Java tutorial
/* This file is part of Cyclos (www.cyclos.org). A project of the Social Trade Organisation (www.socialtrade.org). Cyclos is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. Cyclos is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Cyclos; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package nl.strohalm.cyclos.utils; import java.io.Serializable; import java.math.BigDecimal; import java.math.MathContext; import nl.strohalm.cyclos.entities.settings.LocalSettings; import org.apache.commons.lang.builder.EqualsBuilder; import org.apache.commons.lang.builder.HashCodeBuilder; /** * Represents a percentage or fixed value * @author luis */ public class Amount implements Serializable, Cloneable { public static enum Type implements StringValuedEnum { PERCENTAGE("P"), FIXED("F"); public static Type getFromValue(final String value) { for (final Type type : values()) { if (type.getValue().equals(value)) { return type; } } return null; } private final String value; private Type(final String value) { this.value = value; } // TODO JAVADOC public BigDecimal apply(final BigDecimal number, final BigDecimal amount) { if (number == null || amount == null) { return number; } final MathContext mathContext = new MathContext(LocalSettings.BIG_DECIMAL_DIVISION_PRECISION); if (this == FIXED) { return amount; } else { return (number.multiply(amount).divide(new BigDecimal(100), mathContext)); } } public String getValue() { return value; } } private static final long serialVersionUID = 6344417251664586114L; public static Amount fixed(final BigDecimal value) { final Amount amount = new Amount(); amount.setType(Type.FIXED); amount.setValue(value); return amount; } public static Amount percentage(final BigDecimal value) { final Amount amount = new Amount(); amount.setType(Type.PERCENTAGE); amount.setValue(value); return amount; } private Type type; private BigDecimal value; public Amount() { } public Amount(final BigDecimal value, final Type type) { this.value = value; this.type = type; } // TODO JAVADOC public BigDecimal add(final BigDecimal number) { final BigDecimal applied = apply(number); if (applied == null) { return null; } return applied.add(number); } // TODO JAVADOC public BigDecimal apply(final BigDecimal number) { if (value == null || type == null || number == null) { return number; } return type.apply(number, value); } @Override public Amount clone() { try { return (Amount) super.clone(); } catch (final CloneNotSupportedException e) { return null; } } @Override public boolean equals(final Object obj) { if (!(obj instanceof Amount)) { return false; } final Amount amount = (Amount) obj; return new EqualsBuilder().append(value, amount.value).append(type, amount.type).isEquals(); } public Type getType() { return type; } public BigDecimal getValue() { return value; } @Override public int hashCode() { return new HashCodeBuilder().append(value).append(type).toHashCode(); } public boolean isPercentage() { return type == Type.PERCENTAGE; } public void setType(final Type type) { this.type = type; } public void setValue(final BigDecimal value) { this.value = value; } @Override public String toString() { return value + (type == Type.PERCENTAGE ? "%" : ""); } }