static void generateDirectoryStructure(
      JspWriter out, HttpServletRequest req, HttpServletResponse resp, Configuration conf)
      throws IOException, InterruptedException {
    final String dir =
        JspHelper.validatePath(StringEscapeUtils.unescapeHtml(req.getParameter("dir")));
    if (dir == null) {
      out.print("Invalid input");
      return;
    }
    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
    UserGroupInformation ugi = JspHelper.getUGI(req, conf);
    String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
    int namenodeInfoPort = -1;
    if (namenodeInfoPortStr != null) namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);
    final String nnAddr = req.getParameter(JspHelper.NAMENODE_ADDRESS);
    if (nnAddr == null) {
      out.print(JspHelper.NAMENODE_ADDRESS + " url param is null");
      return;
    }

    DFSClient dfs = getDFSClient(ugi, nnAddr, conf);
    String target = dir;
    final HdfsFileStatus targetStatus = dfs.getFileInfo(target);
    if (targetStatus == null) { // not exists
      out.print("<h3>File or directory : " + target + " does not exist</h3>");
      JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, target, nnAddr);
    } else {
      if (!targetStatus.isDir()) { // a file
        List<LocatedBlock> blocks =
            dfs.getNamenode().getBlockLocations(dir, 0, 1).getLocatedBlocks();

        LocatedBlock firstBlock = null;
        DatanodeInfo[] locations = null;
        if (blocks.size() > 0) {
          firstBlock = blocks.get(0);
          locations = firstBlock.getLocations();
        }
        if (locations == null || locations.length == 0) {
          out.print("Empty file");
        } else {
          DatanodeInfo chosenNode = JspHelper.bestNode(firstBlock, conf);
          String fqdn = canonicalize(chosenNode.getIpAddr());
          int datanodePort = chosenNode.getXferPort();
          String redirectLocation =
              "http://"
                  + fqdn
                  + ":"
                  + chosenNode.getInfoPort()
                  + "/browseBlock.jsp?blockId="
                  + firstBlock.getBlock().getBlockId()
                  + "&blockSize="
                  + firstBlock.getBlock().getNumBytes()
                  + "&genstamp="
                  + firstBlock.getBlock().getGenerationStamp()
                  + "&filename="
                  + URLEncoder.encode(dir, "UTF-8")
                  + "&datanodePort="
                  + datanodePort
                  + "&namenodeInfoPort="
                  + namenodeInfoPort
                  + JspHelper.getDelegationTokenUrlParam(tokenString)
                  + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr);
          resp.sendRedirect(redirectLocation);
        }
        return;
      }
      // directory
      // generate a table and dump the info
      String[] headings = {
        "Name",
        "Type",
        "Size",
        "Replication",
        "Block Size",
        "Modification Time",
        "Permission",
        "Owner",
        "Group"
      };
      out.print("<h3>Contents of directory ");
      JspHelper.printPathWithLinks(dir, out, namenodeInfoPort, tokenString, nnAddr);
      out.print("</h3><hr>");
      JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, dir, nnAddr);
      out.print("<hr>");

      File f = new File(dir);
      String parent;
      if ((parent = f.getParent()) != null)
        out.print(
            "<a href=\""
                + req.getRequestURL()
                + "?dir="
                + parent
                + "&namenodeInfoPort="
                + namenodeInfoPort
                + JspHelper.getDelegationTokenUrlParam(tokenString)
                + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr)
                + "\">Go to parent directory</a><br>");

      DirectoryListing thisListing = dfs.listPaths(target, HdfsFileStatus.EMPTY_NAME);
      if (thisListing == null || thisListing.getPartialListing().length == 0) {
        out.print("Empty directory");
      } else {
        JspHelper.addTableHeader(out);
        int row = 0;
        JspHelper.addTableRow(out, headings, row++);
        String cols[] = new String[headings.length];
        do {
          HdfsFileStatus[] files = thisListing.getPartialListing();
          for (int i = 0; i < files.length; i++) {
            String localFileName = files[i].getLocalName();
            // Get the location of the first block of the file
            if (!files[i].isDir()) {
              cols[1] = "file";
              cols[2] = StringUtils.byteDesc(files[i].getLen());
              cols[3] = Short.toString(files[i].getReplication());
              cols[4] = StringUtils.byteDesc(files[i].getBlockSize());
            } else {
              cols[1] = "dir";
              cols[2] = "";
              cols[3] = "";
              cols[4] = "";
            }
            String datanodeUrl =
                req.getRequestURL()
                    + "?dir="
                    + URLEncoder.encode(files[i].getFullName(target), "UTF-8")
                    + "&namenodeInfoPort="
                    + namenodeInfoPort
                    + JspHelper.getDelegationTokenUrlParam(tokenString)
                    + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr);
            cols[0] = "<a href=\"" + datanodeUrl + "\">" + localFileName + "</a>";
            cols[5] = lsDateFormat.format(new Date((files[i].getModificationTime())));
            cols[6] = files[i].getPermission().toString();
            cols[7] = files[i].getOwner();
            cols[8] = files[i].getGroup();
            JspHelper.addTableRow(out, cols, row++);
          }
          if (!thisListing.hasMore()) {
            break;
          }
          thisListing = dfs.listPaths(target, thisListing.getLastName());
        } while (thisListing != null);
        JspHelper.addTableFooter(out);
      }
    }
    out.print(
        "<br><a href=\"http://"
            + canonicalize(nnAddr)
            + ":"
            + namenodeInfoPort
            + "/dfshealth.jsp\">Go back to DFS home</a>");
    dfs.close();
  }
  static void generateFileChunks(JspWriter out, HttpServletRequest req, Configuration conf)
      throws IOException, InterruptedException {
    long startOffset = 0;
    int datanodePort = 0;

    final String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
    final String nnAddr = req.getParameter(JspHelper.NAMENODE_ADDRESS);
    if (nnAddr == null) {
      out.print(JspHelper.NAMENODE_ADDRESS + " url param is null");
      return;
    }
    final String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
    UserGroupInformation ugi = JspHelper.getUGI(req, conf);
    int namenodeInfoPort = -1;
    if (namenodeInfoPortStr != null) namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);

    final String filename =
        JspHelper.validatePath(StringEscapeUtils.unescapeHtml(req.getParameter("filename")));
    if (filename == null) {
      out.print("Invalid input (filename absent)");
      return;
    }

    final Long blockId = JspHelper.validateLong(req.getParameter("blockId"));
    if (blockId == null) {
      out.print("Invalid input (blockId absent)");
      return;
    }

    final DFSClient dfs = getDFSClient(ugi, nnAddr, conf);

    String bpid = null;
    Token<BlockTokenIdentifier> blockToken = BlockTokenSecretManager.DUMMY_TOKEN;
    List<LocatedBlock> blks =
        dfs.getNamenode().getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
    if (blks == null || blks.size() == 0) {
      out.print("Can't locate file blocks");
      dfs.close();
      return;
    }

    boolean needBlockToken =
        conf.getBoolean(
            DFSConfigKeys.DFS_BLOCK_ACCESS_TOKEN_ENABLE_KEY,
            DFSConfigKeys.DFS_BLOCK_ACCESS_TOKEN_ENABLE_DEFAULT);

    for (int i = 0; i < blks.size(); i++) {
      if (blks.get(i).getBlock().getBlockId() == blockId) {
        bpid = blks.get(i).getBlock().getBlockPoolId();
        if (needBlockToken) {
          blockToken = blks.get(i).getBlockToken();
        }
        break;
      }
    }

    final Long genStamp = JspHelper.validateLong(req.getParameter("genstamp"));
    if (genStamp == null) {
      out.print("Invalid input (genstamp absent)");
      return;
    }

    long blockSize = 0;
    final String blockSizeStr = req.getParameter("blockSize");
    if (blockSizeStr == null) {
      out.print("Invalid input (blockSize absent)");
      return;
    }
    blockSize = Long.parseLong(blockSizeStr);

    final int chunkSizeToView =
        JspHelper.string2ChunkSizeToView(
            req.getParameter("chunkSizeToView"), getDefaultChunkSize(conf));

    String startOffsetStr = req.getParameter("startOffset");
    if (startOffsetStr == null || Long.parseLong(startOffsetStr) < 0) startOffset = 0;
    else startOffset = Long.parseLong(startOffsetStr);

    String datanodePortStr = req.getParameter("datanodePort");
    if (datanodePortStr == null) {
      out.print("Invalid input (datanodePort absent)");
      return;
    }
    datanodePort = Integer.parseInt(datanodePortStr);
    out.print("<h3>File: ");
    JspHelper.printPathWithLinks(filename, out, namenodeInfoPort, tokenString, nnAddr);
    out.print("</h3><hr>");
    String parent = new File(filename).getParent();
    JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, parent, nnAddr);
    out.print("<hr>");
    out.print(
        "<a href=\"http://"
            + req.getServerName()
            + ":"
            + req.getServerPort()
            + "/browseDirectory.jsp?dir="
            + URLEncoder.encode(parent, "UTF-8")
            + "&namenodeInfoPort="
            + namenodeInfoPort
            + JspHelper.getDelegationTokenUrlParam(tokenString)
            + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr)
            + "\"><i>Go back to dir listing</i></a><br>");
    out.print("<a href=\"#viewOptions\">Advanced view/download options</a><br>");
    out.print("<hr>");

    // Determine the prev & next blocks
    long nextStartOffset = 0;
    long nextBlockSize = 0;
    String nextBlockIdStr = null;
    String nextGenStamp = null;
    String nextHost = req.getServerName();
    int nextPort = req.getServerPort();
    int nextDatanodePort = datanodePort;
    // determine data for the next link
    if (startOffset + chunkSizeToView >= blockSize) {
      // we have to go to the next block from this point onwards
      List<LocatedBlock> blocks =
          dfs.getNamenode().getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
      for (int i = 0; i < blocks.size(); i++) {
        if (blocks.get(i).getBlock().getBlockId() == blockId) {
          if (i != blocks.size() - 1) {
            LocatedBlock nextBlock = blocks.get(i + 1);
            nextBlockIdStr = Long.toString(nextBlock.getBlock().getBlockId());
            nextGenStamp = Long.toString(nextBlock.getBlock().getGenerationStamp());
            nextStartOffset = 0;
            nextBlockSize = nextBlock.getBlock().getNumBytes();
            DatanodeInfo d = JspHelper.bestNode(nextBlock, conf);
            nextDatanodePort = d.getXferPort();
            nextHost = d.getIpAddr();
            nextPort = d.getInfoPort();
          }
        }
      }
    } else {
      // we are in the same block
      nextBlockIdStr = blockId.toString();
      nextStartOffset = startOffset + chunkSizeToView;
      nextBlockSize = blockSize;
      nextGenStamp = genStamp.toString();
    }
    String nextUrl = null;
    if (nextBlockIdStr != null) {
      nextUrl =
          "http://"
              + canonicalize(nextHost)
              + ":"
              + nextPort
              + "/browseBlock.jsp?blockId="
              + nextBlockIdStr
              + "&blockSize="
              + nextBlockSize
              + "&startOffset="
              + nextStartOffset
              + "&genstamp="
              + nextGenStamp
              + "&filename="
              + URLEncoder.encode(filename, "UTF-8")
              + "&chunkSizeToView="
              + chunkSizeToView
              + "&datanodePort="
              + nextDatanodePort
              + "&namenodeInfoPort="
              + namenodeInfoPort
              + JspHelper.getDelegationTokenUrlParam(tokenString)
              + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr);
      out.print("<a href=\"" + nextUrl + "\">View Next chunk</a>&nbsp;&nbsp;");
    }
    // determine data for the prev link
    String prevBlockIdStr = null;
    String prevGenStamp = null;
    long prevStartOffset = 0;
    long prevBlockSize = 0;
    String prevHost = req.getServerName();
    int prevPort = req.getServerPort();
    int prevDatanodePort = datanodePort;
    if (startOffset == 0) {
      List<LocatedBlock> blocks =
          dfs.getNamenode().getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
      for (int i = 0; i < blocks.size(); i++) {
        if (blocks.get(i).getBlock().getBlockId() == blockId) {
          if (i != 0) {
            LocatedBlock prevBlock = blocks.get(i - 1);
            prevBlockIdStr = Long.toString(prevBlock.getBlock().getBlockId());
            prevGenStamp = Long.toString(prevBlock.getBlock().getGenerationStamp());
            prevStartOffset = prevBlock.getBlock().getNumBytes() - chunkSizeToView;
            if (prevStartOffset < 0) prevStartOffset = 0;
            prevBlockSize = prevBlock.getBlock().getNumBytes();
            DatanodeInfo d = JspHelper.bestNode(prevBlock, conf);
            prevDatanodePort = d.getXferPort();
            prevHost = d.getIpAddr();
            prevPort = d.getInfoPort();
          }
        }
      }
    } else {
      // we are in the same block
      prevBlockIdStr = blockId.toString();
      prevStartOffset = startOffset - chunkSizeToView;
      if (prevStartOffset < 0) prevStartOffset = 0;
      prevBlockSize = blockSize;
      prevGenStamp = genStamp.toString();
    }

    String prevUrl = null;
    if (prevBlockIdStr != null) {
      prevUrl =
          "http://"
              + canonicalize(prevHost)
              + ":"
              + prevPort
              + "/browseBlock.jsp?blockId="
              + prevBlockIdStr
              + "&blockSize="
              + prevBlockSize
              + "&startOffset="
              + prevStartOffset
              + "&filename="
              + URLEncoder.encode(filename, "UTF-8")
              + "&chunkSizeToView="
              + chunkSizeToView
              + "&genstamp="
              + prevGenStamp
              + "&datanodePort="
              + prevDatanodePort
              + "&namenodeInfoPort="
              + namenodeInfoPort
              + JspHelper.getDelegationTokenUrlParam(tokenString)
              + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr);
      out.print("<a href=\"" + prevUrl + "\">View Prev chunk</a>&nbsp;&nbsp;");
    }
    out.print("<hr>");
    out.print("<textarea cols=\"100\" rows=\"25\" wrap=\"virtual\" style=\"width:100%\" READONLY>");
    try {
      JspHelper.streamBlockInAscii(
          new InetSocketAddress(req.getServerName(), datanodePort),
          bpid,
          blockId,
          blockToken,
          genStamp,
          blockSize,
          startOffset,
          chunkSizeToView,
          out,
          conf);
    } catch (Exception e) {
      out.print(e);
    }
    out.print("</textarea>");
    dfs.close();
  }
  static void generateFileChunksForTail(JspWriter out, HttpServletRequest req, Configuration conf)
      throws IOException, InterruptedException {
    String referrer = null;
    boolean noLink = false;
    try {
      referrer = new URL(req.getParameter("referrer")).toString();
    } catch (IOException e) {
      referrer = null;
      noLink = true;
    }

    final String filename =
        JspHelper.validatePath(StringEscapeUtils.unescapeHtml(req.getParameter("filename")));
    if (filename == null) {
      out.print("Invalid input (file name absent)");
      return;
    }
    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
    UserGroupInformation ugi = JspHelper.getUGI(req, conf);

    String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
    String nnAddr = req.getParameter(JspHelper.NAMENODE_ADDRESS);
    int namenodeInfoPort = -1;
    if (namenodeInfoPortStr != null) namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);

    final int chunkSizeToView =
        JspHelper.string2ChunkSizeToView(
            req.getParameter("chunkSizeToView"), getDefaultChunkSize(conf));

    if (!noLink) {
      out.print("<h3>Tail of File: ");
      JspHelper.printPathWithLinks(filename, out, namenodeInfoPort, tokenString, nnAddr);
      out.print("</h3><hr>");
      out.print("<a href=\"" + referrer + "\">Go Back to File View</a><hr>");
    } else {
      out.print("<h3>" + filename + "</h3>");
    }
    out.print("<b>Chunk size to view (in bytes, up to file's DFS block size): </b>");
    out.print(
        "<input type=\"text\" name=\"chunkSizeToView\" value="
            + chunkSizeToView
            + " size=10 maxlength=10>");
    out.print("&nbsp;&nbsp;<input type=\"submit\" name=\"submit\" value=\"Refresh\"><hr>");
    out.print("<input type=\"hidden\" name=\"filename\" value=\"" + filename + "\">");
    out.print(
        "<input type=\"hidden\" name=\"namenodeInfoPort\" value=\"" + namenodeInfoPort + "\">");
    out.print(
        "<input type=\"hidden\" name=\""
            + JspHelper.NAMENODE_ADDRESS
            + "\" value=\""
            + nnAddr
            + "\">");
    if (!noLink) out.print("<input type=\"hidden\" name=\"referrer\" value=\"" + referrer + "\">");

    // fetch the block from the datanode that has the last block for this file
    final DFSClient dfs = getDFSClient(ugi, nnAddr, conf);
    List<LocatedBlock> blocks =
        dfs.getNamenode().getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
    if (blocks == null || blocks.size() == 0) {
      out.print("No datanodes contain blocks of file " + filename);
      dfs.close();
      return;
    }
    LocatedBlock lastBlk = blocks.get(blocks.size() - 1);
    String poolId = lastBlk.getBlock().getBlockPoolId();
    long blockSize = lastBlk.getBlock().getNumBytes();
    long blockId = lastBlk.getBlock().getBlockId();
    Token<BlockTokenIdentifier> accessToken = lastBlk.getBlockToken();
    long genStamp = lastBlk.getBlock().getGenerationStamp();
    DatanodeInfo chosenNode;
    try {
      chosenNode = JspHelper.bestNode(lastBlk, conf);
    } catch (IOException e) {
      out.print(e.toString());
      dfs.close();
      return;
    }
    InetSocketAddress addr = NetUtils.createSocketAddr(chosenNode.getXferAddr());
    // view the last chunkSizeToView bytes while Tailing
    final long startOffset = blockSize >= chunkSizeToView ? blockSize - chunkSizeToView : 0;

    out.print("<textarea cols=\"100\" rows=\"25\" wrap=\"virtual\" style=\"width:100%\" READONLY>");
    JspHelper.streamBlockInAscii(
        addr,
        poolId,
        blockId,
        accessToken,
        genStamp,
        blockSize,
        startOffset,
        chunkSizeToView,
        out,
        conf);
    out.print("</textarea>");
    dfs.close();
  }
  static void generateFileDetails(JspWriter out, HttpServletRequest req, Configuration conf)
      throws IOException, InterruptedException {

    long startOffset = 0;
    int datanodePort;

    final Long blockId = JspHelper.validateLong(req.getParameter("blockId"));
    if (blockId == null) {
      out.print("Invalid input (blockId absent)");
      return;
    }
    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
    UserGroupInformation ugi = JspHelper.getUGI(req, conf);

    String datanodePortStr = req.getParameter("datanodePort");
    if (datanodePortStr == null) {
      out.print("Invalid input (datanodePort absent)");
      return;
    }
    datanodePort = Integer.parseInt(datanodePortStr);

    final Long genStamp = JspHelper.validateLong(req.getParameter("genstamp"));
    if (genStamp == null) {
      out.print("Invalid input (genstamp absent)");
      return;
    }
    String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
    int namenodeInfoPort = -1;
    if (namenodeInfoPortStr != null) namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);
    final String nnAddr = req.getParameter(JspHelper.NAMENODE_ADDRESS);
    if (nnAddr == null) {
      out.print(JspHelper.NAMENODE_ADDRESS + " url param is null");
      return;
    }

    final int chunkSizeToView =
        JspHelper.string2ChunkSizeToView(
            req.getParameter("chunkSizeToView"), getDefaultChunkSize(conf));

    String startOffsetStr = req.getParameter("startOffset");
    if (startOffsetStr == null || Long.parseLong(startOffsetStr) < 0) startOffset = 0;
    else startOffset = Long.parseLong(startOffsetStr);

    String path = StringEscapeUtils.unescapeHtml(req.getParameter("filename"));
    if (path == null) {
      path = req.getPathInfo() == null ? "/" : req.getPathInfo();
    }
    final String filename = JspHelper.validatePath(path);
    if (filename == null) {
      out.print("Invalid input");
      return;
    }

    final String blockSizeStr = req.getParameter("blockSize");
    if (blockSizeStr == null || blockSizeStr.length() == 0) {
      out.print("Invalid input");
      return;
    }
    long blockSize = Long.parseLong(blockSizeStr);

    final DFSClient dfs = getDFSClient(ugi, nnAddr, conf);
    List<LocatedBlock> blocks =
        dfs.getNamenode().getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
    // Add the various links for looking at the file contents
    // URL for downloading the full file
    String downloadUrl =
        "http://"
            + req.getServerName()
            + ":"
            + req.getServerPort()
            + "/streamFile"
            + ServletUtil.encodePath(filename)
            + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr, true)
            + JspHelper.getDelegationTokenUrlParam(tokenString);
    out.print("<a name=\"viewOptions\"></a>");
    out.print("<a href=\"" + downloadUrl + "\">Download this file</a><br>");

    DatanodeInfo chosenNode;
    // URL for TAIL
    LocatedBlock lastBlk = blocks.get(blocks.size() - 1);
    try {
      chosenNode = JspHelper.bestNode(lastBlk, conf);
    } catch (IOException e) {
      out.print(e.toString());
      dfs.close();
      return;
    }
    String fqdn = canonicalize(chosenNode.getIpAddr());
    String tailUrl =
        "http://"
            + fqdn
            + ":"
            + chosenNode.getInfoPort()
            + "/tail.jsp?filename="
            + URLEncoder.encode(filename, "UTF-8")
            + "&namenodeInfoPort="
            + namenodeInfoPort
            + "&chunkSizeToView="
            + chunkSizeToView
            + JspHelper.getDelegationTokenUrlParam(tokenString)
            + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr)
            + "&referrer="
            + URLEncoder.encode(req.getRequestURL() + "?" + req.getQueryString(), "UTF-8");
    out.print("<a href=\"" + tailUrl + "\">Tail this file</a><br>");

    out.print("<form action=\"/browseBlock.jsp\" method=GET>");
    out.print("<b>Chunk size to view (in bytes, up to file's DFS block size): </b>");
    out.print("<input type=\"hidden\" name=\"blockId\" value=\"" + blockId + "\">");
    out.print("<input type=\"hidden\" name=\"blockSize\" value=\"" + blockSize + "\">");
    out.print("<input type=\"hidden\" name=\"startOffset\" value=\"" + startOffset + "\">");
    out.print("<input type=\"hidden\" name=\"filename\" value=\"" + filename + "\">");
    out.print("<input type=\"hidden\" name=\"genstamp\" value=\"" + genStamp + "\">");
    out.print("<input type=\"hidden\" name=\"datanodePort\" value=\"" + datanodePort + "\">");
    out.print(
        "<input type=\"hidden\" name=\"namenodeInfoPort\" value=\"" + namenodeInfoPort + "\">");
    out.print(
        "<input type=\"hidden\" name=\""
            + JspHelper.NAMENODE_ADDRESS
            + "\" value=\""
            + nnAddr
            + "\">");
    out.print(
        "<input type=\"text\" name=\"chunkSizeToView\" value="
            + chunkSizeToView
            + " size=10 maxlength=10>");
    out.print("&nbsp;&nbsp;<input type=\"submit\" name=\"submit\" value=\"Refresh\">");
    out.print("</form>");
    out.print("<hr>");
    out.print("<a name=\"blockDetails\"></a>");
    out.print("<B>Total number of blocks: " + blocks.size() + "</B><br>");
    // generate a table and dump the info
    out.println("\n<table>");

    String nnCanonicalName = canonicalize(nnAddr);
    for (LocatedBlock cur : blocks) {
      out.print("<tr>");
      final String blockidstring = Long.toString(cur.getBlock().getBlockId());
      blockSize = cur.getBlock().getNumBytes();
      out.print("<td>" + blockidstring + ":</td>");
      DatanodeInfo[] locs = cur.getLocations();
      for (int j = 0; j < locs.length; j++) {
        String datanodeAddr = locs[j].getXferAddr();
        datanodePort = locs[j].getXferPort();
        fqdn = canonicalize(locs[j].getIpAddr());
        String blockUrl =
            "http://"
                + fqdn
                + ":"
                + locs[j].getInfoPort()
                + "/browseBlock.jsp?blockId="
                + blockidstring
                + "&blockSize="
                + blockSize
                + "&filename="
                + URLEncoder.encode(filename, "UTF-8")
                + "&datanodePort="
                + datanodePort
                + "&genstamp="
                + cur.getBlock().getGenerationStamp()
                + "&namenodeInfoPort="
                + namenodeInfoPort
                + "&chunkSizeToView="
                + chunkSizeToView
                + JspHelper.getDelegationTokenUrlParam(tokenString)
                + JspHelper.getUrlParam(JspHelper.NAMENODE_ADDRESS, nnAddr);

        String blockInfoUrl =
            "http://"
                + nnCanonicalName
                + ":"
                + namenodeInfoPort
                + "/block_info_xml.jsp?blockId="
                + blockidstring;
        out.print(
            "<td>&nbsp</td><td><a href=\""
                + blockUrl
                + "\">"
                + datanodeAddr
                + "</a></td><td>"
                + "<a href=\""
                + blockInfoUrl
                + "\">View Block Info</a></td>");
      }
      out.println("</tr>");
    }
    out.println("</table>");
    out.print("<hr>");
    out.print(
        "<br><a href=\"http://"
            + nnCanonicalName
            + ":"
            + namenodeInfoPort
            + "/dfshealth.jsp\">Go back to DFS home</a>");
    dfs.close();
  }