对JSONObject.fromObject 的处理
1.扩展JsonValueProcessor接口（注意对null的处理）
import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonValueProcessor;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
/***
* 将Bean中的Timestamp转换为json中的日期字符串
* @author dxswzj@163.com
* */
public class DateJsonValueProcessor implements JsonValueProcessor {
public static final String Default_DATE_PATTERN ="yyyy-MM-dd";
private DateFormat dateFormat ;
public DateJsonValueProcessor(String datePattern){
try{
dateFormat = new SimpleDateFormat(datePattern);}
catch(Exception e ){
dateFormat = new SimpleDateFormat(Default_DATE_PATTERN);
}
}
public Object processArrayValue(Object value,JsonConfig jsonConfig) {
if(null!=value){
return process(value);
}else{
return "";
}
}
public Object processObjectValue(String key,Object value,JsonConfig jsonConfig) {
if(null!=value){
return process(value);
}else{
return "";
}
}
private Object process(Object value){
return dateFormat.format((Date)value);
}
}
2.转化时 JSONObject.fromObject 加上参数
Question question = questionService.selectQuestionById(id);
JsonConfig config=new JsonConfig();
config.registerJsonValueProcessor(Timestamp.class,new DateJsonValueProcessor("yyyy-MM-dd HH:mm:ss"));
config.registerJsonValueProcessor(java.util.Date.class,new DateJsonValueProcessor("yyyy-MM-dd"));
JSONObject json = JSONObject.fromObject(question,config);
这样json里得到的日期格式就是按我们定义的格式显示
对toBean()的处理
json日期格式可以是 2018-02-01 12:23:12 或 2014-08-08
1.编写一个Morpher类继承自AbstractObjectMorpher
class TimeStampMorpher extends AbstractObjectMorpher{
private Logger LOG = Logger.getLogger(TimeStampMorpher.class);
private String[] formats = new String[]{"yyyy-MM-dd hh:mm:ss","yyyy-MM-dd"};
public void setFormats(String[] formats) {
this.formats = formats;
}
public TimeStampMorpher() {
// TODO Auto-generated constructor stub
}
public TimeStampMorpher(String[] formats) {
this.formats = formats;
}
@Override
public Object morph(Object dateStr) {
// TODO Auto-generated method stub
if(null == dateStr){
return null;
}
if(Timestamp.class.isAssignableFrom(dateStr.getClass())){
return (Timestamp)dateStr;
}
if(!supports(dateStr.getClass())){
throw new MorphException(dateStr.getClass()+"不是支持的类型！");
}
String strValue = (String)dateStr;
SimpleDateFormat dateParser = null;
for(int i=0,k=formats.length;i<k;i++){
if(null == dateParser){
dateParser = new SimpleDateFormat(formats[i]);
}else{
dateParser.applyPattern(formats[i]);
}
try{
return new Timestamp(dateParser.parse(strValue.toLowerCase()).getTime()));
}catch(ParseException e){
e.printStackTrace();
}
}
return new java.sql.Timestamp(System.currentTimeMillis());//返回默认日期
}
@Override
public Class morphsTo() {
// TODO Auto-generated method stub
return Timestamp.class;
}
public boolean supports(Calss claszz){
return String.class.isAssignableFrom(claszz);
}
} 在toBean的地方
JSONUtils.getMorpherRegistry().registerMorpher(new TimestampMorpher()); Question question = (Question)JSONObject.toBean(questionJson,Question.class);
随便提下 如果Question有分录的话需要这样转
Map<Stirng,Class> classMap = new HashMap<Stirng,Class>();
classmap.put("questionEntry",QuestionEntry.class);
question = (Question)JSONObject.toBean(questionJson,Question.class,calssMap);
其中Question 有属性
private List<QuestionEntry> questionEntry;
原文链接：https://www.f2er.com/json/290100.html