diff --git a/solr/core/src/java/org/apache/solr/servlet/ZookeeperInfoServlet.java b/solr/core/src/java/org/apache/solr/servlet/ZookeeperInfoServlet.java
index c736580d852..008ec76727e 100644
--- a/solr/core/src/java/org/apache/solr/servlet/ZookeeperInfoServlet.java
+++ b/solr/core/src/java/org/apache/solr/servlet/ZookeeperInfoServlet.java
@@ -17,6 +17,21 @@
 
 package org.apache.solr.servlet;
 
+import org.apache.noggit.CharArr;
+import org.apache.noggit.JSONWriter;
+import org.apache.solr.cloud.ZkController;
+import org.apache.solr.common.cloud.SolrZkClient;
+import org.apache.solr.common.util.StrUtils;
+import org.apache.solr.core.CoreContainer;
+import org.apache.zookeeper.KeeperException;
+import org.apache.zookeeper.data.Stat;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.UnsupportedEncodingException;
@@ -25,19 +40,6 @@ import java.util.Date;
 import java.util.List;
 import java.util.concurrent.TimeoutException;
 
-import javax.servlet.ServletException;
-import javax.servlet.http.HttpServlet;
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-
-import org.apache.solr.cloud.ZkController;
-import org.apache.solr.common.cloud.SolrZkClient;
-import org.apache.solr.common.util.StrUtils;
-import org.apache.solr.common.util.XML;
-import org.apache.solr.core.CoreContainer;
-import org.apache.zookeeper.KeeperException;
-import org.apache.zookeeper.data.Stat;
-
 
 /**
  * Zookeeper Info
@@ -45,6 +47,7 @@ import org.apache.zookeeper.data.Stat;
  * @since solr 4.0
  */
 public final class ZookeeperInfoServlet extends HttpServlet {
+  static final Logger log = LoggerFactory.getLogger(ZookeeperInfoServlet.class);
 
   @Override
   public void init() throws ServletException {
@@ -53,27 +56,28 @@ public final class ZookeeperInfoServlet extends HttpServlet {
   @Override
   public void doGet(HttpServletRequest request,
                     HttpServletResponse response)
-          throws IOException, ServletException {
+      throws IOException, ServletException {
     response.setCharacterEncoding("UTF-8");
     response.setContentType("application/json");
 
+    // This attribute is set by the SolrDispatchFilter
     CoreContainer cores = (CoreContainer) request.getAttribute("org.apache.solr.CoreContainer");
-    
+
     String path = request.getParameter("path");
     String addr = request.getParameter("addr");
-    
-    if (addr != null && addr.length() == 0)
-    {
+
+    if (addr != null && addr.length() == 0) {
       addr = null;
     }
-    
+
     String detailS = request.getParameter("detail");
     boolean detail = detailS != null && detailS.equals("true");
     PrintWriter out = response.getWriter();
-    
+
+
     ZKPrinter printer = new ZKPrinter(response, out, cores.getZkController(), addr);
     printer.detail = detail;
-    
+
     try {
       printer.print(path);
     } finally {
@@ -84,455 +88,350 @@ public final class ZookeeperInfoServlet extends HttpServlet {
   @Override
   public void doPost(HttpServletRequest request,
                      HttpServletResponse response)
-          throws IOException, ServletException {
-    doGet(request,response);
+      throws IOException, ServletException {
+    doGet(request, response);
   }
 
 
   //--------------------------------------------------------------------------------------
-  // 
+  //
   //--------------------------------------------------------------------------------------
-  
-  static class ZKPrinter
-  {
-  
+
+  static class ZKPrinter {
     static boolean FULLPATH_DEFAULT = false;
-  
+
     boolean indent = true;
     boolean fullpath = FULLPATH_DEFAULT;
     boolean detail = false;
-  
+
     String addr; // the address passed to us
     String keeperAddr; // the address we're connected to
-  
+
     boolean doClose;  // close the client after done if we opened it
-  
-    HttpServletResponse response;
-    PrintWriter out;
+
+    final HttpServletResponse response;
+    final PrintWriter out;
     SolrZkClient zkClient;
-  
+
     int level;
     int maxData = 95;
-  
-    public ZKPrinter(HttpServletResponse response, PrintWriter out, ZkController controller, String addr) throws IOException
-    {
+
+    public ZKPrinter(HttpServletResponse response, PrintWriter out, ZkController controller, String addr) throws IOException {
       this.response = response;
       this.out = out;
       this.addr = addr;
-      
-      if (addr == null)
-      {
-        if (controller != null)
-        {
+
+      if (addr == null) {
+        if (controller != null) {
           // this core is zk enabled
           keeperAddr = controller.getZkServerAddress();
           zkClient = controller.getZkClient();
-          if (zkClient != null && zkClient.isConnected())
-          {
+          if (zkClient != null && zkClient.isConnected()) {
             return;
-          }
-          else
-          {
+          } else {
             // try a different client with this address
             addr = keeperAddr;
           }
         }
       }
-  
+
       keeperAddr = addr;
-      if (addr == null)
-      {
-        response.setStatus(404);
-        out.println
-        (
-          "{" +
-          "\"status\": 404" +
-          ", \"error\" : \"Zookeeper is not configured for this Solr Core. Please try connecting to an alternate zookeeper address.\"" +
-          "}"
-        );
+      if (addr == null) {
+        writeError(404, "Zookeeper is not configured for this Solr Core. Please try connecting to an alternate zookeeper address.");
         return;
       }
-  
-      try
-      {
+
+      try {
         zkClient = new SolrZkClient(addr, 10000);
         doClose = true;
-      }
-      catch (TimeoutException e)
-      {
-        response.setStatus(503);
-        out.println
-        (
-          "{" +
-          "\"status\": 503" +
-          ", \"error\" : \"Could not connect to zookeeper at '" + addr + "'\"" +
-          "}"
-        );
+      } catch (TimeoutException e) {
+        writeError(503, "Could not connect to zookeeper at '" + addr + "'\"");
         zkClient = null;
         return;
-      }
-      catch (InterruptedException e)
-      {
+      } catch (InterruptedException e) {
         // Restore the interrupted status
         Thread.currentThread().interrupt();
-        response.setStatus(503);
-        out.println
-        (
-          "{" +
-          "\"status\": 503" +
-          ", \"error\" : \"Could not connect to zookeeper at '" + addr + "'\"" +
-          "}"
-        );
+        writeError(503, "Could not connect to zookeeper at '" + addr + "'\"");
         zkClient = null;
         return;
       }
-  
+
     }
 
-    public void close()
-    {
+    public void close() {
       try {
-        if (doClose)
-        {
+        if (doClose) {
           zkClient.close();
         }
       } catch (InterruptedException e) {
-          // ignore exception on close
+        // ignore exception on close
       }
     }
-  
+
     // main entry point
-    void print(String path) throws IOException
-    {
+    void print(String path) throws IOException {
       if (zkClient == null) {
         return;
       }
-  
+
       // normalize path
       if (path == null) {
         path = "/";
-      }
-      else {
+      } else {
         path.trim();
-        if (path.length() == 0)
-        {
+        if (path.length() == 0) {
           path = "/";
         }
       }
-      
-      if (path.endsWith("/") && path.length() > 1)
-      {
+
+      if (path.endsWith("/") && path.length() > 1) {
         path = path.substring(0, path.length() - 1);
       }
-  
+
       int idx = path.lastIndexOf('/');
       String parent = idx >= 0 ? path.substring(0, idx) : path;
-      if (parent.length() == 0)
-      {
+      if (parent.length() == 0) {
         parent = "/";
       }
-  
-      out.println("{");
-  
-      if (detail)
-      {
-        printZnode(path);
-        out.println(", ");
-      }
-  
-      out.println("\"tree\" : [");
-      printTree(path);
-      out.println("]");
-  
-      out.println("}");
-    }
-  
-    void exception(Exception e)
-    {
-      response.setStatus(500);
-      out.println
-      (
-        "{" +
-        "\"status\": 500" +
-        ", \"error\" : \"" + e.toString() + "\"" +
-        "}"
-      );
-    }
-  
-    void xmlescape(String s)
-    {
-      try
-      {
-        XML.escapeCharData(s, out);
-      }
-      catch (IOException e)
-      {
-        throw new RuntimeException(e);
-      }
-    }
-  
-    // collapse all whitespace to a single space or escaped newline
-    String compress(String str) {
-      StringBuilder sb = new StringBuilder();
-      for (int i = 0; i < str.length(); i++) {
-        char ch = str.charAt(i);
-        boolean whitespace = false;
-        boolean newline = false;
-        while (Character.isWhitespace(ch)) {
-          whitespace = true;
-          if (ch == '\n')
-            newline = true;
-          if (++i >= str.length())
-            return sb.toString();
-          ch = str.charAt(i);
+
+      CharArr chars = new CharArr();
+      JSONWriter json = new JSONWriter(chars, 2);
+      json.startObject();
+
+      if (detail) {
+        if (!printZnode(json, path)) {
+          return;
         }
-
-        if (newline) {
-          // sb.append("\\n");
-          sb.append("  ");  // collapse newline to two spaces
-        } else if (whitespace) {
-          sb.append(' ');
-        }
-
-        // TODO: handle non-printable chars
-        sb.append(ch);
-
-        if (sb.length() >= maxData)
-          return sb.toString() + " ...";
+        json.writeValueSeparator();
       }
-      return sb.toString();
+
+      json.writeString("tree");
+      json.writeNameSeparator();
+      json.startArray();
+      if (!printTree(json, path)) {
+        return; // there was an error
+      }
+      json.endArray();
+      json.endObject();
+      out.println(chars.toString());
     }
 
-    void url(String label, String path, boolean detail) throws IOException {
-      try {
-        out.print("<a href=\"zookeeper?");
-        if (path != null) {
-          out.print("path=");
-          out.print(URLEncoder.encode(path, "UTF-8"));
-        }
-        if (detail) {
-          out.print("&detail=" + detail);
-        }
-        if (fullpath != FULLPATH_DEFAULT) {
-          out.print("&fullpath=" + fullpath);
-        }
-        if (addr != null) {
-          out.print("&addr=");
-          out.print(URLEncoder.encode(addr, "UTF-8"));
-        }
+    void writeError(int code, String msg) {
+      response.setStatus(code);
 
-        out.print("\">");
-        xmlescape(label);
-        out.print("</a>");
+      CharArr chars = new CharArr();
+      JSONWriter w = new JSONWriter(chars, 2);
+      w.startObject();
+      w.indent();
+      w.writeString("status");
+      w.writeNameSeparator();
+      w.write(code);
+      w.writeValueSeparator();
+      w.indent();
+      w.writeString("error");
+      w.writeNameSeparator();
+      w.writeString(msg);
+      w.endObject();
 
-      } catch (UnsupportedEncodingException e) {
-        exception(e);
-      }
+      out.println(chars.toString());
     }
 
-    void printTree(String path) throws IOException
-    {
+
+    boolean printTree(JSONWriter json, String path) throws IOException {
       String label = path;
-      if (!fullpath)
-      {
+      if (!fullpath) {
         int idx = path.lastIndexOf('/');
         label = idx > 0 ? path.substring(idx + 1) : path;
       }
-  
-      //url(label, path, true);
-      out.println("{");
-      out.println("\"data\" : \"" + label + "\"");
-  
+      json.startObject();
+      //writeKeyValue(json, "data", label, true );
+      json.writeString("data");
+      json.writeNameSeparator();
+
+      json.startObject();
+      writeKeyValue(json, "title", label, true);
+      json.writeValueSeparator();
+      json.writeString("attr");
+      json.writeNameSeparator();
+      json.startObject();
+      writeKeyValue(json, "href", "zookeeper?detail=true&path=" + URLEncoder.encode(path, "UTF-8"), true);
+      json.endObject();
+      json.endObject();
+
       Stat stat = new Stat();
-      try
-      {
+      try {
         byte[] data = zkClient.getData(path, null, stat, true);
-  
-        if( stat.getEphemeralOwner() != 0 )
-        {
-          out.println(", \"ephemeral\" : true");
-          out.println(", \"version\" : \"" + stat.getVersion() + "\"");
+
+        if (stat.getEphemeralOwner() != 0) {
+          writeKeyValue(json, "ephemeral", true, false);
+          writeKeyValue(json, "version", stat.getVersion(), false);
         }
-        
+
         /*
         if (stat.getNumChildren() != 0)
         {
+          writeKeyValue(json, "children_count",  stat.getNumChildren(), false );
           out.println(", \"children_count\" : \"" + stat.getNumChildren() + "\"");
         }
         */
-  
+
         //if (data != null)
-        if( stat.getDataLength() != 0 )
-        {
+        if (stat.getDataLength() != 0) {
           String str;
-          try
-          {
+          try {
             str = new String(data, "UTF-8");
             str = str.replaceAll("\\\"", "\\\\\"");
-  
-            out.print(", \"content\" : \"");
-            //xmlescape(compress(str));
-            out.print(compress(str));
-            out.println("\"");
-          }
-          catch (UnsupportedEncodingException e)
-          {
+
+            //writeKeyValue(json, "content", str, false );
+          } catch (UnsupportedEncodingException e) {
             // not UTF8
             StringBuilder sb = new StringBuilder("BIN(");
             sb.append("len=" + data.length);
             sb.append("hex=");
             int limit = Math.min(data.length, maxData / 2);
-            for (int i = 0; i < limit; i++)
-            {
+            for (int i = 0; i < limit; i++) {
               byte b = data[i];
               sb.append(StrUtils.HEX_DIGITS[(b >> 4) & 0xf]);
               sb.append(StrUtils.HEX_DIGITS[b & 0xf]);
             }
-            if (limit != data.length)
-            {
+            if (limit != data.length) {
               sb.append("...");
             }
             sb.append(")");
             str = sb.toString();
-            //out.print(str);
+            //?? writeKeyValue(json, "content", str, false );
           }
         }
-      }
-      catch (IllegalArgumentException e)
-      {
+      } catch (IllegalArgumentException e) {
         // path doesn't exist (must have been removed)
-        out.println("(path gone)");
+        writeKeyValue(json, "warning", "(path gone)", false);
+      } catch (KeeperException e) {
+        writeKeyValue(json, "warning", e.toString(), false);
+        log.warn("Keeper Exception", e);
+      } catch (InterruptedException e) {
+        writeKeyValue(json, "warning", e.toString(), false);
+        log.warn("InterruptedException", e);
       }
-      catch (KeeperException e)
-      {
-        e.printStackTrace();
-      }
-      catch (InterruptedException e)
-      {
-        e.printStackTrace();
-      }
-  
-      if( stat.getNumChildren() > 0 )
-      {
-        out.print(", \"children\" : [");
-  
-        List<String> children = null;
-        try
-        {
-          children = zkClient.getChildren(path, null, true);
+
+      if (stat.getNumChildren() > 0) {
+        json.writeValueSeparator();
+        if (indent) {
+          json.indent();
         }
-        catch (KeeperException e)
-        {
-          exception(e);
-          return;
-        }
-        catch (InterruptedException e)
-        {
-          exception(e);
-        }
-        catch (IllegalArgumentException e)
-        {
-          // path doesn't exist (must have been removed)
-          out.println("(children gone)");
-        }
-  
-        Integer i = 0;
-        for( String child : children )
-        {
-          if( 0 != i )
-          {
-            out.print(", ");
+        json.writeString("children");
+        json.writeNameSeparator();
+        json.startArray();
+
+        try {
+          List<String> children = zkClient.getChildren(path, null, true);
+          java.util.Collections.sort(children);
+
+          boolean first = true;
+          for (String child : children) {
+            if (!first) {
+              json.writeValueSeparator();
+            }
+
+            String childPath = path + (path.endsWith("/") ? "" : "/") + child;
+            if (!printTree(json, childPath)) {
+              return false;
+            }
+            first = false;
           }
-  
-          String childPath = path + (path.endsWith("/") ? "" : "/") + child;
-          printTree( childPath );
-  
-          i++;
+        } catch (KeeperException e) {
+          writeError(500, e.toString());
+          return false;
+        } catch (InterruptedException e) {
+          writeError(500, e.toString());
+          return false;
+        } catch (IllegalArgumentException e) {
+          // path doesn't exist (must have been removed)
+          json.writeString("(children gone)");
         }
-  
-        out.println("]");
+
+        json.endArray();
       }
-  
-      out.println("}");
+
+      json.endObject();
+      return true;
     }
 
     String time(long ms) {
       return (new Date(ms)).toString() + " (" + ms + ")";
     }
-  
-    void printZnode(String path) throws IOException
-    {
-      try
-      {
+
+    public void writeKeyValue(JSONWriter json, String k, Object v, boolean isFirst) {
+      if (!isFirst) {
+        json.writeValueSeparator();
+      }
+      if (indent) {
+        json.indent();
+      }
+      json.writeString(k);
+      json.writeNameSeparator();
+      json.write(v);
+    }
+
+    boolean printZnode(JSONWriter json, String path) throws IOException {
+      try {
         Stat stat = new Stat();
         byte[] data = zkClient.getData(path, null, stat, true);
-  
-        out.println("\"znode\" : {");
-  
-        out.print("\"path\" : \"");
-        xmlescape(path);
-        out.println("\"");
-  
-        out.println(", \"version\" : \"" + stat.getVersion() + "\"");
-        out.println(", \"aversion\" : \"" + stat.getAversion() + "\"");
-        out.println(", \"cversion\" : \"" + stat.getCversion() + "\"");
-        out.println(", \"ctime\" : \"" + time(stat.getCtime()) + "\"");
-        out.println(", \"mtime\" : \"" + time(stat.getMtime()) + "\"");
-        out.println(", \"czxid\" : \"" + stat.getCzxid() + "\"");
-        out.println(", \"mzxid\" : \"" + stat.getMzxid() + "\"");
-        out.println(", \"pzxid\" : \"" + stat.getPzxid() + "\"");
-        out.println(", \"children_count\" : \"" + stat.getNumChildren() + "\"");
-        out.println(", \"ephemeralOwner\" : \"" + stat.getEphemeralOwner() + "\"");
-        out.println(", \"dataLength\" : \"" + stat.getDataLength() + "\"");
-  
-        if( stat.getDataLength() != 0 )
-        {
-          boolean isBinary = false;
+
+        json.writeString("znode");
+        json.writeNameSeparator();
+        json.startObject();
+
+        writeKeyValue(json, "path", path, true);
+
+        json.writeValueSeparator();
+        json.writeString("prop");
+        json.writeNameSeparator();
+        json.startObject();
+        writeKeyValue(json, "version", stat.getVersion(), true);
+        writeKeyValue(json, "aversion", stat.getAversion(), false);
+        writeKeyValue(json, "children_count", stat.getNumChildren(), false);
+        writeKeyValue(json, "ctime", time(stat.getCtime()), false);
+        writeKeyValue(json, "cversion", stat.getCversion(), false);
+        writeKeyValue(json, "czxid", stat.getCzxid(), false);
+        writeKeyValue(json, "dataLength", stat.getDataLength(), false);
+        writeKeyValue(json, "ephemeralOwner", stat.getEphemeralOwner(), false);
+        writeKeyValue(json, "mtime", time(stat.getMtime()), false);
+        writeKeyValue(json, "mzxid", stat.getMzxid(), false);
+        writeKeyValue(json, "pzxid", stat.getPzxid(), false);
+        json.endObject();
+
+        if (stat.getDataLength() != 0) {
           String str;
-          try
-          {
+          try {
             str = new String(data, "UTF-8");
-          }
-          catch (UnsupportedEncodingException e)
-          {
+          } catch (UnsupportedEncodingException e) {
             // The results are unspecified
             // when the bytes are not properly encoded.
-  
+
             // not UTF8
             StringBuilder sb = new StringBuilder(data.length * 2);
-            for (int i = 0; i < data.length; i++)
-            {
+            for (int i = 0; i < data.length; i++) {
               byte b = data[i];
               sb.append(StrUtils.HEX_DIGITS[(b >> 4) & 0xf]);
               sb.append(StrUtils.HEX_DIGITS[b & 0xf]);
-              if ((i & 0x3f) == 0x3f)
-              {
+              if ((i & 0x3f) == 0x3f) {
                 sb.append("\n");
               }
             }
             str = sb.toString();
           }
           str = str.replaceAll("\\\"", "\\\\\"");
-  
-          out.print(", \"data\" : \"");
-          //xmlescape(str);
-          out.print(str);
-          out.println("\"");
+          writeKeyValue(json, "data", str, false);
         }
-  
-        out.println("}");
-  
-      }
-      catch (KeeperException e)
-      {
-        exception(e);
-        return;
-      }
-      catch (InterruptedException e)
-      {
-        exception(e);
+        json.endObject();
+      } catch (KeeperException e) {
+        writeError(500, e.toString());
+        return false;
+      } catch (InterruptedException e) {
+        writeError(500, e.toString());
+        return false;
       }
+      return true;
     }
   }
 }
-