com.phloc.commons.format.impl.AbstractStringFormatter Maven / Gradle / Ivy
/**
* Copyright (C) 2006-2014 phloc systems
* http://www.phloc.com
* office[at]phloc[dot]com
*
* 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.phloc.commons.format.impl;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import com.phloc.commons.annotations.OverrideOnDemand;
import com.phloc.commons.format.IFormatter;
import com.phloc.commons.string.ToStringGenerator;
import com.phloc.commons.typeconvert.TypeConverter;
/**
* Base implementation class of the {@link IFormatter} interface that provides
* the common functionality.
*
* @author Philip Helger
*/
public abstract class AbstractStringFormatter implements IFormatter
{
private final IFormatter m_aPrevFormatter;
/**
* Default constructor
*/
public AbstractStringFormatter ()
{
this (null);
}
/**
* @param aPrevFormatter
* Optional previous formatter to be invoked, before this formatter is
* invoked. May be null
.
*/
public AbstractStringFormatter (@Nullable final IFormatter aPrevFormatter)
{
m_aPrevFormatter = aPrevFormatter;
}
/**
* Convert the source value to a string by using the {@link TypeConverter}.
*
* @param aValue
* The value to be converted to a string
* @return The string representation of the object and never null
* .
*/
@OverrideOnDemand
@Nonnull
protected String getValueAsString (@Nullable final Object aValue)
{
final String sValue = TypeConverter.convertIfNecessary (aValue, String.class);
return sValue != null ? sValue : "";
}
/**
* Convert the passed value from Object to formatted String. Use
* {@link #getValueAsString(Object)} in implementations of this method to do
* the base conversion from Object to String.
*
* @param aValue
* The source object. May be null
.
* @return The formatted string value.
*/
@Nullable
protected abstract String getFormattedValueAsString (@Nullable Object aValue);
@Nullable
public final String getFormattedValue (@Nullable final Object aValue)
{
// Invoked any nested previous formatter
final Object aBase = m_aPrevFormatter == null ? aValue : m_aPrevFormatter.getFormattedValue (aValue);
return getFormattedValueAsString (aBase);
}
@Override
public String toString ()
{
return new ToStringGenerator (this).appendIfNotNull ("prevFormatter", m_aPrevFormatter).toString ();
}
}