com.univocity.parsers.conversions.ObjectConversion Maven / Gradle / Ivy
Show all versions of univocity-parsers Show documentation
/*******************************************************************************
* Copyright 2014 uniVocity Software Pty Ltd
*
* 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.univocity.parsers.conversions;
/**
* Default implementation for conversions from an input String to Objects of a given type T
*
* Extending classes must implement a proper String to T conversion in {@link ObjectConversion#fromString(String)}
*
This abstract class provides default results for conversions when the input is null.
*
It also provides a default implementation of {@link ObjectConversion#revert(Object)} that returns the result of input.toString()
*
* @param The object type resulting from conversions of String values.
*
* @author uniVocity Software Pty Ltd - [email protected]
*/
public abstract class ObjectConversion extends NullConversion {
/**
* Creates a Conversion from String to an Object with default values to return when the input is null.
* The default constructor assumes the output of a conversion should be null when input is null
*/
public ObjectConversion() {
super(null, null);
}
/**
* Creates a Conversion from String to an Object with default values to return when the input is null.
*
* @param valueIfStringIsNull default value of type T to be returned when the input String is null. Used when {@link ObjectConversion#execute(String)} is invoked.
* @param valueIfObjectIsNull default String value to be returned when an input of type T is null. Used when {@link ObjectConversion#revert(Object)} is invoked.
*/
public ObjectConversion(T valueIfStringIsNull, String valueIfObjectIsNull) {
super(valueIfStringIsNull, valueIfObjectIsNull);
}
/**
* Converts the given String to an instance of T
*
* @param input the input String to be converted to an object of type T
*
* @return the conversion result, or the value of {@link ObjectConversion#getValueIfStringIsNull()} if the input String is null.
*/
@Override
public T execute(String input) {
return super.execute(input);
}
/**
* Creates an instance of T from a String representation.
*
* @param input The String to be converted to T
*
* @return an instance of T, converted from the String input.
*/
protected final T fromInput(String input) {
return fromString(input);
}
/**
* Creates an instance of T from a String representation.
*
* @param input The String to be converted to T
*
* @return an instance of T, converted from the String input.
*/
protected abstract T fromString(String input);
/**
* Converts a value of type T back to a String
* This is a general implementation that simply returns the result of input.toString()
*
* @param input the input of type T to be converted to a String
*
* @return the conversion result, or the value of {@link ObjectConversion#getValueIfObjectIsNull()} if the input object is null.
*/
@Override
public String revert(T input) {
return super.revert(input);
}
@Override
protected final String undo(T input) {
return String.valueOf(input);
}
/**
* returns a default value of type T to be returned when the input String is null. Used when {@link ObjectConversion#execute(String)} is invoked.
*
* @return the default value of type T used when converting from a null input
*/
public T getValueIfStringIsNull() {
return getValueOnNullInput();
}
/**
* returns default String value to be returned when an input of type T is null. Used when {@link ObjectConversion#revert(Object)} is invoked.
*
* @return the default String value used when converting from a null input
*/
public String getValueIfObjectIsNull() {
return getValueOnNullOutput();
}
/**
* defines a default value of type T which should be returned when the input String is null. Used when {@link ObjectConversion#execute(String)} is invoked.
*
* @param valueIfStringIsNull the default value of type T when converting from a null input
*/
public void setValueIfStringIsNull(T valueIfStringIsNull) {
setValueOnNullInput(valueIfStringIsNull);
}
/**
* returns default value of type T which should be returned when the input String is null. Used when {@link ObjectConversion#revert(Object)} is invoked.
*
* @param valueIfObjectIsNull a default value of type T when converting from a null input
*/
public void setValueIfObjectIsNull(String valueIfObjectIsNull) {
setValueOnNullOutput(valueIfObjectIsNull);
}
}