Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* This file is part of *** M y C o R e ***
* See http://www.mycore.de/ for details.
*
* MyCoRe is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* MyCoRe is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MyCoRe. If not, see .
*/
package org.mycore.services.fieldquery;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.jdom2.Element;
import org.mycore.parsers.bool.MCRAndCondition;
import org.mycore.parsers.bool.MCRBooleanClauseParser;
import org.mycore.parsers.bool.MCRCondition;
import org.mycore.parsers.bool.MCRNotCondition;
import org.mycore.parsers.bool.MCROrCondition;
import org.mycore.parsers.bool.MCRParseException;
import org.mycore.parsers.bool.MCRSetCondition;
import com.ibm.icu.util.Calendar;
import com.ibm.icu.util.GregorianCalendar;
/**
* Parses query conditions for use in MCRSearcher.
*
* @author Frank Lützenkirchen
*/
public class MCRQueryParser extends MCRBooleanClauseParser {
/**
* Parses XML element containing a simple query condition
*
* @param e
* the 'condition' element
* @return the parsed MCRQueryCondition object
*/
@Override
protected MCRCondition parseSimpleCondition(Element e) throws MCRParseException {
String name = e.getName();
if (!name.equals("condition")) {
throw new MCRParseException("Not a valid <" + name + ">");
}
String field = e.getAttributeValue("field");
String opera = e.getAttributeValue("operator");
String value = e.getAttributeValue("value");
return buildConditions(field, opera, value);
}
/**
* Builds a new MCRCondition from parsed elements
*
* @param field
* one or more field names, separated by comma
* @param oper
* the condition operator
* @param value
* the condition value
* @return
*/
private MCRCondition buildConditions(String field, String oper, String value) {
if (field.contains(",")) { // Multiple fields in one condition, combine with OR
StringTokenizer st = new StringTokenizer(field, ", ");
MCROrCondition oc = new MCROrCondition<>();
while (st.hasMoreTokens()) {
oc.addChild(buildConditions(st.nextToken(), oper, value));
}
return oc;
} else if (field.contains("-")) { // date condition von-bis
StringTokenizer st = new StringTokenizer(field, "- ");
String fieldFrom = st.nextToken();
String fieldTo = st.nextToken();
if (oper.equals("=")) {
// von-bis = x --> (von <= x) AND (bis >= x)
MCRAndCondition ac = new MCRAndCondition<>();
ac.addChild(buildCondition(fieldFrom, "<=", value));
ac.addChild(buildCondition(fieldTo, ">=", value));
return ac;
} else if (oper.contains("<")) {
return buildCondition(fieldFrom, oper, value);
} else {
// oper.contains( ">" )
return buildCondition(fieldTo, oper, value);
}
} else {
return buildCondition(field, oper, value);
}
}
/**
* Builds a new MCRQueryCondition
*
* @param field
* the name of the search field
* @param oper
* the condition operator
* @param value
* the condition value
* @return
*/
private MCRQueryCondition buildCondition(String field, String oper, String value) {
if ("TODAY".equals(value)) {
value = getToday();
}
return new MCRQueryCondition(field, oper, value);
}
private String getToday() {
GregorianCalendar cal = new GregorianCalendar();
int year = cal.get(Calendar.YEAR);
int month = cal.get(Calendar.MONTH) + 1;
int day = cal.get(Calendar.DAY_OF_MONTH);
return day + "." + month + "." + year;
}
/** Pattern for MCRQueryConditions expressed as String */
private static Pattern pattern = Pattern.compile("([^ \t\r\n]+)\\s+([^ \t\r\n]+)\\s+([^ \"\t\r\n]+|\"[^\"]*\")");
/**
* Parses a String containing a simple query condition, for example: (title
* contains "Java") and (creatorID = "122132131")
*
* @param s
* the condition as a String
* @return the parsed MCRQueryCondition object
*/
@Override
protected MCRCondition parseSimpleCondition(String s) throws MCRParseException {
Matcher m = pattern.matcher(s);
if (!m.find()) {
return super.parseSimpleCondition(s);
}
String field = m.group(1);
String operator = m.group(2);
String value = m.group(3);
if (value.startsWith("\"") && value.endsWith("\"")) {
value = value.substring(1, value.length() - 1);
}
return buildConditions(field, operator, value);
}
@Override
public MCRCondition parse(Element condition) throws MCRParseException {
MCRCondition cond = super.parse(condition);
return normalizeCondition(cond);
}
@Override
public MCRCondition parse(String s) throws MCRParseException {
MCRCondition cond = super.parse(s);
return normalizeCondition(cond);
}
/**
* Normalizes a parsed query condition. AND/OR conditions that just have one
* child will be replaced with that child. NOT(NOT(X)) will be normalized to X.
* (A AND (b AND c)) will be normalized to (A AND B AND C), same for nested ORs.
* AND/OR/NOT conditions with no child conditions will be removed.
* Conditions that use the operator "contains" will be splitted into multiple
* simpler conditions if the condition value contains phrases surrounded
* by '...' or wildcard search with * or ?.
*/
public static MCRCondition normalizeCondition(MCRCondition cond) {
if (cond == null) {
return null;
} else if (cond instanceof MCRSetCondition) {
MCRSetCondition sc = (MCRSetCondition) cond;
List> children = sc.getChildren();
sc = sc instanceof MCRAndCondition ? new MCRAndCondition<>() : new MCROrCondition<>();
for (MCRCondition child : children) {
MCRCondition normalizedChild = normalizeCondition(child);
if (normalizedChild != null) {
if (normalizedChild instanceof MCRSetCondition
&& sc.getOperator().equals(((MCRSetCondition) normalizedChild).getOperator())) {
// Replace (a AND (b AND c)) with (a AND b AND c), same for OR
sc.addAll(((MCRSetCondition) normalizedChild).getChildren());
} else {
sc.addChild(normalizedChild);
}
}
}
children = sc.getChildren();
if (children.size() == 0) {
return null; // Completely remove empty AND condition
} else if (children.size() == 1) {
return children.get(0); // Replace AND with just one child
} else {
return sc;
}
} else if (cond instanceof MCRNotCondition) {
MCRNotCondition nc = (MCRNotCondition) cond;
MCRCondition child = normalizeCondition(nc.getChild());
if (child == null) {
return null; // Remove empty NOT
} else if (child instanceof MCRNotCondition) {
return normalizeCondition(((MCRNotCondition) child).getChild());
} else {
return new MCRNotCondition<>(child);
}
} else if (cond instanceof MCRQueryCondition) {
MCRQueryCondition qc = (MCRQueryCondition) cond;
if (!qc.getOperator().equals("contains")) {
return qc;
}
// Normalize value when contains operator is used
List values = new ArrayList<>();
StringBuilder phrase = null;
StringTokenizer st = new StringTokenizer(qc.getValue(), " ");
while (st.hasMoreTokens()) {
String value = st.nextToken();
if (phrase != null) {
// we are within phrase
if (value.endsWith("'")) {
// end of phrase
value = phrase + " " + value;
values.add(value);
phrase = null;
} else {
// in middle of phrase
phrase.append(' ').append(value);
}
} else if (value.startsWith("'")) {
// begin of phrase
if (value.endsWith("'")) {
// one-word phrase
values.add(value.substring(1, value.length() - 1));
} else {
phrase = new StringBuilder(value);
}
} else if (value.startsWith("-'")) {
// begin of NOT phrase
if (value.endsWith("'")) {
// one-word phrase
values.add("-" + value.substring(2, value.length() - 1));
} else {
phrase = new StringBuilder(value);
}
} else {
values.add(value);
}
}
MCRAndCondition ac = new MCRAndCondition<>();
for (String value : values) {
if (value.startsWith("'")) {
ac.addChild(new MCRQueryCondition(qc.getFieldName(), "phrase", value.substring(1,
value.length() - 1)));
} else if (value.startsWith("-'")) {
ac.addChild(new MCRNotCondition<>(
new MCRQueryCondition(qc.getFieldName(), "phrase", value.substring(2, value.length() - 1))));
} else if (value.contains("*") || value.contains("?")) {
ac.addChild(new MCRQueryCondition(qc.getFieldName(), "like", value));
} else if (value.startsWith("-")) {
// -word means "NOT word"
MCRCondition subCond = new MCRQueryCondition(qc.getFieldName(), "contains",
value.substring(1));
ac.addChild(new MCRNotCondition<>(subCond));
} else {
ac.addChild(new MCRQueryCondition(qc.getFieldName(), "contains", value));
}
}
if (values.size() == 1) {
return ac.getChildren().get(0);
} else {
return ac;
}
} else {
return cond;
}
}
/** Used for input validation in editor search form */
public static boolean validateQueryExpression(String query) {
try {
MCRCondition cond = new MCRQueryParser().parse(query);
return cond != null;
} catch (Throwable t) {
return false;
}
}
}
