package dli2fe.helpers;/** * Title:        Digial Library Interoperable Interface Fudan Edition * Description:  This project contains all the classes required for DLI2FE interface. Developers use these classes to implement the wrapper and client side codes. The basic functions of DLI2FE is as follows: * Search: Search a digital library source site. * Metadata: Fetch metadata for a site. * ResultAccess: Get results for a given query. * DLI2FE uses Dublin Core as the basic attribute model, DAV/DASL as the general XML-based query language and CORBA as distributed object transportation mechanism. * Copyright:    Copyright (c) 2001 * Company:      Fudan University * @author Carl Tao * @version 1.0 */import org.w3c.dom.*;import dli2fe.xml.XMLObject;import dli2fe.DLI2FEException;import dli2fe.xml.DOMUtil;import dli2fe.sample.MultimediaMeta;import dli2fe.DAV;public class MMQueryDecomposer {  XMLObject metaQuery;  String image;  String pfeedback;  String nfeedback;  boolean isAnd;  public MMQueryDecomposer(XMLObject query) throws DLI2FEException {    metaQuery = query;    image=null;    pfeedback=null;    nfeedback=null;    isAnd = false;    Element where = DOMUtil.getChild(query.getElement(), DAV.where);    if (where == null) {      throw new DLI2FEException(DLI2FEException.BAD_QUERY_EXC, "No where clause specified: " + query.getString());    }    Element firstChildOfWhere = DOMUtil.getChild(where, "*");    // 如果Where子句的直接兒子是邏輯操作符    if (firstChildOfWhere != null && (DAV.and.equals(firstChildOfWhere.getLocalName()) || DAV.or.equals(firstChildOfWhere.getLocalName()))) {      isAnd = DAV.and.equals(firstChildOfWhere.getLocalName());      Element elMM;                                       // 用來存儲(chǔ)多媒體屬性的Element      Element condImage=null, condPFeedback=null, condNFeedback=null;    // 用來存儲(chǔ)多媒體條件的Elements      if ((elMM = DOMUtil.getDescendant((Element)firstChildOfWhere, MultimediaMeta.Namespace, MultimediaMeta.image))!=null) {        condImage = (Element)elMM.getParentNode().getParentNode();        image = DOMUtil.getDescendantText(condImage, DAV.literal);      }      if ((elMM = DOMUtil.getDescendant((Element)firstChildOfWhere, MultimediaMeta.Namespace, MultimediaMeta.pfeedback))!=null) {        condPFeedback = (Element)elMM.getParentNode().getParentNode();        pfeedback = DOMUtil.getDescendantText(condPFeedback, DAV.literal);      }      if ((elMM = DOMUtil.getDescendant((Element)firstChildOfWhere, MultimediaMeta.Namespace, MultimediaMeta.nfeedback))!=null) {        condNFeedback = (Element)elMM.getParentNode().getParentNode();        nfeedback = DOMUtil.getDescendantText(condNFeedback, DAV.literal);      }      // 如果根本沒有多媒體查詢條件，直接返回      if (condImage == null)        return;      // 如果各個(gè)多媒體條件的父節(jié)點(diǎn)不同，則查詢語句有語法錯(cuò)      if (condPFeedback != null && condImage.getParentNode() != condPFeedback.getParentNode()        || condNFeedback != null && condImage.getParentNode() != condNFeedback.getParentNode())        throw new DLI2FEException(DLI2FEException.BAD_QUERY_EXC, "Unparelleled multimedia conditions: " + query.getString());      // 刪除多媒體查詢條件      Element parentCond = (Element)condImage.getParentNode();      parentCond.removeChild(condImage);      if (condPFeedback != null)        parentCond.removeChild(condPFeedback);      if (condNFeedback != null)        parentCond.removeChild(condNFeedback);      // 向上遍歷直到刪除所有因刪除多媒體條件導(dǎo)致的空節(jié)點(diǎn)      while (DOMUtil.getChild(parentCond, "*") == null && !(DAV.where.equals(parentCond.getLocalName()))) {        Element oldParent = parentCond;        parentCond = (Element)oldParent.getParentNode();        parentCond.removeChild(oldParent);      }    // 否則如果Where子句只包含image屬性的唯一條件    } else if (firstChildOfWhere != null && DOMUtil.getDescendant(firstChildOfWhere, MultimediaMeta.Namespace, MultimediaMeta.image)!=null) {      image = DOMUtil.getDescendantText(firstChildOfWhere, DAV.literal);      metaQuery = null;    // 如果Where子句沒有條件，產(chǎn)生異常    } else if (firstChildOfWhere == null)      throw new DLI2FEException(DLI2FEException.BAD_QUERY_EXC, "Null query: " + query.getString());  }  public XMLObject getMetaQuery() {    return metaQuery;  }  public String getQueryImage() {    return image;  }  public String getQueryPFeedback() {    return pfeedback;  }  public String getQueryNFeedback() {    return nfeedback;  }  public boolean isAnd() {    return isAnd;  }  public static void main(String[] args) {    try {      //XMLObject xq = new XMLObject("<?xml version=\"1.0\" encoding=\"GB2312\" ?><basicsearch xmlns=\"http://www.cs.fudan.edu.cn/DLI2FE/1.0#\" xmlns:dc=\"http://purl.org/metadata/dublin_core#\" xmlns:mm=\"http://www.cs.fudan.edu.cn/multimedia/#\"> <where>   <like>  <prop><mm:image/></prop>   <literal>file://D:\\Temp\\bookinput.jpg</literal>   </like> </where> </basicsearch>");      //XMLObject xq = new XMLObject("<?xml version=\"1.0\" encoding=\"GB2312\" ?><basicsearch xmlns=\"http://www.cs.fudan.edu.cn/DLI2FE/1.0#\" xmlns:dc=\"http://purl.org/metadata/dublin_core#\" xmlns:mm=\"http://www.cs.fudan.edu.cn/multimedia/#\"> <where>   <and>  <like>  <prop><mm:image/></prop>   <literal>file://D:\\Temp\\bookinput.jpg</literal>   </like> <eq><prop><mm:pfeedback/></prop><literal>4+5+</literal> </eq><eq><prop><mm:nfeedback/></prop><literal>3+2+</literal> </eq></and></where> </basicsearch>");      //XMLObject xq = new XMLObject("<?xml version=\"1.0\" encoding=\"GB2312\" ?><basicsearch xmlns=\"http://www.cs.fudan.edu.cn/DLI2FE/1.0#\" xmlns:dc=\"http://purl.org/metadata/dublin_core#\" xmlns:mm=\"http://www.cs.fudan.edu.cn/multimedia/#\"> <where>  <and>  <eq>     <prop><dc:Contributor><dc:Translator/></dc:Contributor></prop> <literal>施伯樂</literal> </eq> <and>  <like>  <prop><mm:image/></prop>   <literal>file://D:\\Temp\\bookinput.jpg</literal>   </like> <eq><prop><mm:pfeedback/></prop><literal>4+5+</literal> </eq><eq><prop><mm:nfeedback/></prop><literal>3+2+</literal> </eq></and></and> </where> </basicsearch>");      //XMLObject xq = new XMLObject("<?xml version=\"1.0\" encoding=\"GB2312\" ?><basicsearch xmlns=\"http://www.cs.fudan.edu.cn/DLI2FE/1.0#\" xmlns:dc=\"http://purl.org/metadata/dublin_core#\" xmlns:mm=\"http://www.cs.fudan.edu.cn/multimedia/#\"> <where>  <like>  <prop><mm:image/></prop>   <literal>file://D:\\Temp\\bookinput.jpg</literal>   </like>  </where> </basicsearch>");      XMLObject xq = new XMLObject("<?xml version='1.0' encoding='GB2312' ?><basicsearch xmlns='http://www.cs.fudan.edu.cn/DLI2FE/1.0#' xmlns:mm='http://www.cs.fudan.edu.cn/multimedia/#' xmlns:ts='http://cs.fudan.edu.cn/travel/#'><where><like><prop><mm:image/></prop><literal>http://localhost:8080/multimediasearch/tempsample/first.jpg</literal></like></where></basicsearch>");      System.out.println(xq.getString());      MMQueryDecomposer qd = new MMQueryDecomposer(xq);      if (qd.getMetaQuery() != null)        System.out.println(qd.getMetaQuery().getString());      else        System.out.println(qd.getMetaQuery());      System.out.println(qd.getQueryImage());      System.out.println(qd.getQueryPFeedback());      System.out.println(qd.getQueryNFeedback());    } catch (DLI2FEException ex) {      System.out.println(ex);    }  }}