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Generic support library for web applications.
/*
* Copyright (c) 2017, Numdata BV, The Netherlands.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Numdata nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL NUMDATA BV BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.numdata.oss.web.form;
import java.lang.reflect.*;
import java.math.*;
import java.net.*;
import java.sql.*;
import java.util.*;
import java.util.Date;
import java.util.regex.*;
import com.numdata.oss.*;
import org.jetbrains.annotations.*;
/**
* Target type: reflected. Value is a field/property of the target object
* accessible through reflection. The field may be a class field, or a property
* accessible using getter and setter methods.
*
* @author G.B.M. Rupert
*/
public class ReflectedFieldTarget
implements FieldTarget
{
/**
* Name of object property or field.
*/
private final String _propertyName;
/**
* Name of form field.
*/
private final String _fieldName;
/**
* Target object.
*/
private final Object _target;
/**
* Class field used for a reflection target with direct (public) access to
* the field. This supersedes the getter/setter method.
*/
private final Field _field;
/**
* Class method used for a reflection target with getter/setter access to
* the field. This is the getter method.
*/
private final Method _getter;
/**
* Construct new reflected field target.
*
* @param target Target object.
* @param name Name of field .
*/
public ReflectedFieldTarget( final Object target, final String name )
{
this( target, name, name );
}
/**
* Construct new reflected field target.
*
* @param target Target object.
* @param propertyName Name of object property or field.
* @param fieldName Name of form field.
*/
public ReflectedFieldTarget( final Object target, final String propertyName, final String fieldName )
{
_propertyName = propertyName;
_fieldName = fieldName;
/*
* Try reflection to public field.
*/
final Class targetClass = target.getClass();
Field field;
try
{
field = targetClass.getField( propertyName );
}
catch ( final NoSuchFieldException ignored )
{
field = null;
/* Ignore. */
}
/*
* Use reflection to get getter method.
*/
Method getter = null;
if ( field == null )
{
getter = getAccessor( targetClass, "get", propertyName, null );
if ( getter == null )
{
getter = getAccessor( targetClass, "is", propertyName, null );
}
if ( getter == null )
{
getter = getAccessor( targetClass, "has", propertyName, null );
}
if ( getter == null )
{
throw new IllegalArgumentException( "Illegal target '" + target + "' for field '" + propertyName + '\'' );
}
}
_target = target;
_field = field;
_getter = getter;
}
@Override
@NotNull
public String getName()
{
return _fieldName;
}
@Override
@Nullable
public String getValue()
{
try
{
final Object value;
if ( _field != null )
{
value = _field.get( _target );
}
else
{
value = _getter.invoke( _target );
}
return toString( value );
}
catch ( final IllegalAccessException e )
{
throw new RuntimeException( "Access denied to accessor method while getting '" + getName() + '\'', e );
}
catch ( final InvocationTargetException e )
{
throw new RuntimeException( "Exception encountered while getting '" + getName() + '\'', e );
}
}
@Override
public void setValue( @Nullable final String value )
{
final Object target = _target;
final Field field = _field;
final Method getter = _getter;
try
{
if ( field != null )
{
field.set( target, parse( value ) );
}
else if ( getter != null )
{
final Method setter = getAccessor( target.getClass(), "set", _propertyName, _getter.getReturnType() );
if ( setter == null )
{
throw new RuntimeException( "property '" + _propertyName + "' is read-only" );
}
setter.invoke( target, parse( value ) );
}
else
{
throw new RuntimeException( "no field or getter defined" );
}
}
catch ( final InvocationTargetException e )
{
throw new RuntimeException( "Exception encountered while setting '" + getName() + "' to " + TextTools.quote( value ), e );
}
catch ( final IllegalAccessException e )
{
throw new RuntimeException( "Access denied to accessor method while setting '" + getName() + "' to " + TextTools.quote( value ), e );
}
}
/**
* Get accessor method for the specified property.
*
* @param aClass Class to get the method from.
* @param prefix Name prefix of method (e.g. "get", "set", "is").
* @param property Property name (e.g. "value").
* @param type Argument type ({@code null} for none).
*
* @return Accessor method; {@code null} if the specified method was not
* found.
*/
@Nullable
private static Method getAccessor( final Class aClass, final String prefix, final String property, @Nullable final Class type )
{
final String name = prefix + Character.toUpperCase( property.charAt( 0 ) ) + property.substring( 1 );
@SuppressWarnings( "rawtypes" ) final Class[] args = ( type == null ) ? new Class[] {} : new Class[] { type };
Method result;
try
{
result = aClass.getMethod( name, args );
}
catch ( final Exception ignored )
{
result = null;
}
return result;
}
/**
* Convert value to string.
*
* @param value Value to convert.
*
* @return String representation of value.
*/
@Nullable
public static String toString( final Object value )
{
final String result;
if ( value instanceof Calendar )
{
result = Long.toString( ( (Calendar)value ).getTime().getTime() );
}
else if ( value instanceof Date )
{
result = Long.toString( ( (Date)value ).getTime() );
}
else if ( value instanceof BigDecimal )
{
result = ( (BigDecimal)value ).toPlainString();
}
else if ( value instanceof Pattern )
{
result = ( (Pattern)value ).pattern();
}
else
{
result = ( value != null ) ? String.valueOf( value ) : null;
}
return result;
}
/**
* Check type and perform necessary type conversion. {@code null} is always
* accepted.
*
* @param value Value to check.
*
* @return Possibly type-converted value.
*
* @throws IllegalArgumentException if the value does not match the field
* type.
*/
@Nullable
@SuppressWarnings( "ObjectEquality" )
protected Object parse( @Nullable final String value )
{
Object result = value;
final Class type = ( _field != null ) ? _field.getType() : _getter.getReturnType();
if ( ( value != null ) && ( type != String.class ) )
{
/**/
if ( type == Boolean.class )
{
result = TextTools.isEmpty( value ) ? null : Boolean.valueOf( value );
}
else if ( type == BigDecimal.class )
{
result = TextTools.isEmpty( value ) ? null : new BigDecimal( value );
}
else if ( type == BigInteger.class )
{
result = TextTools.isEmpty( value ) ? null : new BigInteger( value );
}
else if ( type == boolean.class )
{
result = Boolean.valueOf( value );
}
else if ( type == Byte.class )
{
result = TextTools.isEmpty( value ) ? null : new Byte( value );
}
else if ( type == byte.class )
{
result = new Byte( value );
}
else if ( type == Short.class )
{
result = TextTools.isEmpty( value ) ? null : new Short( value );
}
else if ( type == short.class )
{
result = new Short( value );
}
else if ( type == Character.class )
{
result = TextTools.isEmpty( value ) ? null : Character.valueOf( value.charAt( 0 ) );
}
else if ( type == char.class )
{
result = new Character( !value.isEmpty() ? value.charAt( 0 ) : '\0' );
}
else if ( type == Integer.class )
{
result = TextTools.isEmpty( value ) ? null : new Integer( value );
}
else if ( type == int.class )
{
result = Integer.valueOf( value );
}
else if ( type == Long.class )
{
result = TextTools.isEmpty( value ) ? null : new Long( value );
}
else if ( type == long.class )
{
result = new Long( value );
}
else if ( type == Float.class )
{
result = TextTools.isEmpty( value ) ? null : new Float( value );
}
else if ( type == float.class )
{
result = new Float( value );
}
else if ( type == Double.class )
{
result = TextTools.isEmpty( value ) ? null : new Double( value );
}
else if ( type == double.class )
{
result = new Double( value );
}
else if ( type == Calendar.class )
{
result = TextTools.isEmpty( value ) ? null : CalendarTools.getInstance( new Date( Long.parseLong( value ) ) );
}
else if ( type == Currency.class )
{
result = TextTools.isEmpty( value ) ? null : Currency.getInstance( value.trim() );
}
else if ( type == Date.class )
{
result = TextTools.isEmpty( value ) ? null : new Date( Long.parseLong( value ) );
}
else if ( type == Time.class )
{
result = TextTools.isEmpty( value ) ? null : new Time( Long.parseLong( value ) );
}
else if ( type == Locale.class )
{
result = TextTools.isEmpty( value ) ? null : LocaleTools.parseLocale( value );
}
else if ( type == Pattern.class )
{
result = TextTools.isEmpty( value ) ? null : Pattern.compile( value );
}
else if ( type == URL.class )
{
try
{
result = TextTools.isEmpty( value ) ? null : new URL( value );
}
catch ( final MalformedURLException e )
{
throw new IllegalArgumentException( "Malformed '" + getName() + "' URL: " + value, e );
}
}
else if ( type.isEnum() )
{
//noinspection rawtypes
result = TextTools.isEmpty( value ) ? null : Enum.valueOf( (Class)type, value );
}
else
{
throw new IllegalArgumentException( "Don't know how to convert '" + getName() + "' java.lang.String value to " + type );
}
}
return result;
}
}
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