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 }