java - 如何访问嵌套Json中的元素（Map) 数据并使用 java.util.stream 修改数据

Question

我想使用 java.util.stream 修改嵌套 json (Map<String, Object>) 中的数据。

这是 Json 数据

{
      "schoolId": "10928391",
      "schoolName": "school A",
      "teachers" : [
        {
          "teacherId": "00001",
          "teacherName:": "teacher A",
          "subject": "Computer Science",
          "lectures": [
            {
              "id": "CS102",
              "name": "Algorithm"
            },
            {
              "id": "CS330",
              "name": "Data Communications and Networking"
            }
          ]
        },
        {
          "teacherId": "00002",
          "teacherName:": "teacher B",
          "subject": "Computer Science",
          "lectures": [
            {
              "id": "CS103",
              "name": "Data Structure"
            },
            {
              "id": "CS104",
              "name": "Data Structures in C++"
            }
          ]
        },
        {
          "teacherId": "00003",
          "teacherName:": "teacher C",
          "subject": "Computer Science",
          "lectures": [
            {
              "id": "CS100",
              "name": "Introduction to Programming (Java)"
            },
            {
              "id": "CS401",
              "name": "Object Oriented Programming"
            }
          ]
        }
      ]
    }

--

ObjectMapper mapper = new ObjectMapper(); 
Map<String, Object> schoolInfo = mapper.converValue(restTemplate.exchange(url, HttpMethod.GET,  .... ).getBody(), HashMap.class); 

上面的 Json 数据在 schoolInfo 里面

我要访问和修改的数据是讲座。我试图修改讲座（数组）中的所有元素。

例如，

"lectures": [
        {
          "id": "CS102",
          "name": "Algorithm"
        },
        {
          "id": "CS330",
          "name": "Data Communications and Networking"
        }
      ]
    

替换讲座数据中的所有讲座信息，如下所示。

"lectures": [
        {
          "lectureId": "CS102",
          "lectureName": "Algorithm",
          "lectureRoom": "Room A-1"
        },
        {
          "lectureId": "CS330",
          "lectureName": "Data Communications and Networking",
          "lectureRoom": "Room A-2"
        }
      ]

使用地图，过滤器我可以访问“教师”对象，但我不知道如何在“教师”中获取“讲座”对象

System.out.println(jsonMap.entrySet().stream()
            .filter(map -> map.getKey().equals("teachers")).collect(Collectors.toList()).toString());

任何建议都会非常有帮助！

标签： javadictionarylambdastream