net.mograsim.logic.model/src/net/mograsim/logic/model/util/JsonHandler.java

   1 package net.mograsim.logic.model.util;
   2
   3 import java.io.BufferedReader;
   4 import java.io.FileInputStream;
   5 import java.io.FileWriter;
   6 import java.io.IOException;
   7 import java.io.InputStream;
   8 import java.io.InputStreamReader;
   9 import java.util.stream.Collectors;
  10
  11 import com.google.gson.Gson;
  12 import com.google.gson.GsonBuilder;
  13 import com.google.gson.JsonElement;
  14
  15 public class JsonHandler
  16 {
  17         public final static Gson parser = new GsonBuilder().setPrettyPrinting().create();
  18
  19         public static <T> T readJson(String path, Class<T> type) throws IOException
  20         {
  21                 try (FileInputStream jsonStream = new FileInputStream(path))
  22                 {
  23                         return readJson(jsonStream, type);
  24                 }
  25         }
  26
  27         /**
  28          * @param input The Stream is closed after being read
  29          */
  30         public static <T> T readJson(InputStream input, Class<T> type) throws IOException
  31         {
  32                 try (InputStreamReader reader = new InputStreamReader(input); BufferedReader bf = new BufferedReader(reader))
  33                 {
  34                         return fromJson(bf.lines().collect(Collectors.joining("\n")), type);
  35                 }
  36         }
  37
  38         public static <T> T fromJson(String src, Class<T> type)
  39         {
  40                 // throw away legacy version line
  41                 String rawJson = src.lines().dropWhile(s -> s.length() == 0 || s.charAt(0) != '{').collect(Collectors.joining());
  42                 return parser.fromJson(rawJson, type);
  43         }
  44
  45         public static <T> T fromJsonTree(JsonElement src, Class<T> type)
  46         {
  47                 return parser.fromJson(src, type);
  48         }
  49
  50         public static void writeJson(Object o, String path) throws IOException
  51         {
  52                 try (FileWriter writer = new FileWriter(path))
  53                 {
  54                         writer.write(toJson(o));
  55                 }
  56         }
  57
  58         public static String toJson(Object o)
  59         {
  60                 return parser.toJson(o);
  61         }
  62
  63         public static JsonElement toJsonTree(Object o)
  64         {
  65                 return parser.toJsonTree(o);
  66         }
  67 }