XStream：使用 XStreamImplicit 省略集合答案

【问题标题】：XStream: Omit collection with XStreamImplicitXStream：使用 XStreamImplicit 省略集合
【发布时间】：2012-07-05 14:37:56
【问题描述】：

我正在尝试使用 XStream 将一个小对象图输出到 JSON。只需要输出，不需要反序列化。

对象很简单：

@XStreamAlias("players")
public class Players {

    @XStreamImplicit
    private List<Player> players = new ArrayList<Player>();

    public Players() {
        for (int i = 0; i < 5; ++i) {
            players.add(new Player("Player " + i));
        }
    }
}

@XStreamAlias("player")
public class Player {
    private String name;
    public Player(String name) {
        this.name = name;
    }
}

幸运的是，JSON 中省略了不必要的列表包装元素：

{ players: { player: { name: "Player 4"}}}

但不幸的是，只打印了最后一个元素。

我正在使用 XStream 1.4.2，像这样初始化：

XStream xstream = new XStream(new JsonHierarchicalStreamDriver());
xstream.setMode(XStream.NO_REFERENCES);
xstream.aliasSystemAttribute(null, "class");
xstream.autodetectAnnotations(true);
String out = xstream.toXML(xstramAliasObject);

据我所知，设置类似于这个问题：XStream Alias of List root elements。

我的例子有什么问题？

提前致谢！问候，迈克尔

【问题讨论】：

标签： java json list xstream

【解决方案1】：

我使用的是同一个库，但得到了整个消息..

{"players": {
  "player": {
    "name": "Player 0"
  },
  "player": {
    "name": "Player 1"
  },
  "player": {
    "name": "Player 2"
  },
  "player": {
    "name": "Player 3"
  },
  "player": {
    "name": "Player 4"
  }
}}

这是代码..

public static void main(String[] args) {
        Players xstramAliasObject = new Players();
        XStream xstream = new XStream(new JsonHierarchicalStreamDriver());
        xstream.setMode(XStream.NO_REFERENCES);
        xstream.aliasSystemAttribute(null, "class");
        xstream.autodetectAnnotations(true);
        System.out.println("--- "+xstream.toXML(xstramAliasObject));
    }

【讨论】：