很实用的数据类型转换以及读取文件中的数据

/*
	 * 001.json转换成对象
	 * 
	 * @param:传入对象，json字符串
	 * 
	 * @return:Object
	 */
	public static Object jsonToObj(Object obj, String jsonStr)
			throws JsonParseException, JsonMappingException, IOException {
//		System.out.println(

public class Reader {
    public static String readToString(String fileName) {
        String encoding = "UTF-8";
        File file = new File(fileName);
        Long filelength = file.length();
        byte[] filecontent = new byte[filelength.intValue()];
        try {
            FileInputStream in = new FileInputStream(file);
            in.read(filecontent);
            in.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            return new String(filecontent, encoding);
        } catch (UnsupportedEncodingException e) {
            System.err.println("The OS does not support " + encoding);
            e.printStackTrace();
            return null;
        }
    }
}

　　

obj.toString()); // System.out.println(jsonStr); ObjectMapper mapper = new ObjectMapper(); //mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); return obj = mapper.readValue(jsonStr, obj.getClass()); } /* * 002.对象转换成json * * @param:传入对象 * * @return:json字符串 */ public static String objToJson(Object obj) throws JsonProcessingException { ObjectMapper mapper = new ObjectMapper(); return mapper.writeValueAsString(obj); } public static Map<String, Object> jsonToMap(String jsonString) throws JsonParseException, JsonMappingException, IOException { ObjectMapper MAPPER = new ObjectMapper(); // JavaType jvt = MAPPER.getTypeFactory().constructParametricType(HashMap.class,String.class,String.class); HashMap<String,Object> mmap = MAPPER.readValue(jsonString, HashMap.class); // Map<String,String> urMap = MAPPER.readValue(jsonString, jvt); return mmap; }