package com.mycompany.jsf.servlets;
import com.mycompany.jsf.model.TreeNode;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLEncoder;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
* This class is a servlet that produces a response showing the
* state captured by the CaptureStatePhaseListener, as a tree
* with links for opening and closing nodes.
*
* @author Hans Bergsten, Gefion Software <hans@gefionsoftware.com>
* @version 1.0
*/
public class ShowViewStateServlet extends HttpServlet {
/**
* If invoked without a "viewId" parameter, renders a response
* with links back to itself for all views available in the
* session scope variable "com.mycompany.debug". Otherwise,
* toggles the "expanded" flag for the node identified by the
* "nodeId" parameter (if any) and renders the view state
* tree by calling renderDocument().
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
HttpSession session = request.getSession();
Map debugMap = (Map) session.getAttribute("com.mycompany.debug");
if (debugMap == null) {
response.sendError(HttpServletResponse.SC_BAD_REQUEST,
"No state available");
return;
}
String uri = request.getContextPath() + request.getServletPath();
String viewId = request.getParameter("viewId");
if (viewId == null) {
renderLinks(debugMap, out, uri);
}
else {
TreeNode root = (TreeNode) debugMap.get(viewId);
if (root == null) {
response.sendError(HttpServletResponse.SC_BAD_REQUEST,
"No state for viewId parameter");
return;
}
String path = request.getParameter("nodePath");
if (path != null) {
toggleExpanded(path, root);
}
renderDocument(root, out, viewId, uri);
}
}
/**
* Renders a response with links for all views in the Map.
*/
private void renderLinks(Map debugMap, PrintWriter out, String uri) {
out.println("<html>");
out.println(" <head>");
out.println(" <title>Debug info for views</title>");
out.println(" </head>");
out.println(" <body bgcolor=\"white\">");
out.println(" Info for the following views is available:");
out.println(" <ul>");
Iterator i = debugMap.keySet().iterator();
while (i.hasNext()) {
String viewId = (String) i.next();
out.println(indent(3) + "<li><a href=\"" + uri +
"?viewId=" + URLEncoder.encode(viewId) +
"\">" + viewId + "</a></li>");
}
out.println(" </body>");
out.println("</html>");
}
/**
* Locates the node with the specified path in the tree and
* flips its "expanded" flag.
*/
private void toggleExpanded(String path, TreeNode root) {
List kids = root.getChildren();
boolean foundElement = false;
TreeNode matchingNode = null;
StringTokenizer st = new StringTokenizer(path, "/");
// Throw away the root token
st.nextToken();
while (st.hasMoreTokens()) {
String t = st.nextToken();
for (int i = 0; i < kids.size(); i++) {
TreeNode kid = (TreeNode) kids.get(i);
if (t.equals(kid.getName())) {
matchingNode = kid;
kids = kid.getChildren();
foundElement = true;
break;
}
}
if (!foundElement) {
break;
}
}
if (matchingNode != null) {
boolean isExpanded = matchingNode.isExpanded();
matchingNode.setExpanded(!isExpanded);
}
}
/**
* Renders the "html", "head" and "body" elements and calls
* the renderTreeNode() method to render the tree.
*/
private void renderDocument(TreeNode root, PrintWriter out,
String viewId, String uri) {
out.println("<html>");
out.println(" <head>");
out.println(" <title>Info for view '" + viewId + "'</title>");
out.println(" </head>");
out.println(" <body bgcolor=\"white\">");
renderTreeNode(root, out, viewId, uri, 2, "0", 0);
out.println(" </body>");
out.println("</html>");
}
/**
* Renders the node, as "name=value" if it's a leaf node or as a
* link for expanding or collapsing the node otherwise. If the
* node is expanded, calls itself recursively for all node
* children, rendering the children within a "blockquote" element.
*/
private void renderTreeNode(TreeNode node, PrintWriter out,
String viewId, String uri, int level,
String parentNodeId, int childId) {
if (node.isLeafNode()) {
out.println(indent(level) + node.getName() + " = " +
node.getValue() + "<br>");
}
else {
String nodeId = parentNodeId + ":" + childId;
out.println(indent(level) + "<a id=\"" + nodeId +
"\" href=\"" + uri +
"?viewId=" + URLEncoder.encode(viewId) +
"&nodePath=" +
URLEncoder.encode(node.getPath()) +
"&expand=" + (!node.isExpanded()) +
"#" + nodeId +
"\">" + (node.isExpanded() ? "-" : "+") +
"</a> " + node.getName() + "<br>");
if (node.isExpanded()) {
out.println(indent(level + 1) + "<blockquote>");
int kidId = 0;
Iterator i = node.getChildren().iterator();
while (i.hasNext()) {
TreeNode kid = (TreeNode) i.next();
renderTreeNode(kid, out, viewId, uri, level + 2, nodeId,
kidId++);
}
out.println(indent(level + 1) + "</blockquote>");
}
}
}
/**
* Returns a blank String of the appropriate length for the indention
* level.
*/
private String indent(int level) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < level; i++) {
sb.append(" ");
}
return sb.toString();
}
}
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