org.springframework.util.xml.TransformerUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2019 the original author or authors.
*
* 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
*
* https://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 org.springframework.util.xml;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import org.springframework.util.Assert;
/**
* Contains common behavior relating to {@link javax.xml.transform.Transformer Transformers}
* and the {@code javax.xml.transform} package in general.
*
* @author Rick Evans
* @author Juergen Hoeller
* @since 2.5.5
*/
public abstract class TransformerUtils {
/**
* The indent amount of characters if {@link #enableIndenting indenting is enabled}.
* Defaults to "2".
*/
public static final int DEFAULT_INDENT_AMOUNT = 2;
/**
* Enable indenting for the supplied {@link javax.xml.transform.Transformer}.
*
If the underlying XSLT engine is Xalan, then the special output key {@code indent-amount}
* will be also be set to a value of {@link #DEFAULT_INDENT_AMOUNT} characters.
* @param transformer the target transformer
* @see javax.xml.transform.Transformer#setOutputProperty(String, String)
* @see javax.xml.transform.OutputKeys#INDENT
*/
public static void enableIndenting(Transformer transformer) {
enableIndenting(transformer, DEFAULT_INDENT_AMOUNT);
}
/**
* Enable indenting for the supplied {@link javax.xml.transform.Transformer}.
*
If the underlying XSLT engine is Xalan, then the special output key {@code indent-amount}
* will be also be set to a value of {@link #DEFAULT_INDENT_AMOUNT} characters.
* @param transformer the target transformer
* @param indentAmount the size of the indent (2 characters, 3 characters, etc)
* @see javax.xml.transform.Transformer#setOutputProperty(String, String)
* @see javax.xml.transform.OutputKeys#INDENT
*/
public static void enableIndenting(Transformer transformer, int indentAmount) {
Assert.notNull(transformer, "Transformer must not be null");
if (indentAmount < 0) {
throw new IllegalArgumentException("Invalid indent amount (must not be less than zero): " + indentAmount);
}
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
try {
// Xalan-specific, but this is the most common XSLT engine in any case
transformer.setOutputProperty("{http://xml.apache.org/xalan}indent-amount", String.valueOf(indentAmount));
}
catch (IllegalArgumentException ignored) {
}
}
/**
* Disable indenting for the supplied {@link javax.xml.transform.Transformer}.
* @param transformer the target transformer
* @see javax.xml.transform.OutputKeys#INDENT
*/
public static void disableIndenting(Transformer transformer) {
Assert.notNull(transformer, "Transformer must not be null");
transformer.setOutputProperty(OutputKeys.INDENT, "no");
}
}