Table of Contents
If your project uses Maven 2, it is fairly easy to add Axiom to your project.
Simply add the following entries to the
<dependency> <groupId>org.apache.ws.commons.axiom</groupId> <artifactId>axiom-api</artifactId> <version>1.2.21</version> </dependency> <dependency> <groupId>org.apache.ws.commons.axiom</groupId> <artifactId>axiom-impl</artifactId> <version>1.2.21</version> <scope>runtime</scope> </dependency>
All Axiom releases are deployed to the Maven central repository and there is no need
to add an entry to the
However, if you want to work with the development (snapshot) version of Axiom, it
is necessary to add the Apache Snapshot Repository:
<repository> <id>apache.snapshots</id> <name>Apache Snapshot Repository</name> <url>http://repository.apache.org/snapshots/</url> <releases> <enabled>false</enabled> </releases> </repository>
If you are working on another Apache project, you don't need to add the snapshot repository
in the POM file since it is already declared in the
Axiom requires the Java Activation Framework (JAF) to work. There are two commonly used incarnations of this library: one is Sun's reference implementation, the other is part of the Geronimo project. Axiom declares a dependency on the Geronimo version. If your project uses another library that depends on JAF, but that refers to Sun's implementation, your project will end up with dependencies on two different artifacts implementing the same API.
If you prefer Sun's implementations, then you should change the declaration of the Axiom dependencies in your POM file as follow:
<dependency> <groupId>org.apache.ws.commons.axiom</groupId> <artifactId>axiom-
xxx</artifactId> <version>1.2.21</version> <exclusions> <exclusion> <groupId>org.apache.geronimo.specs</groupId> <artifactId>geronimo-activation_1.1_spec</artifactId> </exclusion> </exclusions> </dependency>
If you prefer Geronimo's implementation, then you need to identify the libraries
depending on Sun's artifact (
and add the relevant exclusions. You can use
mvn dependency:tree to easily identify where a transitive dependency
Sometimes it is necessary to customize some particular aspects of Axiom for an entire application. There are several things that can be configured through system properties and/or property files. This is also important when using third party applications or libraries that depend on Axiom.
The information in this section only applies to
The feature described in this section was introduced in Axiom 1.2.9.
When creating a new
looks for a property file named
XMLOutputFactory.properties) in the classpath,
using the same class loader as the one from which the factory is loaded
(by default this is the context classloader).
If a corresponding resource is found, the properties in that file
are applied to the factory using the
This feature can be used to set factory properties of type
String. The following
sections present some sample use cases.
Section 2.11 of [XML] specifies that an “XML processor must behave as if it normalized all line breaks in external parsed entities (including the document entity) on input, before parsing, by translating both the two-character sequence #xD #xA and any #xD that is not followed by #xA to a single #xA character.” This implies that when a Windows style line ending, i.e. a CR-LF character sequence is serialized literally into an XML document, the CR character will be lost during deserialization. Depending on the use case this may or may not be desirable.
The only way to strictly preserve CR characters is to serialize them as
character entities, i.e.
. This is the default
behavior of Woodstox. This can be easily checked using the following Java snippet:
OMFactory factory = OMAbstractFactory.getOMFactory(); OMElement element = factory.createOMElement("root", null); element.setText("Test\r\nwith CRLF"); element.serialize(System.out);
This code produces the following output:
From Axiom's point of view this is actually a reasonable behavior.
The reason is that when creating an
In some cases this behavior may be undesirable. Fortunately Woodstox allows to modify this behavior
by changing the value of the
XMLOutputFactory. If Axiom is used (and in particular
StAXUtils) than this can be achieved by adding
XMLOutputFactory.properties file with the following content
to the classpath (in the default package):
Now the output of the Java snippet shown above will be:
<root>Test with CRLF</root>
StAXUtils creates StAX parsers in coaelescing mode.
In this mode, the parser will never return two character data events in sequence, while
in non coaelescing mode, the parser is allowed to break up character data into smaller
chunks and to return multiple consecutive character events, which may improve throughput
for documents containing large text nodes.
It should be noted that
StAXUtils overrides the default settings
mandated by the StAX specification, which specifies that by default, a StAX parser must
be in non coalescing mode. The primary reason is compatibility: older versions of
Woodstox had coalescing switched on by default.
A side effect of the default settings chosen by Axiom is that by default, CDATA sections
are not reported by parser created by
StAXUtils. The reason is that in coalescing mode, the parser will
not only coaelsce adjacent text nodes, but also CDATA sections. Applications that require
correct reporting of CDATA sections should therefore disable coalescing. This can be
achieved by creating a
XMLInputFactory.properties file with the
The release notes provide information about changes in Axiom that might impact existing code when migrating from an older version of Axiom. Note that they are not meant as a change log that lists all changes or new features. Also, before upgrading to a newer Axiom version, you should always check if your code uses methods or classes that have been deprecated. You should fix all deprecation warnings before changing the Axiom version. In general the Javadoc of the deprecated class or method gives you a hint on how to change your code.