| package org.apache.lucene.search; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Objects; |
| |
| /** Expert: Describes the score computation for document and query. */ |
| public final class Explanation { |
| |
| /** |
| * Create a new explanation for a match. |
| * @param value the contribution to the score of the document |
| * @param description how {@code value} was computed |
| * @param details sub explanations that contributed to this explanation |
| */ |
| public static Explanation match(float value, String description, Collection<Explanation> details) { |
| return new Explanation(true, value, description, details); |
| } |
| |
| /** |
| * Create a new explanation for a match. |
| * @param value the contribution to the score of the document |
| * @param description how {@code value} was computed |
| * @param details sub explanations that contributed to this explanation |
| */ |
| public static Explanation match(float value, String description, Explanation... details) { |
| return new Explanation(true, value, description, Arrays.asList(details)); |
| } |
| |
| /** |
| * Create a new explanation for a document which does not match. |
| */ |
| public static Explanation noMatch(String description, Collection<Explanation> details) { |
| return new Explanation(false, 0f, description, details); |
| } |
| |
| /** |
| * Create a new explanation for a document which does not match. |
| */ |
| public static Explanation noMatch(String description, Explanation... details) { |
| return new Explanation(false, 0f, description, Arrays.asList(details)); |
| } |
| |
| private final boolean match; // whether the document matched |
| private final float value; // the value of this node |
| private final String description; // what it represents |
| private final List<Explanation> details; // sub-explanations |
| |
| /** Create a new explanation */ |
| private Explanation(boolean match, float value, String description, Collection<Explanation> details) { |
| this.match = match; |
| this.value = value; |
| this.description = Objects.requireNonNull(description); |
| this.details = Collections.unmodifiableList(new ArrayList<>(details)); |
| for (Explanation detail : details) { |
| Objects.requireNonNull(detail); |
| } |
| } |
| |
| /** |
| * Indicates whether or not this Explanation models a match. |
| */ |
| public boolean isMatch() { |
| return match; |
| } |
| |
| /** The value assigned to this explanation node. */ |
| public float getValue() { return value; } |
| |
| /** A description of this explanation node. */ |
| public String getDescription() { return description; } |
| |
| private String getSummary() { |
| return getValue() + " = " + getDescription(); |
| } |
| |
| /** The sub-nodes of this explanation node. */ |
| public Explanation[] getDetails() { |
| return details.toArray(new Explanation[0]); |
| } |
| |
| /** Render an explanation as text. */ |
| @Override |
| public String toString() { |
| return toString(0); |
| } |
| |
| private String toString(int depth) { |
| StringBuilder buffer = new StringBuilder(); |
| for (int i = 0; i < depth; i++) { |
| buffer.append(" "); |
| } |
| buffer.append(getSummary()); |
| buffer.append("\n"); |
| |
| Explanation[] details = getDetails(); |
| for (int i = 0 ; i < details.length; i++) { |
| buffer.append(details[i].toString(depth+1)); |
| } |
| |
| return buffer.toString(); |
| } |
| |
| |
| /** Render an explanation as HTML. */ |
| public String toHtml() { |
| StringBuilder buffer = new StringBuilder(); |
| buffer.append("<ul>\n"); |
| |
| buffer.append("<li>"); |
| buffer.append(getSummary()); |
| buffer.append("<br />\n"); |
| |
| Explanation[] details = getDetails(); |
| for (int i = 0 ; i < details.length; i++) { |
| buffer.append(details[i].toHtml()); |
| } |
| |
| buffer.append("</li>\n"); |
| buffer.append("</ul>\n"); |
| |
| return buffer.toString(); |
| } |
| } |