Alibaba Jackson's Objectmapper tool class package

A tool class that goes to the learning video:

Package com.example.demo.test;
Import Java.text.SimpleDateFormat;
Import java.util.ArrayList;
Import Java.util.Date;

Import java.util.List;


Import Org.apache.commons.lang3.StringUtils;
Import Com.fasterxml.jackson.annotation.JsonInclude.Include;
Import Com.fasterxml.jackson.databind.DeserializationFeature;
Import Com.fasterxml.jackson.databind.JavaType;
Import Com.fasterxml.jackson.databind.ObjectMapper;
Import Com.fasterxml.jackson.databind.SerializationFeature;

Import com.fasterxml.jackson.core.type.TypeReference;
	
	public class Jsonutils {private static Objectmapper Objectmapper = new Objectmapper ();
        static {//All field serialization//All fields of the object are all included in Objectmapper.setserializationinclusion (Include.always);
        Cancels the default conversion timestamps form objectmapper.configure (Serializationfeature.write_dates_as_timestamps,false);
		All date formats are unified into the following styles, i.e. Yyyy-mm-dd HH:mm:ss objectmapper.setdateformat ("Yyyy-mm-dd HH:mm:ss"); Error objectmapper.configure ignoring empty bean to JSON (SerialiZationfeature.fail_on_empty_beans,false); Ignoring the existence of a JSON string, but there is no corresponding attribute in the Java object.
	Prevent error Objectmapper.configure (DESERIALIZATIONFEATURE.FAIL_ON_UNKNOWN_PROPERTIES,FALSE);
            }/** * * @param obj * @return */public static <T> String obj2string (T obj) {if (obj = = null) {
        return null; } try {return obj instanceof String?
        (String) obj:objectMapper.writeValueAsString (obj);
            } catch (Exception e) {e.printstacktrace ();
        return null; }}/** * formatted * @param obj * @return */public static <T> String obj2stringpretty (T obj) {i
        F (obj = = null) {return null; } try {return obj instanceof String?
        (String) Obj:objectMapper.writerWithDefaultPrettyPrinter (). writevalueasstring (obj);
            } catch (Exception e) {e.printstacktrace ();
        return null; }}/** * String to Object * @param str * @pAram Clazz * @return * * public static <T> T string2obj (String str,class<t> clazz) {if (stringutils . IsEmpty (str) | |
        Clazz = = null) {return null; } try {return clazz.equals (string.class)?
        (T) Str:objectMapper.readValue (Str,clazz);
            } catch (Exception e) {e.printstacktrace ();
        return null; }}/** * field character to list such as collection * @param str * @param typereference * @return */public static <T> T Strin
            G2obj (String str, typereference typereference) {if (Stringutils.isempty (str) | | | typereference = NULL) {
        return null; } try {return (T) (Typereference.gettype (). Equals (String.class)? Str:objectMapper.readValue (Str,type
        Reference));
            } catch (Exception e) {e.printstacktrace ();
        return null;
}}/** * Almost ditto * @param str * @param collectionclass * @param elementclasses * @return * *	public static <T> T string2obj (String str,class<?> collectionclass,class<?> ... elementclasses) {
        Javatype Javatype = Objectmapper.gettypefactory (). Constructparametrictype (collectionclass,elementclasses);
        try {return objectmapper.readvalue (Str,javatype);
            } catch (Exception e) {e.printstacktrace ();
        return null;
		}} public static void Main (string[] args) {jsonutils js = new Jsonutils ();
		User U = New User (1L, "YWJ", 123, New Date ());
		User U2 = new user ();
		System.out.println (js.obj2string (U));
		System.out.println (Js.obj2stringpretty (U2));
		
		String str = js.obj2string (u);
		User U3 = js.string2obj (str, user.class);
		System.out.println (U3.getname ()); Added attribute minus attribute User U5 = js.string2obj ("{\" id\ ": 1,\" name\ ": \" ywj\ ", \" age2222\ ": 123,\" date\ ": \" 2018-01-14 22:14:18\ ", \"
		Abc\ ": \" Abc\ "}", User.class);
		
		System.out.println (U5.getname ()); list<user> list = new Arraylist<user> ();
		List.add (New User (1L, "YWJ", 123, New Date ()));
		List.add (New User (2L, "Ywj2", 123, New Date ()));
		str = js.obj2string (list);
		
		System.out.println (str);
		List = Js.string2obj (str, new typereference<list<user>> () {});
		
		System.out.println (list.size () + ":" +list.get (1). GetName ());
		List = Js.string2obj (str, list.class, user.class);
	System.out.println (list.size () + ":" +list.get (1). GetName ());
 }
}

Ok