Java tutorial
/** Copyright (c) 2007-2013 Alysson Bessani, Eduardo Alchieri, Paulo Sousa, and the authors indicated in the @author tags 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 bftsmart.consensus; import java.io.Externalizable; import java.io.IOException; import java.io.ObjectInput; import java.io.ObjectOutput; import java.math.BigInteger; import java.util.Arrays; import org.apache.commons.codec.binary.Base64; /** * This class associates a timestamp to a value * * @author Joao Sousa */ public class TimestampValuePair implements Externalizable { private int timestamp; // timestamp private byte[] value; // value private byte[] hashedValue; // hash of the value /** * Constructor * @param timestamp Timestamp * @param value Value */ public TimestampValuePair(int timestamp, byte[] value) { this.timestamp = timestamp; this.value = value; this.hashedValue = new byte[0]; } /** * Empty construtor */ public TimestampValuePair() { this.timestamp = -1; this.value = new byte[0]; this.hashedValue = new byte[0]; } /** * Set the value's hash * @param hashedValue Sintese do valor */ public void setHashedValue(byte[] hashedValue) { this.hashedValue = hashedValue; } /** * Get the value's hash * @return hash of the value */ public byte[] getHashedValue() { return hashedValue; } /** * Get timestamp * @return The timestamp */ public int getTimestamp() { return timestamp; } /** * Get value * @return Value */ public byte[] getValue() { return value; } @Override public boolean equals(Object o) { if (o instanceof TimestampValuePair) { return ((TimestampValuePair) o).timestamp == timestamp && Arrays.equals(((TimestampValuePair) o).value, value); } return false; } @Override public int hashCode() { int hash = 1; hash = hash * 17 + timestamp; hash = hash * 31 + (new BigInteger(value)).intValue(); return hash; } public String toString() { if (this.value == null || this.value.length == 0) return timestamp + " :: []"; else return timestamp + " :: " + (this.hashedValue != null && this.hashedValue.length > 0 ? str(this.hashedValue) : str(value)); } @Override public void writeExternal(ObjectOutput out) throws IOException { out.writeInt(timestamp); out.writeObject(value); } @Override public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException { timestamp = in.readInt(); value = (byte[]) in.readObject(); } private String str(byte[] obj) { if (obj == null) { return "null"; } else { return Base64.encodeBase64String(obj); } } }