如何从对象层次结构生成xml？

I have object, tree/model/hierarchy, whatever the correct term is. It consists of what could be characterized as a one-to-one mapping of the desired XML.

我有对象,树/模型/层次结构,无论正确的术语是什么。它由可以表征为所需XML的一对一映射的内容组成。

That is i have the following (in a non-standard UML sort of syntax)

这就是我有以下(用非标准的UML语法)

class A {
    class B b[*]
    class C
    class D
}

class B {
    class C c[*]
    string AttributeFoo = "bar"
}

class C {
    string AttributeThis = "is"
}

class D {
    string AttributeName = "d"
}

Desired output is something like this:

期望的输出是这样的:

<?xml version="1.0"?>
<a>
    <b attribute-foo="bar">
        <c attribute-this="is"/>
    </b>
    <c attribute-this="is"/>
    <d attribute-name="d"/>
</a>

What would you propose to be the best, and/or the simplest way of achieving this goal?

您认为什么是实现这一目标的最佳和/或最简单的方法?

6 个解决方案

#1

I would look at JAXB because a) you get it in the standard library and b) it isn't that complicated. This code requires Java 6:

我会看看JAXB,因为a)你在标准库中得到它并且b)它并不复杂。此代码需要Java 6:

@XmlRootElement public static class A {
  public List<B> b = new ArrayList<B>();
}

public static class B {
  public List<C> c = new ArrayList<C>();
  @XmlAttribute(name = "attribute-foo") public String attributeFoo = "foo";
}

public static class C {
  @XmlAttribute(name = "attribute-this") public String attributeThis = "is";
}

public static void main(String[] args) {
  A a = new A();
  a.b.add(new B());
  a.b.get(0).c.add(new C());
  JAXB.marshal(a, System.out);
}
//TODO: getters/setters, error handling and so on

Output:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<a>
    <b attribute-foo="foo">
        <c attribute-this="is"/>
    </b>
</a>

#2

The simplest way is to use XStream. See here for an idea what it does. It can be a bit buggy, but for simple tasks its great. For a more comprehensive (and reliable) technology, then JAXB (part of Java6, see javax.xml.bind) is the better option.

最简单的方法是使用XStream。请看这里了解它的作用。它可能有点儿麻烦,但对于简单的任务它很棒。对于更全面(和可靠)的技术,JAXB(Java6的一部分,请参阅javax.xml.bind)是更好的选择。

#3

I think it is the purpose of JAXB (http://jaxb.java.net/) to map Objects to/from XML

我认为JAXB(http://jaxb.java.net/)的目的是将对象映射到XML或从XML映射

#4

If you want to use tools, have a look at jaxb. Marshalling/Unmarshalling is what your're doing here, it's a common problem with a lot of solutions available.

如果您想使用工具,请查看jaxb。编组/解编是您在这里所做的事情,这是许多解决方案的常见问题。

I think it's the best (not reinventing the wheel) and it's the simplest (I've done it manually and it's really no fun - object graphs can be cyclic...)

我认为它是最好的(不是重新发明*)而且它是最简单的(我手动完成它并没有什么乐趣 - 对象图可以循环...)

#5

I like XMLBeans.

我喜欢XMLBeans。

#6

In my opinion if your not too bothered about performance I would stay away from Jaxb and take a look at some of the simpler frameworks. If performance is an issue I tend to favour jibx over jaxb for most situations.

在我看来,如果你对性能不太感兴趣,我会远离Jaxb并看看一些更简单的框架。如果性能是一个问题,我倾向于在大多数情况下支持jibx而不是jaxb。

In this situation I tend to use the simple project.

在这种情况下,我倾向于使用简单的项目。

http://simple.sourceforge.net/download/stream/doc/tutorial/tutorial.php#start

Just annotate your object model and away you go..... :-)

只是注释你的对象模型然后你走了..... :-)

@Root
public class Example {

   @Element
   private String text;

   @Attribute
   private int index;

   public Example() {
      super();
   }  

   public Example(String text, int index) {
      this.text = text;
      this.index = index;
   }

   public String getMessage() {
      return text;
   }

   public int getId() {
      return index;
   }
}

#1