I'm getting a JSON array in string like
[ { "id":"ca.Primary_Diagnosis_Dt",
"field":"ca.Primary_Diagnosis_Dt",
"type":"date",
"input":"text",
"operator":"not_equal",
"value":"2016/06/07"
},
{ "id":"ca.Clinical_Stage",
"field":"ca.Clinical_Stage",
"type":"integer",
"input":"select",
"operator":"equal",
"value":"I"
}
]
i just want to save the value of id ,operator and value in LIST please help
Online : Working code
First create a class to store your values :
class Data{
String id;
String operator;
String value;
}
Then iterate over the json :
JSONArray jsonArr = new JSONArray("[JSON Stirng]");
List<Data> dataList = new ArrayList<>();
for (int i = 0; i < jsonArr.length(); i++) {
JSONObject jsonObj = jsonArr.getJSONObject(i);
Data data = new Data();
data.id = jsonObj.getString("id");
data.operator = jsonObj.getString("operator");
data.value = jsonObj.getString("value");
dataList.add(data);
}
Now dataList has your data!
P.S. : Use getter/setters in Data class
JAR : http://www.java2s.com/Code/Jar/j/Downloadjavajsonjar.htm
You can do that with a JSon library such as org.glassfish.javax.json
In Maven use
<dependency>
<groupId>org.glassfish</groupId>
<artifactId>javax.json</artifactId>
<version>1.0.4</version>
</dependency>
Then read the string to a JsonArray:
JsonArray ja = Json.createReader(new StringReader(input)).readArray();
Then iterate over the list, map the objects to a new objects with just the values you need:
List<JsonObject> list = ja.stream()
.map(o -> (JsonObject) o)
.map(jo -> Json.createObjectBuilder()
.add("id", jo.getJsonString("id"))
.add("operator", jo.getJsonString("operator"))
.add("value", jo.getJsonString("value")).build())
.collect(Collectors.toList());
In case you could not use JsonObject as output, you may use a value object instead - just like Himanshu Tyagi proposed - and map the values to that object.
In your case, I think, the JSON should be parsed into a List<Map<String,String>>. This can be done using Jackson. Following is a method that converts a JSON string into List<Map<String,String>>:
public static List<Map<String, String>> toList(String json) throws IOException {
List<Map<String, String>> listObj;
ObjectMapper MAPPER = new ObjectMapper();
listObj = MAPPER.readValue(json, new TypeReference<ArrayList<HashMap<String, String>>>() {
});
return listObj;
}
If you have created a POJO class for it then you can use:
public static List<PojoClass> toList(String json) throws IOException {
List<PojoClass> listObj;
ObjectMapper MAPPER = new ObjectMapper();
listObj = MAPPER.readValue(json, new TypeReference<ArrayList<PojoClass>>() {
});
return listObj;
}
Maven dependency for Jackson:
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.6.3</version>
</dependency>
