001package org.apache.maven.enforcer.rule.api; 002 003/* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022import javax.annotation.Nonnull; 023import javax.annotation.Nullable; 024 025/** 026 * Interface to be implemented by any rules executed by the enforcer. 027 * 028 * @author <a href="mailto:brianf@apache.org">Brian Fox</a> 029 * @version $Id: EnforcerRule.java 1663790 2015-03-03 21:07:38Z khmarbaise $ 030 */ 031public interface EnforcerRule 032{ 033 034 /** 035 * This is the interface into the rule. This method should throw an exception 036 * containing a reason message if the rule fails the check. The plugin will 037 * then decide based on the fail flag if it should stop or just log the 038 * message as a warning. 039 * 040 * @param helper The helper provides access to the log, MavenSession and has 041 * helpers to get common components. It is also able to lookup components 042 * by class name. 043 * 044 * @throws EnforcerRuleException the enforcer rule exception 045 */ 046 void execute( @Nonnull EnforcerRuleHelper helper ) 047 throws EnforcerRuleException; 048 049 /** 050 * This method tells the enforcer if the rule results may be cached. If the result is true, 051 * the results will be remembered for future executions in the same build (ie children). Subsequent 052 * iterations of the rule will be queried to see if they are also cacheable. This will allow the rule to be 053 * uncached further down the tree if needed. 054 * 055 * @return <code>true</code> if rule is cacheable 056 */ 057 boolean isCacheable(); 058 059 /** 060 * Checks if cached result is valid. 061 * 062 * @param cachedRule the last cached instance of the rule. This is to be used by the rule to 063 * potentially determine if the results are still valid (ie if the configuration has been overridden) 064 * 065 * @return <code>true</code> if the stored results are valid for the same id. 066 */ 067 boolean isResultValid( @Nonnull EnforcerRule cachedRule ); 068 069 /** 070 * If the rule is to be cached, this id is used as part of the key. This can allow rules to take parameters 071 * that allow multiple results of the same rule to be cached. 072 * 073 * @return id to be used by the enforcer to determine uniqueness of cache results. The ids only need to be unique 074 * within a given rule implementation as the full key will be [classname]-[id] 075 */ 076 @Nullable 077 String getCacheId(); 078 079}