Java tutorial
/* * Copyright 2016 Netflix, Inc. * * Licensed 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 com.netflix.ndbench.core.config; import com.google.common.base.Preconditions; import com.google.common.collect.Maps; import com.netflix.ndbench.core.util.NdBenchConstants; import org.apache.commons.lang.StringUtils; import java.util.Map; import java.util.Properties; /** * Loads {@link System#getProperties()} as a source. * <p/> * Implementation note: {@link #set(String, String)} does not write to system properties, but will write to a new map. * This means that setting values to this source has no effect on system properties or other instances of this class. */ public final class SystemPropertiesConfigSource extends AbstractConfigSource { private final Map<String, String> data = Maps.newConcurrentMap(); @Override public void initialize() { super.initialize(); Properties systemProps = System.getProperties(); for (final String key : systemProps.stringPropertyNames()) { if (!key.startsWith(NdBenchConstants.WEBAPP_NAME)) { continue; } final String value = systemProps.getProperty(key); if (!StringUtils.isEmpty(value)) { data.put(key, value); } } } @Override public int size() { return data.size(); } @Override public String get(final String key) { return data.get(key); } @Override public void set(final String key, final String value) { Preconditions.checkNotNull(value, "Value can not be null for configurations"); data.put(key, value); } }