Java tutorial
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package org.sparqlbuilder.www; import org.sparqlbuilder.core.Path; import org.sparqlbuilder.core.ClassLink; import org.sparqlbuilder.core.Direction; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.Iterator; import java.util.List; import java.util.logging.Level; import java.util.logging.Logger; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; //import javax.json.Json; /** * * @author atsuko */ @WebServlet(name = "SPServlet", urlPatterns = { "/sparql" }) public class SPServlet extends HttpServlet { /** * Processes requests for both HTTP <code>GET</code> and <code>POST</code> * methods. * * @param request servlet request * @param response servlet response * @throws ServletException if a servlet-specific error occurs * @throws IOException if an I/O error occurs */ protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); try (PrintWriter out = response.getWriter()) { /* TODO output your page here. You may use following sample code. */ out.println("<!DOCTYPE html>"); out.println("<html>"); out.println("<head>"); out.println("<title>Servlet SPServlet</title>"); out.println("</head>"); out.println("<body>"); out.println("<h1>Servlet SPServlet at " + request.getContextPath() + "</h1>"); out.println("</body>"); out.println("</html>"); } } // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code."> /** * Handles the HTTP <code>GET</code> method. * * @param request servlet request * @param response servlet response * @throws ServletException if a servlet-specific error occurs * @throws IOException if an I/O error occurs */ @Override /* protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); }*/ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //processRequest(request, response); response.setContentType("application/json;charset=UTF-8"); response.setHeader("Access-Control-Allow-Origin", "*"); response.setHeader("Access-Control-Allow-Methods", "GET"); response.setHeader("Access-Control-Allow-Headers", request.getHeader("Access-Control-Request-Headers")); response.setHeader("Access-Control-Max-Age", "-1"); PrintWriter out = response.getWriter(); String jpath = request.getParameter("path"); System.out.println("Path"); System.out.println(jpath); Path path = null; try { path = convertJ2Path(jpath); } catch (JSONException ex) { Logger.getLogger(SPServlet.class.getName()).log(Level.SEVERE, null, ex); } String query = null; try { query = convertPath2SPARQL(path); } catch (Exception ex) { Logger.getLogger(SPServlet.class.getName()).log(Level.SEVERE, null, ex); } out.print(query); } /** * Handles the HTTP <code>POST</code> method. * * @param request servlet request * @param response servlet response * @throws ServletException if a servlet-specific error occurs * @throws IOException if an I/O error occurs */ @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } /** * Returns a short description of the servlet. * * @return a String containing servlet description */ @Override public String getServletInfo() { return "Short description"; }// </editor-fold> private Path convertJ2Path(String jpath) throws JSONException { JSONObject object = new JSONObject(jpath); // int width = Integer.parseInt(object.getJSONObject("width").toString()); JSONArray classLinks = object.getJSONArray("classLinks"); JSONObject jsonObject; List<ClassLink> list = new ArrayList<ClassLink>(); for (int i = 0; i < classLinks.length(); i++) { jsonObject = classLinks.getJSONObject(i); String direction = jsonObject.getString("direction"); Direction myDirection = null; if (direction.equals(Direction.forward.toString())) myDirection = Direction.forward; else if (direction.equals(Direction.reverse.toString())) myDirection = Direction.reverse; else if (direction.equals(Direction.both.toString())) myDirection = Direction.both; String linkedLiteralDatatypeURI = null; // linkedLiteralDatatypeURI = jsonObject.getString("linkedLiteralDatatypeURI"); String linkedClassURI = jsonObject.getString("linkedClass"); String propertyURI = jsonObject.getString("predicate"); // int numOfLinks = Integer.parseInt(jsonObject.getJSONObject("numOfLinks").toString()); // int numOfLinkedInstances = Integer.parseInt(jsonObject.getJSONObject("numOfLinkedInstances").toString()); // int numOfOriginInstances = Integer.parseInt(jsonObject.getJSONObject("numOfOriginInstances").toString()); // int numOfOriginClassInstances = Integer.parseInt(jsonObject.getJSONObject("numOfOriginInstances").toString()); // int numOfLinkedClassInstances = Integer.parseInt(jsonObject.getJSONObject("numOfLinkedClassInstances").toString()); // ClassLink classLink =new ClassLink(propertyURI, linkedClassURI, linkedLiteralDatatypeURI, null, // numOfLinks, numOfOriginInstances, numOfLinkedInstances, // numOfOriginClassInstances, numOfLinkedClassInstances, // false, false); ClassLink classLink = new ClassLink(propertyURI, linkedClassURI, linkedLiteralDatatypeURI, myDirection, 0, 0, 0, 0, 0, false, false); System.out.println(classLink.getDirection().toString()); list.add(classLink); } String startClass = object.getString("startClass"); Path path = new Path(startClass, list, 0); return path; } private String convertPath2SPARQL(Path path) throws Exception { ArrayList<String> classname = new ArrayList<String>(); if (path == null) { throw new Exception("Path is null."); } String startClass = path.getStartClass(); List<ClassLink> classLinks = path.getClassLinks(); StringBuffer queryStr = new StringBuffer(); StringBuffer selStr = new StringBuffer(); StringBuffer whereStr = new StringBuffer(); // if(num==0){ int num = classLinks.size(); // } queryStr.append("PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>\n"); queryStr.append("PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>\n"); selStr.append("SELECT "); whereStr.append("WHERE { \n"); String properties = null; String objectClasses = null; String subjectClasses = null; Direction direction = null; int i = 0; int k = 0; for (ClassLink link : classLinks) { properties = link.getPropertyURI(); objectClasses = link.getLinkedClassURI(); direction = link.getDirection(); if (i == 0) subjectClasses = startClass; classname.add(subjectClasses); selStr.append("?c").append(i).append(" "); selStr.append("?l").append(i).append(" "); if (i == classLinks.size()) selStr.append("\n"); whereStr.append("?c").append(i).append(" rdf:type ").append("<").append(subjectClasses).append(">") .append(".\n"); whereStr.append("OPTIONAL{\n?c" + i + " rdfs:label ?l" + i + ".}\n"); if (direction == Direction.forward) { whereStr.append("?c").append(i).append(" "); whereStr.append("<").append(properties).append("> "); whereStr.append("?c").append(i + 1).append(".\n"); } else { whereStr.append("?c").append(i + 1).append(" "); whereStr.append("<").append(properties).append("> "); whereStr.append("?c").append(i).append(".\n"); } subjectClasses = objectClasses; i++; k++; if (k >= num) { break; } } selStr.append("?c").append(i).append(" \n"); selStr.append("?l").append(i).append(" \n"); whereStr.append("?c").append(i).append(" rdf:type ").append("<").append(subjectClasses).append(">") .append(".\n"); whereStr.append("OPTIONAL{\n?c" + i + " rdfs:label ?l" + i + ".}\n"); classname.add(subjectClasses); queryStr.append(selStr).append(whereStr); queryStr.append("}"); //OPTIONAL queryStr.append("LIMIT 100\n"); System.out.println(queryStr); //rewrite Sparql ArrayList<String> classname2 = new ArrayList<String>(); for (int index = 0; index < classname.size(); index++) { String tmp = classname.get(index); /* int mark; if((mark=tmp.indexOf("#"))!=-1) classname2.add(tmp.substring(mark+1)); else classname2.add(tmp.substring(tmp.indexOf("/")+1)); */ // changed by Atsuko String[] sname1 = tmp.split("#"); String[] sname2 = sname1[sname1.length - 1].split("/"); String[] sname3 = sname2[sname2.length - 1].split(":"); String cname = sname3[sname3.length - 1].replaceAll("-", ""); classname2.add(cname); } String query = queryStr.toString(); for (int index = 0; index < classname2.size(); index++) { String original = "c" + index; query = query.replaceAll(original, classname2.get(index)); } query = query.replaceAll("\\?l", "\\?label"); System.out.println(query); return query; } private static String rewriteSparql(String query) { StringBuffer tmp = new StringBuffer(query); int index = tmp.indexOf("WHERE"); int begin = 0, cnt = 0; while (begin < index) { begin = tmp.indexOf("?c", begin); cnt++; } return null; } private static List<String> convertJ2Path2(String jpath) throws JSONException { List<String> list = null; String temp = (String) jpath.subSequence(2, jpath.length() - 2); // if (temp.contains(","")) list = Arrays.asList(temp.split("\",\"")); return list; /* JSONArray classLinks=new JSONArray(jpath); String string; for (int i=0;i<classLinks.length();i++) { string = classLinks.getJSONObject(i).toString(); if (string.contains(",")) { list =Arrays.asList(string.split(",")); } else throw new IllegalArgumentException("path error"); }*/ // return list; } private static String convertPath2SPARQL2(List<String> path) throws Exception { if (path == null) { throw new Exception("Path is null."); } //List<String> classLinks = path.getClassLinks(); StringBuffer queryStr = new StringBuffer(); StringBuffer selStr = new StringBuffer(); StringBuffer whereStr = new StringBuffer(); // if(num==0){ // int num = classLinks.size(); // } queryStr.append("PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>\n"); queryStr.append("PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>\n"); selStr.append("SELECT "); whereStr.append("WHERE { \n"); String properties = null; String objectClasses = null; String subjectClasses = null; Direction direction = null; int i = 0; int k = 0; String startClass = path.get(path.size() - 1); List<String> classLinks = null; // ArrayList<String> array= (String[])path.toArray(); // classLinks.add(path.get(i)); int num = (path.size() - 1) / 2; for (int j = path.size() - 2; j > 0; j = j - 2) { // properties = link.getPropertyURI(); // objectClasses = link.getLinkedClassURI(); // direction = link.getDirection(); properties = path.get(j); objectClasses = path.get(j - 1); direction = Direction.forward; if (i == 0) subjectClasses = startClass; selStr.append("?c").append(i).append(" "); selStr.append("?l").append(i).append(" "); // if(i == path.size()) // selStr.append("\n"); whereStr.append("?c").append(i).append(" rdf:type ").append("<").append(subjectClasses).append(">") .append(".\n"); whereStr.append("OPTIONAL{\n?c" + i + " rdfs:label ?l" + i + ".}\n"); if (direction == Direction.forward) { whereStr.append("?c").append(i).append(" "); whereStr.append("<").append(properties).append("> "); whereStr.append("?c").append(i + 1).append(".\n"); } else { whereStr.append("?c").append(i + 1).append(" "); whereStr.append("<").append(properties).append("> "); whereStr.append("?c").append(i).append(".\n"); } subjectClasses = objectClasses; i++; k++; if (k >= num) { break; } } selStr.append("?c").append(i).append(" \n"); selStr.append("?l").append(i).append(" \n"); whereStr.append("?c").append(i).append(" rdf:type ").append("<").append(subjectClasses).append(">") .append(".\n"); whereStr.append("OPTIONAL{\n?c" + i + " rdfs:label ?l" + i + ".}\n"); queryStr.append(selStr).append(whereStr); queryStr.append("}"); //OPTIONAL queryStr.append("LIMIT 100\n"); ; System.out.println(queryStr); return queryStr.toString(); } }