Java Simple XML Converter将元素写入OutputNode

Question

简单的XML允许您制作自己的转换器.

此write方法用于将对象序列化为XML.应该以这样的方式执行序列化:所有对象值由所提供节点的元素或属性表示.这确保了它可以在以后完全反序列化.

@Convert(MyClass.Converter.class)
public class MyClass {
  public MyClass() {}

  public static class Converter implements Converter<MyClass> {
    public MyClass read(InputNode node) {
      return new MyClass();
    }

    public void write(OutputNode node, MyClass value) {

    }
  }
}

该文档描述了在OutputNode中表示元素,那么如何向OutputNode添加元素？OutputNode的文档似乎没有任何方法可以向其添加元素或节点.

Answer 1

您既可以手动添加元素,Serializer也可以使用其他元素添加元素- Serializer也可以向/从节点写入/读取.

这是一个例子:

@Root(name = "MyClass") // @Root required
@Convert(MyClass.MyClassConverter.class)
public class MyClass
{
    private int value;
    private String name;

    /* Ctor, getter, setter etc. */


    public static class MyClassConverter implements Converter<MyClass>
    {
        @Override
        public MyClass read(InputNode node) throws Exception
        {
            MyClass mc = new MyClass();

            /* Read the (int) value of 'someValue' node */
            int value = Integer.parseInt(node.getNext("someValue").getValue());
            mc.setValue(value);

            /* Same for the string */
            String name = node.getNext("someString_" + value).getValue();
            mc.setName(name);

            /* Do something with data not used in MyClass, but useable anyway */
            if( node.getNext("from") == null )
            {
                throw new IllegalArgumentException("Node 'from' is missing!");
            }

            return mc;
        }


        @Override
        public void write(OutputNode node, MyClass value) throws Exception
        {
            /* Add an attribute to the root node */
            node.setAttribute("example", "true");

            OutputNode valueNode = node.getChild("someValue");      // Create a child node ...
            valueNode.setAttribute("stack", "overflow");            // ... with an attribute
            valueNode.setValue(String.valueOf(value.getValue()));   // ... and a value

            /*
             * Converter allow a dynamic creation -- here the node names is
             * created from two values of MyClass
             */
            node.getChild("someString_" + value.getValue())     // Create another child node ...
                    .setValue(value.getName());                 // ... with a value only

            /* Create another node from scratch */
            OutputNode fromNode = node.getChild("from");
            fromNode.setValue("scratch");
            fromNode.setComment("This node is created by the converter");
        }

    }

}

要写/读的xml:

<MyClass example="true">
   <someValue stack="overflow">27</someValue>
   <someString_27>abc</someString_27>
   <!-- This node is created by the converter -->
   <from>scratch</from>
</MyClass>

重要提示:您必须使用AnnotationStrategy,否则将@Convert无法工作.

Serializer ser = new Persister(new AnnotationStrategy())
ser.write(...);