
         else if (key.startsWith(JsonDiff.COMMON_ITEM_CODE)) {
            sb.append(prefixStr + "~[" + JsonDiff.getStringWithoutCode(key)
                  + "]\n");
            sb.append(print(prefixStr + "  ", value));
         }
         else if (key.startsWith(JsonDiff.CHANGED_ITEM_CODE)) {
            sb.append(prefixStr + "~[" + JsonDiff.getStringWithoutCode(key)
                  + "]\n");
            TreeMap<?, ?> treeMap = (TreeMap<?, ?>) value;

            Object baseValue = treeMap.get(JsonDiff.CHANGED_ITEM_BASE);
            Object deltaValue = treeMap.get(JsonDiff.CHANGED_ITEM_DELTA);

            sb.append(prefixStr + "BASE\n");
            sb.append(print(prefixStr + " ", baseValue));

            sb.append(prefixStr + "DELTA\n");
            sb.append(print(prefixStr + " ", deltaValue));
         }
         else {
            sb.append(prefixStr + key + "\n");
            sb.append(print(prefixStr + "  ", value));
         }
      }
      return sb.toString();
   }

   private static String print(String prefixStr, LinkedList<?> list) {
      final StringBuilder sb = new StringBuilder();
      for (Object obj : list) {
         sb.append(print(prefixStr, obj));
      }
      return sb.toString();
   }

   private static String print(String prefixStr, Object value) {
      final StringBuilder sb = new StringBuilder();
      if (value instanceof JsonDiff) {
         sb.append(((JsonDiff) value).prettyPrint(prefixStr + "  "));
      }
      else if (value instanceof TreeMap<?, ?>) {
         sb.append(print(prefixStr + "  ", (TreeMap<?, ?>) value));
      }
      else if (value instanceof LinkedList<?>) {
         sb.append(print(prefixStr + "  ", (LinkedList<?>) value));
      }
      else if (value instanceof String) {
         sb.append(prefixStr + "  " + (String) value + "\n");
      }
      else {
         ObjectMapper mapper = new BatfishObjectMapper();
         try {
            sb.append(mapper.writeValueAsString(value));
         }
         catch (JsonProcessingException e) {
            sb.append("Exception while pretty printing " + value.toString()
                  + "\n" + e.getMessage());
         }
      }
      return sb.toString();
   }

   private static String print(String prefixStr, TreeMap<?, ?> treeMap) {
      final StringBuilder sb = new StringBuilder();
      for (Object keyObject : treeMap.keySet()) {
         String key = (String) keyObject;
         Object value = treeMap.get(key);

         sb.append(prefixStr + key + "\n");
         sb.append(print(prefixStr + "  ", value));
      }
      return sb.toString();
   }
}