JarCastingXmlConfigMapper
What is XmlConfigMapper?
XmlConfigMapper uses annotation processing to generate the XML-based config file parser for java model classes (POJO). This is not a standard XML deserializer. Its aim is reducing code as much as possible when you want to read something from XML as config files.
Requirements
XmlConfigMapper requires Java 1.8 or later.
How to use
Maven
For Maven-based projects, add the following to your POM file in order to use XmlConfigMapper:
<properties>
<xmlconfigmapper.version>0.2.0</xmlconfigmapper.version>
</properties>
<dependencies>
<dependency>
<groupId>com.github.shootmoon</groupId>
<artifactId>xmlconfigmapper-core</artifactId>
<version>${xmlconfigmapper.version}</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<annotationProcessorPaths>
<path>
<groupId>com.github.shootmoon</groupId>
<artifactId>xmlconfigmapper-processor</artifactId>
<version>${xmlconfigmapper.version}</version>
</path>
</annotationProcessorPaths>
</configuration>
</plugin>
</plugins>
</build>
Gradle
For Gradle, you need something along the following lines:
plugins {
id "net.ltgt.apt" version "0.21"
}
dependencies {
compile 'com.github.shootmoon:xmlconfigmapper-core:0.2.0'
annotationProcessor 'com.github.shootmoon:xmlconfigmapper-processor:0.2.0'
testAnnotationProcessor 'com.github.shootmoon:xmlconfigmapper-processor:0.2.0' // if you are using XmlConfigMapper in test code
}
Mark a class as model class
To mark a class as deserializeable by XmlConfigMapper you have to annotate your model class with @XmlConfigBean.
@XmlConfigBean(name = "book") // name is optional. Per default we use class name in lowercase
public class Book {
String title;
}
Property field
Reading the following XML(attribute is not supported):
<root>
<book>
<id>1</id>
</book>
</root>
@XmlConfigBean
public class Book {
String id;
}
Per default the field name will be used as name, but you can customize field within the @Property(name = "id") annotation,
Type Converter
Property field can read String, Integer, Boolean, Long, Double, LocalDateTime. You can also specify your own type converter that takes the xml text content as input and convert it to the desired type:
<root>
<book>
<id>123</id>
<publish_date>2015-11-25</publish_date>
</book>
</root>
@XmlConfigBean
public class Book {
String id;
@Property(name = "publish_date", converter = MyDateConverter.class)
Date published;
}
public class MyDateConverter implements TypeConverter<Date> {
private SimpleDateFormat formatter = new SimpleDateFormat("yyyy.MM.dd"); // SimpleDateFormat is not thread safe!
@Override
public Date read(String value) {
return formatter.parse(value);
}
}
Your custom TypeConverter must provide an empty (parameter less) constructor).
Element field
In XML you can nest child elements in element:
<root>
<store>
<book>
<id>1</id>
</book>
<book>
<id>2</id>
</book>
<book>
<id>3</id>
</book>
</store>
</root>
@XmlConfigBean
public class Book {
String id;
}
@XmlConfigBean
public class Store {
List<Book> books;
}
XmlConfigMapper will parse instances of Book automatically for you.
Path
Sometimes you maybe want to put nest child elements under a specific element like this:
<root>
<store>
<books>
<book>
<id>1</id>
</book>
<book>
<id>2</id>
</book>
<book>
<id>3</id>
</book>
</books>
</store>
</root>
To parse that into java classes we would have to add a Books class. This isn't really memory efficient because we have to instantiate Books to access <book>. With @Path we can emulate this XML nodes:
@XmlConfigBean
public class Store {
@Path("books")
List<Book> books;
}
XmlConfigMapper will read <book> without the extra cost of allocating such an object.
The mapper interface
To generate a mapper for reading Store object, a mapper interface needs to be defined:
@XmlConfigMapper
public interface StoreMapper {
MyMapper INSTANCE = XmlConfigMappers.getMapper(MyMapper.class);
@XmlConfigMapping
List<Store> getStoreList(String filePath);
//or just first element
@XmlConfigMapping
Store getStore(String filePath);
}