Question

{
    "icon": "service",
    "title": "A",
    "type": "service",
    "children": [
        {
            "icon": "sharedlibraries",
            "title": "sharedlibraries",
            "type": "sharedlibraries",
            "children": [
                {
                    "icon": "war",
                    "title": "abc.war ( ui-shared-lib )",
                    "path": "abc/common/Services/1.2.0/lib/comp.war",
                    "reference": >"abc/common/templates/applications/11.1.2.3.jar/config/config.xml",
                    "type": "sharedlibrary",
                    "version": "11.1.2.0@11.1.2.0",
                    "children": [
                        {
                            "icon": "jar",
                            "title": "comp1.jar",
                            "path": >"abc/common/SharedServices/1.2.0/lib/comp.war/WEB-INF/lib/comp.jar",
                            "reference": >"abc/common/Services/1.2.0/lib/comp.war/WEB-INF/lib",
                            "type": "jar",
                            "thirdpartyjar": "true"

                        }
                    ]
                },
:
:
:
}

我需要检索，属性＆＃34;路径＆＃34;，所有节点的名称＆＃34; children＆＃34;，其中＆＃34; thirdpartyjar＆＃34; atribute = true。这有可能使用杰克逊吗？

更新：我试过以下：

          public void parse(File file) throws JsonProcessingException, 
          IOException {
                   ObjectMapper objectMapper = new ObjectMapper();
                   //JsonNode rootNode = objectMapper.readTree(file);
                   Model model = objectMapper.readValue(file, Model.class);
                   listThirdPartyJars(model);
                   while (true) {
                   Model children = model.getChildren();
                   if (!(children == null)) {
                         listThirdPartyJars(children);
                         model = children;
                   } else {
                         break;
                   }
                 }
                 }

            public void listThirdPartyJars(Model model) {
            boolean thirdPartyJars = model.isThirdPartyJar();
            if (thirdPartyJars == true)
                System.out.println(model.getPath());
      }

但是，遇到以下异常： com.fasterxml.jackson.databind.JsonMappingException：无法从START_ARRAY令牌中反序列化com.manager.Model的实例在[来源：D：\ my_json.json; line：4，column：22]（通过参考链：com.manager.Model [＆＃34; children＆＃34;]）

Answer 1

是，这是可能的。你需要有一个模型，它将自己作为属性引用，有点像：

public class Model {
    String icon;
    String title;
    String path;
    String reference;
    String type;          
    String version;
    boolean thirdPartyJar;
    Model children;
    ...getters, setters and overriden methods
}

您可以使用ObjectMapper将Json字符串映射到此对象，以进一步访问属性为thirdPartyJar的子项为真。

Answer 2

考虑您在问题中发布的JSON（通过一些修复使其有效）：

{
  "icon": "service",
  "title": "A",
  "type": "service",
  "children": [
    {
      "icon": "sharedlibraries",
      "title": "sharedlibraries",
      "type": "sharedlibraries",
      "children": [
        {
          "icon": "war",
          "title": "abc.war ( ui-shared-lib )",
          "path": "abc/common/Services/1.2.0/lib/comp.war",
          "reference": "abc/common/templates/applications/11.1.2.3.jar/config/config.xml",
          "type": "sharedlibrary",
          "version": "11.1.2.0@11.1.2.0",
          "children": [
            {
              "icon": "jar",
              "title": "comp1.jar",
              "path": "abc/common/SharedServices/1.2.0/lib/comp.war/WEB-INF/lib/comp.jar",
              "reference": "abc/common/Services/1.2.0/lib/comp.war/WEB-INF/lib",
              "type": "jar",
              "thirdpartyjar": "true"
            }
          ]
        }
      ]
    }
  ]
}

使用Jayway JsonPath和$..children[?(@.thirdpartyjar=='true')].path等查询可以解决问题，并会给您以下结果：

[
  "abc/common/SharedServices/1.2.0/lib/comp.war/WEB-INF/lib/comp.jar"
]

您可以对其进行测试here。

使用Jayway JsonPath

要使用Jayway JsonPath，请将以下依赖项添加到项目中：

<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>2.3.0</version>
</dependency>

然后阅读JSON文档：

String json = "...";
List<String> paths = JsonPath.read(json, "$..children[?(@.thirdpartyjar=='true')].path");

除Jayway JsonPath外，您可以将JSON映射到Java类（或简单地使用Jackson树模型），使用Jackson解析JSON，在树上递归迭代并提取所需的数据。

在使用Jackson的JsonParsing中，如何获得具有相同名称但位于不同层次结构中的所有节点？

2 个答案:

使用Jayway JsonPath