使用Jackson JsonNodeFactory的最佳方式 [英] Best way to use Jackson JsonNodeFactory

问题描述

我正在使用Jackson构建自定义JSON对象。这是正确的方法吗？

I'm using Jackson to build a custom JSON object. Is the correct way of going about this?

它似乎运作良好（并且输出正确）但我可能会错过我使用JsonNodeFactory的方式。对象是否意味着像我在这里所做的那样传递？

It seems to work well (and the output is correct) but I may be missing the way I use JsonNodeFactory. Is the object meant to be passed around like I have done here?

JsonNodeFactory factory = JsonNodeFactory.instance;
ObjectNode dataTable = new ObjectNode(factory);
ArrayNode aaData = new ArrayNode(factory);

for (PkgLoad pkgLoad : pkgLoadList) {
    ObjectNode row = new ObjectNode(factory);
    row.put("ounces", pkgLoad.ounces);
    row.put("revolutions", pkgLoad.revolutions);
    aaData.add(row);
}

dataTable.put("aaData", aaData);

推荐答案

这是有效的，虽然意图是它的工厂创建实例。但最常见的是你只需使用ObjectMapper访问所有内容，例如：

This works, although intention is that it's factory that creates instances. But most commonly you just access all of it using ObjectMapper, like:

ObjectMapper mapper = new ObjectMapper();
ObjectNode dataTable = mapper.createObjectNode();
ArrayNode aa = dataTable.putArray("aaData");

单独的JsonNodeFactory的主要原因是允许您创建自定义节点类型（通常是子类标准实例）;然后配置ObjectMapper以使用不同的工厂。
为方便起见，ArrayNode和ObjectNode确实引用了一个工厂实例，它与putArray以及需要创建新节点的其他方法一起使用。

The main reason for separate JsonNodeFactory is to allow you to create custom node types (usually sub-classes of standard instances); and then configure ObjectMapper to use different factory. For convenience, ArrayNode and ObjectNode do have reference to a factory instance, which is used with "putArray" and other methods that need to create new nodes.

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