使用Java中的GSON解析复杂的Json对象

我有一个非常长的JSON来解析Gson，但为了简洁起见，我将它修剪为这个例子：

{ "volumes": [ { "status": "available", "managed": true, "name": "va_85621143-1133-412f-83b4-57a01a552638_", "support": { "status": "supported" }, "storage_pool": "pfm9253_pfm9254_new", "id": "afb8e294-6188-4907-9f6f-963c7623cecb", "size": 9 }, { "status": "in-use", "managed": false, "name": "bt_newd20", "support": { "status": "not_supported", "reasons": [ "This volume is not a candidate for management because it is already attached to a virtual machine. To manage this volume with PowerVC, select the virtual machine to which the volume is attached for management. The attached volume will be automatically included for management." ] }, "storage_pool": "KVM", "mapped_wwpns": [ "2101001B32BD4280", "2100001B329D4280", "2101001B32BD637E", "2100001B329D637E" ], "id": "c7838c79-17ca-3cbc-98e5-3567fde902d8", "size": 0 }, { "status": "available", "managed": true, "name": "vdisk138", "support": { "status": "supported" }, "storage_pool": "Chassis2_IBMi", "id": "b6d00783-9f8c-40b8-ad78-956b0299478c", "size": 100 } ] } 

从SO和其他几个地方，我发现我需要定义一个顶层容器，如下面的一个，但我不知道如何完成它的定义

 static class VolumeContainer { //I don't know what do in here. This is the first problem } 

然后是每个Volume一个类

 static class Volume { private String status; private boolean managed; private String name; //This is the second problem.The "support" variable should not be a string. //It is in {}. Just for information, I won't use it. //private String support; private String storagePool; private List mapped_wwpns; private String id; private String size; } 

我试图解析它，这是我编码到目前为止：

 JsonParser parser = new JsonParser(); JsonObject obj = parser.parse(response).getAsJsonObject(); Gson gson = new Gson(); 

JSON字符串存储在名为response的变量中

 VolumeContainer vc = gson.fromJson(response,VolumeContainer.class); 

我的最终要求是id和相关name的HashTable 。

Answer 1

第一个问题 ：您的VolumeContainer需要：

 public class VolumeContainer { public List volumes; } 

它不需要是静态的。

第二个问题 ：你的Volume类应该是这样的：

 public class Volume { private String status; private Boolean managed; private String name; private Support support; private String storage_pool; private String id; private int size; private List mapped_wwpns; public String getId(){return id;} public String getName(){return name;} } 

我定义了一个名为Support的类，如下所示：

 public class Support { private String status; private List reasons; } 

第三个问题 ：解析，如果response字符串包含您的示例数据，只需解析如下：

 Gson g = new Gson(); VolumeContainer vc = g.fromJson(response, VolumeContainer.class); 

第四个问题 ：拿到地图。 最后得到你的HashMap ，就这样做：

 HashMap hm = new HashMap(); for(Volume v: vc.volumes){ hm.put(v.getId(), v.getName()); }