z2-Environment

/*

 * z2-Environment

 * 

 * Copyright(c) ZFabrik Software KG

 * 

 * contact@zfabrik.de

 * 

 * http://www.z2-environment.eu

 */

package com.zfabrik.impl.javadoc;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.util.Collection;

import java.util.TreeSet;

import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.zfabrik.components.IComponentDescriptor;

import com.zfabrik.components.IComponentsManager;

import com.zfabrik.components.java.IJavaComponent;

import com.zfabrik.components.java.JavaComponentUtil;

import com.zfabrik.util.expression.X;

import com.zfabrik.util.html.Escaper;

/**

 * Java Doc filter - serves and triggers on-demand creation of java component

 * java docs

 * 

 * @author hb

 * 

 */

public class JDocFilter implements Filter {

	private static final String LAST_MODIFIED = "Last-Modified";

	private static final String IF_MODIFIED_SINCE = "If-Modified-Since";

	private FilterConfig cfg;

	public void init(FilterConfig cfg) throws ServletException {

		this.cfg = cfg;

	}

	public void destroy() {

		this.cfg = null;

	}

	public void doFilter(ServletRequest req, ServletResponse res,FilterChain chain) throws IOException, ServletException {

		HttpServletRequest sreq = (HttpServletRequest) req;

		HttpServletResponse resp = (HttpServletResponse) res;

		// paths are /<component>/<api|impl>/<jdoc path>

		String path = sreq.getRequestURI().substring(sreq.getContextPath().length());

		if (path.length() > 1) {

			int p = path.indexOf('/', 1);

			if (p >= 0) {

				String component = Escaper.urlDecode(path.substring(1, p),'!');

				component = JavaComponentUtil.fixJavaComponentName(component);

				path = path.substring(p);

				if (path.length() > 1) {

					p = path.indexOf('/', 1);

					if (p >= 0) {

						String type = Escaper.urlDecode(path.substring(1, p),'!');

						File f = checkDocs(component, type);

						if (f != null) {

							path = path.substring(p);

							if (path.length()>0) {

								f = new File(f, path);

								if (f.exists()) {

									// check last modified request

									long ifModifiedSince = sreq	.getDateHeader(IF_MODIFIED_SINCE);

									if (ifModifiedSince >= 0) {

										// make sure to reduce to seconds precision!

										long cr = f.lastModified();

										if (((cr / 1000) * 1000) <= ifModifiedSince) {

											// nothing to do...

											resp.setStatus(HttpServletResponse.SC_NOT_MODIFIED);

											return;

										}

									}

									// ok, write it out

									// headers

									// Important: set Last-Modified!

									resp.setDateHeader(LAST_MODIFIED, f.lastModified());

									resp.setContentType(this.cfg.getServletContext().getMimeType(f.getName()));

									resp.setContentLength((int) f.length());

									// stream out

									OutputStream out = resp.getOutputStream();

									InputStream in = new FileInputStream(f);

									try {

										byte[] buffer = new byte[16384];

										int l;

										while ((l = in.read(buffer)) >= 0) {

											out.write(buffer, 0, l);

										}

									} finally {

										in.close();

									}

									return;

								}

							} else {

								// url ends after type string. redirect

								redirect2Index(sreq,resp);

								return;

							}

						} else {

							// not found

							gotoList(sreq,resp,true);

							return;

						}

					} else {

						// url ends at type string. redirect

						redirect2Index(sreq,resp);

						return;

					}

				} else {

					// url ends at component

					redirect2Index(sreq,resp);

					return;

				}

			} else {

				// url ends at component

				redirect2Index(sreq,resp);

				return;

			}

		} else {

			// index

			gotoList(sreq,resp,false);

			return;

		}

		resp.setStatus(HttpServletResponse.SC_NOT_FOUND);

		chain.doFilter(req,res);

	}

	private void gotoList(HttpServletRequest sreq, HttpServletResponse resp,boolean notfound) throws IOException, ServletException {

		// present a choice of components

		sreq.setAttribute("notfound", notfound);

		Collection<String> cs = IComponentsManager.INSTANCE.findComponents(X.var(IComponentDescriptor.COMPONENT_TYPE).eq(X.val(IJavaComponent.TYPE_NAME)));

		TreeSet<String> scs = new TreeSet<String>(cs);

		sreq.setAttribute("components", scs);

		sreq.getRequestDispatcher("/WEB-INF/all.jsp").forward(sreq, resp);		

	}

	private void redirect2Index(HttpServletRequest sreq,HttpServletResponse resp) throws IOException, ServletException {

		String s = sreq.getRequestURI();

		if (!s.endsWith("/")) {

			s += "/";

		}

		if (s.endsWith("/api/") || s.endsWith("/impl/")) {

			resp.sendRedirect(s+"index.html");

		} else {

			resp.sendRedirect(s+"api/index.html");

		}

	}

	/*

	 * Check for javadocs of the given type from the given component.

	 * If not found, trigger creation

	 */

	private File checkDocs(String component, String type) {

		short t = 0;

		if ("both".equals(type)) {

			t = ComponentJavaDoc.TYPE_BOTH;

		} else 

		if ("impl".equals(type)) {

			t = ComponentJavaDoc.TYPE_IMPL;

		} else 

		if ("api".equals(type)) {

			t = ComponentJavaDoc.TYPE_API;

		} else 

			return null;

		return new ComponentJavaDoc(component,t).getRootFolder();

	}

}