This example code, in conjunction with the code in the other two example files, displays an HTMLTree and FileListElement in a servlet. The three files in the example are:
//////////////////////////////////////////////////////////////////////////////////
//
// This source is an example of using the IBM Toolbox for Java HTML
// package classes, which allow you to easily build HTML and File Trees.
//
//////////////////////////////////////////////////////////////////////////////////
import java.io.File;
import java.io.PrintWriter;
import java.io.IOException;
import javax.servlet.*;
import javax.servlet.http.*;
import com.ibm.as400.access.AS400;
import com.ibm.as400.access.IFSJavaFile;
import com.ibm.as400.util.html.HTMLMeta;
import com.ibm.as400.util.html.HTMLTree;
import com.ibm.as400.util.html.HTMLTreeElement;
import com.ibm.as400.util.html.URLParser;
import com.ibm.as400.util.html.DirFilter;
import com.ibm.as400.util.html.FileTreeElement;
import com.ibm.as400.util.servlet.ServletHyperlink;
//
// An example of using the HTMLTree and FileTreeElement classes
// in a servlet.
//
public class TreeNav extends HttpServlet
{
private AS400 sys_;
public void init(ServletConfig config)
throws ServletException
{
super.init(config);
// Create an AS400 object.
sys_ = new AS400("mySystem", "myUserID", "myPassword");
// IBM Toolbox for Java uses a set of default icons to represents expanded,
// collapsed, and documents within the HTMLTree. To enhance those icons,
// IBM Toolbox for Java ships three gifs (expanded.gif, collapsed.gif, bullet.gif)
// in the jt400Servlet.jar file. Browsers do not have the ability to find
// gifs in a jar or zip file, so you need to extract those images from the
// jar file and place them in the appropriate webserver directory (by default
// it is the /html directory). Then change the following lines of code to
// specify the correct location in the set methods. The location can be
// absolute or relative.
HTMLTreeElement.setExpandedGif("http://myServer/expanded.gif");
HTMLTreeElement.setCollapsedGif("http://myServer/collapsed.gif");
HTMLTreeElement.setDocGif("http://myServer/bullet.gif");
}
/**
* Process the GET request.
* @param req The request.
* @param res The response.
**/
public void doGet (HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
// Use session data to remember the state of the tree.
HttpSession session = req.getSession(true);
HTMLTree fileTree = (HTMLTree)session.getValue("filetree");
// If this session does not already have a file tree, then
// create the initial tree.
if (fileTree == null)
fileTree = createTree(req, resp, req.getRequestURI());
// Set the Http servlet request on the HTMLTree.
fileTree.setHttpServletRequest(req);
resp.setContentType("text/html");
PrintWriter out = resp.getWriter();
out.println("<html>\n");
out.println(new HTMLMeta("Expires","Mon, 03 Jan 1990 13:00:00 GMT"));
out.println("<body>\n");
// Get the tag for the HTMLTree.
out.println(fileTree.getTag());
out.println("</body>\n");
out.println("</html>\n");
out.close();
// Set the session tree value, so when entering this servlet for
// the second time, the FileTree object will be reused.
session.putValue("filetree", fileTree);
}
/**
* Process the POST request.
* @param req The request.
* @param res The response.
**/
public void doPost (HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException
{
res.setContentType("text/html");
ServletOutputStream out = res.getOutputStream();
}
/**
* This method will create the initial HTMLTree.
**/
private HTMLTree createTree(HttpServletRequest req,
HttpServletResponse resp, String uri)
{
// Create an HTMLTree object.
HTMLTree tree = new HTMLTree(req);
try
{
// Create a URLParser object.
URLParser urlParser = new URLParser(uri);
// Create a File object and set the root IFS directory.
IFSJavaFile root = new IFSJavaFile(sys_, "/QIBM");
// Create a Filter.
DirFilter filter = new DirFilter();
// Get the list of files that satisfy the directory filter.
String[] list = root.list(filter);
File[] dirList = new File[list.length];
// We don't want to require webservers to use JDK1.2 because
// most webserver JVM's are slower to upgrade to the latest
// JDK level. The most efficient way to create these file objects
// is to use the listFiles(filter) method in JDK1.2 which would
// be done like the following, instead of using the list(filter)
// method and then converting the returned string arrary into the
// appropriate File array.
// File[] dirList = root.listFiles(filter);
for (int j=0; j<dirList.length; ++j)
{
if (root instanceof IFSJavaFile)
dirList[j] = new IFSJavaFile((IFSJavaFile)root, list[j]);
else
dirList[j] = new File(list[j]);
}
for (int i=0; i<dirList.length; i++)
{
// Create a FileTreeElement for each directory in the list.
FileTreeElement node = new FileTreeElement(dirList[i]);
// Create a ServletHyperlink for the expand/collapse icons.
ServletHyperlink sl = new ServletHyperlink(urlParser.getURI());
sl.setHttpServletResponse(resp);
node.setIconUrl(sl);
// Create a ServletHyperlink to the TreeList servlet, which will
// display the contents of thie FileTreeElement (directory).
ServletHyperlink tl = new ServletHyperlink("/servlet/TreeList");
tl.setTarget("list");
// If the ServletHyperlink doesn't have a name, then set it to the
// name of the directory.
if (tl.getText() == null)
tl.setText(dirList[i].getName());
// Set the TextUrl for the FileTreeElement.
node.setTextUrl(tl);
// Add the FileTreeElement to the HTMLTree.
tree.addElement(node);
}
sys_.disconnectAllServices();
}
catch (Exception e)
{
e.printStackTrace();
}
return tree;
}
public void destroy(ServletConfig config)
{
// do nothing
}
public String getServletInfo()
{
return "FileTree Navigation";
}
}