Jackson Map デシリアライズ

JSON → Map

import com.fasterxml.jackson.core.type.TypeReference;

TypeReference を使って

Map<String, Object> map = new ObjectMapper()
   .readValue(jsontxt, new TypeReference<LinkedHashMap<String, Object>>(){});

try(InputStream inst = new FileInputStream(Thread.currentThread().getContextClassLoader()
.getResource("./application.json").getPath())){
     Map<String, Object> map = new ObjectMapper().readValue(inst, new TypeReference<LinkedHashMap<String, Object>>(){});
}catch(IOException e) {
      e.printStackTrace();
}