英文:
Converting Map to JSON in Java
问题
我有一个地图
Map<String, Application.RiskFactor> appRiskFactorsMap = app.getRiskFactors();
它里面有这种数据
{risk1=Application.RiskFactor(risk=risk1, question=question1,
factor=true), risk2=Application.RiskFactor(risk=risk2,
question=question2?, factor=true),
risk3=Application.RiskFactor(risk=risk3, question=question3?,
factor=true)}
我将其转换为JSON，并获得此输出。
{"risk1":{"risk":"risk1","question":"question1?","factor":"true"},"":
{"risk":"risk2","question":"question2?","factor":"true"},"risk3":
{"risk":"risk3","question":"question3?","factor":"true"}}
我有这个JSON转换器类
package system.referee.util;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
public final class JsonUtils {
private static final ObjectMapper MAPPER = new ObjectMapper();
static {
// 反序列化时忽略未知字段
MAPPER.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
// 序列化时忽略 null 和 Optional.EMPTY 字段
MAPPER.setSerializationInclusion(JsonInclude.Include.NON_ABSENT);
}
public static <T> String toJson(T obj) {
try {
return MAPPER.writeValueAsString(obj);
} catch (JsonProcessingException e) {
return "";
}
}
public static <T> T fromJson(String json, Class<T> type) {
try {
return MAPPER.readValue(json, type);
} catch (JsonProcessingException e) {
return null;
}
}
}
我想以这种格式打印JSON
{"risk":"risk1","question":"question1?","factor":"true"},
{"risk":"risk2","question":"question2?","factor":"true"},
{"risk":"risk3","question":"question3?","factor":"true"}
有没有办法实现这样的格式？我无法找到任何关于这个的帮助。非常感谢
英文:
I am having a map
Map<String, Application.RiskFactor> appRiskFactorsMap = app.getRiskFactors();
It has this data kind of in it
{risk1=Application.RiskFactor(risk=risk1, question=question1,
factor=true), risk2=Application.RiskFactor(risk=risk2,
question=question2?, factor=true),
risk3=Application.RiskFactor(risk=risk3, question=question3?,
factor=true)}
I am converting it into JSON and having this output.
{"risk1":{"risk":"risk1","question":"question1?","factor":"true"},"":
{"risk":"risk2","question":"question2?","factor":"true"},"risk3":
{"risk":"risk3","question":"question3?","factor":"true"}}
I have this JSON converter class
package system.referee.util;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
public final class JsonUtils {
private static final ObjectMapper MAPPER = new ObjectMapper();
static {
// Ignore unknown fields while deserialization
MAPPER.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
// Ignore null & Optional.EMPTY fields while serialization
MAPPER.setSerializationInclusion(JsonInclude.Include.NON_ABSENT);
}
public static <T> String toJson(T obj) {
try {
return MAPPER.writeValueAsString(obj);
} catch (JsonProcessingException e) {
return "";
}
}
public static <T> T fromJson(String json, Class<T> type) {
try {
return MAPPER.readValue(json, type);
} catch (JsonProcessingException e) {
return null;
}
}
}
I want to print the JSON in this format
{"risk":"risk1","question":"question1?","factor":"true"},
{"risk":"risk2","question":"question2?","factor":"true"},
{"risk":"risk3","question":"question3?","factor":"true"}
is there any way to achieve that? I am unable to find any help with this. thanks a lot
答案1
得分: 1
你应该忽略键，只对值进行序列化：
JsonUtils.toJson(appRiskFactorsMap.values())
结果将是一个 JSON 数组。
英文:
You should ignore keys and serialise only values:
JsonUtils.toJson(appRiskFactorsMap.values())
Result will be a JSON Array.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论