001/* 002 * Copyright 2012-2017 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.boot.autoconfigure.mustache; 018 019import com.samskivert.mustache.DefaultCollector; 020import com.samskivert.mustache.Mustache.Collector; 021import com.samskivert.mustache.Mustache.VariableFetcher; 022 023import org.springframework.context.EnvironmentAware; 024import org.springframework.core.env.ConfigurableEnvironment; 025import org.springframework.core.env.Environment; 026 027/** 028 * Mustache {@link Collector} to expose properties from the Spring {@link Environment}. 029 * 030 * @author Dave Syer 031 * @author Madhura Bhave 032 * @since 1.2.2 033 */ 034public class MustacheEnvironmentCollector extends DefaultCollector 035 implements EnvironmentAware { 036 037 private ConfigurableEnvironment environment; 038 039 private final VariableFetcher propertyFetcher = new PropertyVariableFetcher(); 040 041 @Override 042 public void setEnvironment(Environment environment) { 043 this.environment = (ConfigurableEnvironment) environment; 044 } 045 046 @Override 047 public VariableFetcher createFetcher(Object ctx, String name) { 048 VariableFetcher fetcher = super.createFetcher(ctx, name); 049 if (fetcher != null) { 050 return fetcher; 051 } 052 if (this.environment.containsProperty(name)) { 053 return this.propertyFetcher; 054 } 055 return null; 056 } 057 058 private class PropertyVariableFetcher implements VariableFetcher { 059 060 @Override 061 public Object get(Object ctx, String name) throws Exception { 062 return MustacheEnvironmentCollector.this.environment.getProperty(name); 063 } 064 065 } 066 067}