一。JSONBuilder可以向文件中写入写入json字符串。如下面的例子:
1 public class Test 2 { 3 public static void main(String args[]) throws IOException 4 { 5 File f = new File("d:" + File.separator + "test.txt"); 6 FileWriter fw = new FileWriter(f); 7 JSONBuilder builder = new JSONBuilder(fw); 8 builder.object(); 9 builder.key("Json"); 10 builder.value("Hello, World!"); 11 builder.endObject(); 12 fw.flush(); 13 fw.close(); 14 } 15 }
二。JSONBuilder:可以把一个对象转成json的输出
GsonBuilder json=new GsonBuilder();
User user=new User();
user.setName("jjr");
String userJson=json.create().toJson(user);
三。可以写个工具类好调用
FastJsonUtil:
public class FastJsonUtil { public static String bean2Json(Object obj) { return JSON.toJSONString(obj); } public static <T> T json2Bean(String jsonStr, Class<T> objClass) { return JSON.parseObject(jsonStr, objClass); } }
GsonUtil.java:
public class GsonUtil { private static Gson gson = new GsonBuilder().create(); public static String bean2Json(Object obj) { return gson.toJson(obj); } public static <T> T json2Bean(String jsonStr, Class<T> objClass) { return gson.fromJson(jsonStr, objClass); } public static String jsonFormatter(String uglyJsonStr) { Gson gson = new GsonBuilder().setPrettyPrinting().create(); JsonParser jp = new JsonParser(); JsonElement je = jp.parse(uglyJsonStr); return gson.toJson(je); } }
JacksonUtil.java
public class JacksonUtil { private static ObjectMapper mapper = new ObjectMapper(); public static String bean2Json(Object obj) { try { return mapper.writeValueAsString(obj); } catch (JsonProcessingException e) { e.printStackTrace(); return null; } } public static <T> T json2Bean(String jsonStr, Class<T> objClass) { try { return mapper.readValue(jsonStr, objClass); } catch (IOException e) { e.printStackTrace(); return null; } } }
JsonLibUtil.java
public class JsonLibUtil { public static String bean2Json(Object obj) { JSONObject jsonObject = JSONObject.fromObject(obj); return jsonObject.toString(); } @SuppressWarnings("unchecked") public static <T> T json2Bean(String jsonStr, Class<T> objClass) { return (T) JSONObject.toBean(JSONObject.fromObject(jsonStr), objClass); } }