Json与Bean互转，Timestamp类型的问题

Json与Java Bean互相转换时,Bean中的Timestamp字段是无法直接处理的，需要实现两个转换器。

DateJsonValueProcessor的作用是Bean转换为Json时将Timepstamp转换为指定的时间格式。

 1 import java.text.DateFormat;
 2 import java.text.SimpleDateFormat;
 3 import java.util.Date;
 4 import net.sf.json.JsonConfig;
 5 import net.sf.json.processors.JsonValueProcessor;
 6 /*** 将Bean中的Timestamp转换为json中的日期字符串*/
 7 public class DateJsonValueProcessor implements JsonValueProcessor {
 8     public static final String Default_DATE_PATTERN ="yyyy-MM-dd";
 9     private DateFormat dateFormat ;
10     public DateJsonValueProcessor(String datePattern){
11         try{
12             dateFormat  = new SimpleDateFormat(datePattern);}
13         catch(Exception e ){
14             dateFormat = new SimpleDateFormat(Default_DATE_PATTERN);
15         }
16     }
17     public Object processArrayValue(Object value, JsonConfig jsonConfig) {
18         return process(value);
19     }
20     public Object processObjectValue(String key, Object value,JsonConfig jsonConfig) {
21         return process(value);
22     }
23     private Object process(Object value){
24         return dateFormat.format((Date)value);
25     }
26 }

TimestampMorpher的作用则与DateJsonValueProcessor相反，它是在Jsonl转换为Bean时，会把指定的时间格式转换为Timestamp

 1 import java.sql.Timestamp;
 2 import java.text.ParseException;
 3 import java.text.SimpleDateFormat;
 4 import net.sf.ezmorph.MorphException;
 5 import net.sf.ezmorph.object.AbstractObjectMorpher;
 6 /*** 将json串中的日期字符串转换为bean中的Timestamp*/
 7 public class TimestampMorpher extends AbstractObjectMorpher {
 8 /*** 日期字符串格式*/
 9 private String[] formats;
10 public TimestampMorpher(String[] formats) {
11     this.formats = formats;
12 }
13 public Object morph(Object value) {
14 if( value == null){
15     return null;
16 }
17 if( Timestamp.class.isAssignableFrom(value.getClass()) ){
18     return (Timestamp) value;
19 }
20 if( !supports( value.getClass()) ){
21     throw new MorphException( value.getClass() + " 是不支持的类型");
22 }
23 String strValue=(String) value;
24 SimpleDateFormat dateParser=null;
25 for( int i = 0; i < formats.length ; i++ ){
26     if( null == dateParser ){
27         dateParser=new SimpleDateFormat(formats[i]);
28     }else{
29         dateParser.applyPattern(formats[i]);
30     }
31     try{
32         return new Timestamp( dateParser.parse( strValue.toLowerCase()).getTime() );}
33     catch (ParseException e) {
34         //e.printStackTrace();
35     }
36 }
37 return null;
38 }
39 @Override
40 public Class morphsTo() {
41     return Timestamp.class;
42 }
43 public boolean supports( Class clazz ){
44     return String.class.isAssignableFrom( clazz );
45 }
46 
47 }

测试一下。

 1 public class JsonTest {
 2 public static void main(String[] args) {
 3     String jsonStr="{"id":"101","name":"张三","age":"20","birthday":"1992-10-19 23:52:18"}";
 4     Student s=new Student();
 5     Timestamp b=Timestamp.valueOf("1992-10-19 23:52:18");
 6     s.setId(123456);
 7     s.setName("李四");
 8     s.setAge(20);
 9     s.setBirthday(b);
10     Student s1=jsonToBean(jsonStr);
11     System.out.println(s1.getBirthday());
12     System.out.println(beanToJson(s));
13 }
14 public static Student jsonToBean(String json){
15     String[] formats={"yyyy-MM-dd HH:mm:ss","yyyy-MM-dd"};
16     JSONUtils.getMorpherRegistry().registerMorpher(new TimestampMorpher(formats));
17     JSONObject jsonObject=JSONObject.fromObject(json);
18     return (Student)JSONObject.toBean(jsonObject,Student.class);
19 }
20 
21 public static String beanToJson(Student s){
22     JsonConfig config=new JsonConfig();
23     config.registerJsonValueProcessor(Timestamp.class, new DateJsonValueProcessor("yyyy-MM-dd HH:mm:ss"));
24     JSONObject json=JSONObject.fromObject(s,config);
25     return json.toString();}
26 }