| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.solr.handler.dataimport; |
| |
| import static org.apache.solr.handler.dataimport.DataImportHandlerException.SEVERE; |
| import static org.apache.solr.handler.dataimport.DataImportHandlerException.wrapAndThrow; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.regex.Pattern; |
| |
| /** |
| * <p> |
| * Pluggable functions for resolving variables |
| * </p> |
| * <p> |
| * Implementations of this abstract class must provide a public no-arg constructor. |
| * </p> |
| * <p> |
| * Refer to <a |
| * href="http://wiki.apache.org/solr/DataImportHandler">http://wiki.apache.org/solr/DataImportHandler</a> |
| * for more details. |
| * </p> |
| * <b>This API is experimental and may change in the future.</b> |
| * |
| * @since solr 1.3 |
| */ |
| public abstract class Evaluator { |
| |
| /** |
| * Return a String after processing an expression and a {@link VariableResolver} |
| * |
| * @see VariableResolver |
| * @param expression string to be evaluated |
| * @param context instance |
| * @return the value of the given expression evaluated using the resolver |
| */ |
| public abstract String evaluate(String expression, Context context); |
| |
| /** |
| * Parses a string of expression into separate params. The values are separated by commas. each value will be |
| * translated into one of the following: |
| * <ol> |
| * <li>If it is in single quotes the value will be translated to a String</li> |
| * <li>If is is not in quotes and is a number a it will be translated into a Double</li> |
| * <li>else it is a variable which can be resolved and it will be put in as an instance of VariableWrapper</li> |
| * </ol> |
| * |
| * @param expression the expression to be parsed |
| * @param vr the VariableResolver instance for resolving variables |
| * |
| * @return a List of objects which can either be a string, number or a variable wrapper |
| */ |
| protected List<Object> parseParams(String expression, VariableResolver vr) { |
| List<Object> result = new ArrayList<>(); |
| expression = expression.trim(); |
| String[] ss = expression.split(","); |
| for (int i = 0; i < ss.length; i++) { |
| ss[i] = ss[i].trim(); |
| if (ss[i].startsWith("'")) {//a string param has started |
| StringBuilder sb = new StringBuilder(); |
| while (true) { |
| sb.append(ss[i]); |
| if (ss[i].endsWith("'")) break; |
| i++; |
| if (i >= ss.length) |
| throw new DataImportHandlerException(SEVERE, "invalid string at " + ss[i - 1] + " in function params: " + expression); |
| sb.append(","); |
| } |
| String s = sb.substring(1, sb.length() - 1); |
| s = s.replaceAll("\\\\'", "'"); |
| result.add(s); |
| } else { |
| if (Character.isDigit(ss[i].charAt(0))) { |
| try { |
| Double doub = Double.parseDouble(ss[i]); |
| result.add(doub); |
| } catch (NumberFormatException e) { |
| if (vr.resolve(ss[i]) == null) { |
| wrapAndThrow( |
| SEVERE, e, "Invalid number :" + ss[i] + |
| "in parameters " + expression); |
| } |
| } |
| } else { |
| result.add(getVariableWrapper(ss[i], vr)); |
| } |
| } |
| } |
| return result; |
| } |
| |
| protected VariableWrapper getVariableWrapper(String s, VariableResolver vr) { |
| return new VariableWrapper(s,vr); |
| } |
| |
| static protected class VariableWrapper { |
| public final String varName; |
| public final VariableResolver vr; |
| |
| public VariableWrapper(String s, VariableResolver vr) { |
| this.varName = s; |
| this.vr = vr; |
| } |
| |
| public Object resolve() { |
| return vr.resolve(varName); |
| } |
| |
| @Override |
| public String toString() { |
| Object o = vr.resolve(varName); |
| return o == null ? null : o.toString(); |
| } |
| } |
| |
| static Pattern IN_SINGLE_QUOTES = Pattern.compile("^'(.*?)'$"); |
| |
| public static final String DATE_FORMAT_EVALUATOR = "formatDate"; |
| |
| public static final String URL_ENCODE_EVALUATOR = "encodeUrl"; |
| |
| public static final String ESCAPE_SOLR_QUERY_CHARS = "escapeQueryChars"; |
| |
| public static final String SQL_ESCAPE_EVALUATOR = "escapeSql"; |
| } |