Gremlin：以类似 JSON 的方式漂亮地打印查询结果答案

【问题标题】：Gremlin: Pretty print a query results in a JSON-like wayGremlin：以类似 JSON 的方式漂亮地打印查询结果
【发布时间】：2015-12-07 01:11:14
【问题描述】：

我想以 JSON 样式打印 Gremlin 查询结果。也就是说，一个键中的所有属性：值格式，每行一个，以及可选的边缘，例如“边缘标签”-> v[1234] 等。

在 Java 中，当我在顶点上使用 toString() 时，它只会在一行上打印我想要的内容。

我试过g.V().toString()，但打印出来的结果就像toString() 不存在一样。

也许一些 Groovy 技巧可以与 getProperties() 结合使用？

（有一个类似的问题，How to print out Gremlin pipe / traversal results，但这是不同的。）

【问题讨论】：

标签： pretty-print gremlin

【解决方案1】：

如果您使用 Gremlin 2.x，您可以使用 GraphSONUtility http://www.tinkerpop.com/docs/javadocs/blueprints/2.6.0/com/tinkerpop/blueprints/util/io/graphson/GraphSONUtility.html

         \,,,/
         (o o)
-----oOOo-(_)-oOOo-----
gremlin> g = new TinkerGraph()
==>tinkergraph[vertices:0 edges:0]
gremlin> v = g.addVertex()
==>v[0]
gremlin> v.setProperty('name','jason')
==>null
gremlin> v.setProperty('type','person')
==>null
gremlin> w = g.addVertex()
==>v[1]
gremlin> w.setProperty('name','ondra')
==>null
gremlin> w.setProperty('type','person')
==>null
gremlin> e = v.addEdge('chat', w)
==>e[2][0-chat->1]
gremlin> e.setProperty('datestamp','20150910')
==>null
gremlin> GraphSONUtility.jsonFromElement(v, null, GraphSONMode.NORMAL)
==>{"name":"jason","type":"person","_id":"0","_type":"vertex"}
gremlin> GraphSONUtility.jsonFromElement(w, ['name'] as Set, GraphSONMode.NORMAL)
==>{"name":"ondra","_id":"1","_type":"vertex"}
gremlin> GraphSONUtility.jsonFromElement(e, null, GraphSONMode.NORMAL)
==>{"datestamp":"20150910","_id":"2","_type":"edge","_outV":"0","_inV":"1","_label":"chat"}

如果你想变换整个图，可以使用GraphSONWriter http://www.tinkerpop.com/docs/javadocs/blueprints/2.6.0/com/tinkerpop/blueprints/util/io/graphson/GraphSONWriter.html

gremlin> os = new FileOutputStream('/tmp/graph.json')
==>java.io.FileOutputStream@7889a1ac
gremlin> GraphSONWriter.outputGraph(g, os)
==>null
gremlin> new File('/tmp/graph.json').text
==>{"mode":"NORMAL","vertices":[{"name":"jason","type":"person","_id":"0","_type":"vertex"},{"name":"ondra","type":"person","_id":"1","_type":"vertex"}],"edges":[{"datestamp":"20150910","_id":"2","_type":"edge","_outV":"0","_inV":"1","_label":"chat"}]}

【讨论】：