Java Jackson配置自己的json
我开始玩Jackson json,但我在某个点上卡住了。我得到了返回的Json:Java Jackson配置自己的json,java,json,jackson,Java,Json,Jackson,我开始玩Jackson json,但我在某个点上卡住了。我得到了返回的Json: [ { "id": "1", "groups": [ { "id": "1", "name": "Group99", "students": [ { "studentId
[
{
"id": "1",
"groups": [
{
"id": "1",
"name": "Group99",
"students": [
{
"studentId": "1"
},
{
"studentId": "2"
},
{
"studentId": "3"
}
],
"schoolId": 10
},
{
"id": "2",
"name": "Group100",
"students": [
{
"studentId": "1"
},
{
"studentId": "2"
},
{
"studentId": "3"
}
],
"schoolId": 10
}
]
}
]
我希望得到一个JSON,其中没有student数组。像这样
[
{
"id": "1",
"groups": [
{
"id": "1",
"name": "Group99",
"schoolId": 10
},
{
"id": "2",
"name": "Group100",
"schoolId": 10
}
]
}
]
现在,我从数据库中获取了一个列表,并创建了一个ObjectMapper,它只返回ObjectMapper.writeValueAsString(列表)。如何修改列表,以便在JSON with Jackson中排除学生数组
编辑JAVA代码
我现在拥有的Java代码是
List<Assessment> assessments = (List<Assessment>) assessmentRepository.findGroupsByUsernameAndAssessmentId(username, assessmentId);
//2. Convert JSON to Java object
ObjectMapper mapper = new ObjectMapper();
// create the new JSON
List<String> groups = new ArrayList<>();
for(int i = 0; i <= assessments.size() - 1; i++){
for(int k = 0; k < assessments.get(i).getGroups().length; k++){
// create the String with only the wanted information
}
}
return mapper.writeValueAsString(groups);
List assessments=(List)assessmentRepository.findGroupsByUserName和assessmentId(用户名,assessmentId);
//2. 将JSON转换为Java对象
ObjectMapper mapper=新的ObjectMapper();
//创建新的JSON
列表组=新的ArrayList();
对于(inti=0;i您可以使用Jackson属性为您不想在POJO类中显示的列表设置@JsonIgnore
编辑:/
如果这对您来说很严格,您也可以为对象映射器编写一个函数。在您的情况下,函数应该与工厂一样工作。注意:您确实应该包括Java类定义,而不仅仅是JSON——数据绑定是从一个转换到另一个再转换回来的艺术;因此仅JSON不足以回答大多数问题。谢谢您的提示,但我想在另一个json中返回属性,因此@JsonIgnore注释不是最合适的。谢谢,这正是我所需要的:)它工作得很好
Assessment assessment = (Assessment) assessmentRepository.findGroupsByUsernameAndAssessmentId(username, assessmentId);
// 2. Convert JSON to Java object
ObjectMapper mapper = new ObjectMapper();
// create the new JSON
ArrayList<Object> jsonWithoutTeacherAndStudents = new ArrayList<Object>();
HashMap<String, String> jsonKeyAndValueMap = new HashMap<>();
GroupSummary[] summary = assessment.getGroups();
for (int i = 0; i < assessment.getGroups().length; i++) {
jsonKeyAndValueMap.put("id", summary[i].getId());
jsonKeyAndValueMap.put("name", summary[i].getName());
jsonKeyAndValueMap.put("schoolId", Integer.toString(summary[i].getSchoolId()));
jsonWithoutTeacherAndStudents.add(mapper.writeValueAsString(jsonKeyAndValueMap));
}
return jsonWithoutTeacherAndStudents.toString();