关键字: struts2
struts2提供了一个时间标签:
- <s:date name="todayDate" format="yyyy-MM-dd" />
<s:date name="todayDate" format="yyyy-MM-dd" />
但这个标签很只能在显示的时候用,但如果我想在输入框里显示时间,让用户直接修改时间,怎么弄?datepicker?选择太麻烦,我想让用户输入,并且兼容多种日期格式。还有,如果用时间标签的话,每个地方都需要指定format,如果我想修改一下格式,所有的时间显示都变,怎么弄?
翻了一下struts2的源码,和文档,找到一个办法。 com.opensymphony.xwork2.util.XWorkConverter
- * <p/> In some situations you may wish to apply a type converter globally.
- * This can be done by editing the file
- * <b>xwork-conversion.properties</b> in the root of your class path
- * (typically WEB-INF/classes) and providing a
- * property in the form of the class name of the object you wish to convert
- * on the left hand side and the class name of
- * the type converter on the right hand side. For example, providing
- * a type converter for all Point objects would mean
- * adding the following entry:
- *
- * <p/><b>com.acme.Point = com.acme.PointConverter</b>
* <p/> In some situations you may wish to apply a type converter globally. * This can be done by editing the file * <b>xwork-conversion.properties</b> in the root of your class path * (typically WEB-INF/classes) and providing a * property in the form of the class name of the object you wish to convert * on the left hand side and the class name of * the type converter on the right hand side. For example, providing * a type converter for all Point objects would mean * adding the following entry: * * <p/><b>com.acme.Point = com.acme.PointConverter</b>
XWorkConverter,先在classpath root下找xwork-conversion.properties文件,这个文件定义了全局转换。然后每遇到新的类需要转换,便查找是否有特殊的自定义转换配置。特殊自定义转换配置文件的路径是:
- className.replace('.', '/') + "-conversion.properties";
className.replace('.', '/') + "-conversion.properties";
比方com.acme.Point的转换配置就是classpath 下的/com/acme/Point-coversion.properties文件。
ok,这个问题好解决了。
我的xwork-coversion.properties文件:
- java.util.Date=cn.jolstar.struts.type.DateTypeConverter
java.util.Date=cn.jolstar.struts.type.DateTypeConverter
我的DateTypeConverter代码:
- /**
- *
- */
- package cn.jolestar.struts.type;
- import java.text.DateFormat;
- import java.text.ParseException;
- import java.text.SimpleDateFormat;
- import java.util.Date;
- import java.util.Map;
- import org.apache.log4j.Logger;
- import org.apache.struts2.util.StrutsTypeConverter;
- /**
- * @author jolestar
- *
- */
- public class DateTypeConverter extends StrutsTypeConverter {
- private static final Logger log = Logger.getLogger(DateTypeConverter.class);
- public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";
- //暂时只考虑这几种日期格式
- public static final DateFormat[] ACCEPT_DATE_FORMATS = {
- new SimpleDateFormat(DEFAULT_DATE_FROMAT),
- new SimpleDateFormat("yyyy年MM月dd日"),
- new SimpleDateFormat("yyyy/MM/dd") };
- /**
- *
- */
- public DateTypeConverter() {
- }
- /*
- * (non-Javadoc)
- *
- * @see org.apache.struts2.util.StrutsTypeConverter#convertFromString(java.util.Map,
- * java.lang.String[], java.lang.Class)
- */
- @Override
- public Object convertFromString(Map context, String[] values, Class toClass) {
- if (values[0] == null || values[0].trim().equals(""))
- return null;
- for (DateFormat format : ACCEPT_DATE_FORMATS) {
- try {
- return format.parse(values[0]);
- } catch (ParseException e) {
- continue;
- } catch (RuntimeException e) {
- continue;
- }
- }
- log.debug("can not format date string:" + values[0]);
- return null;
- }
- /*
- * (non-Javadoc)
- *
- * @see org.apache.struts2.util.StrutsTypeConverter#convertToString(java.util.Map,
- * java.lang.Object)
- */
- @Override
- public String convertToString(Map context, Object o) {
- if (o instanceof Date) {
- SimpleDateFormat format = new SimpleDateFormat(
- DEFAULT_DATE_FORMAT);
- try {
- return format.format((Date) o);
- } catch (RuntimeException e) {
- return "";
- }
- }
- return "";
- }
- }
/** * */ package cn.jolestar.struts.type; import java.text.DateFormat; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Map; import org.apache.log4j.Logger; import org.apache.struts2.util.StrutsTypeConverter; /** * @author jolestar * */ public class DateTypeConverter extends StrutsTypeConverter { private static final Logger log = Logger.getLogger(DateTypeConverter.class); public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd"; //暂时只考虑这几种日期格式 public static final DateFormat[] ACCEPT_DATE_FORMATS = { new SimpleDateFormat(DEFAULT_DATE_FROMAT), new SimpleDateFormat("yyyy年MM月dd日"), new SimpleDateFormat("yyyy/MM/dd") }; /** * */ public DateTypeConverter() { } /* * (non-Javadoc) * * @see org.apache.struts2.util.StrutsTypeConverter#convertFromString(java.util.Map, * java.lang.String[], java.lang.Class) */ @Override public Object convertFromString(Map context, String[] values, Class toClass) { if (values[0] == null || values[0].trim().equals("")) return null; for (DateFormat format : ACCEPT_DATE_FORMATS) { try { return format.parse(values[0]); } catch (ParseException e) { continue; } catch (RuntimeException e) { continue; } } log.debug("can not format date string:" + values[0]); return null; } /* * (non-Javadoc) * * @see org.apache.struts2.util.StrutsTypeConverter#convertToString(java.util.Map, * java.lang.Object) */ @Override public String convertToString(Map context, Object o) { if (o instanceof Date) { SimpleDateFormat format = new SimpleDateFormat( DEFAULT_DATE_FORMAT); try { return format.format((Date) o); } catch (RuntimeException e) { return ""; } } return ""; } }
这样,从字符串转换为日期对象的时候,会尝试上面列出的多种日期格式,但输出的时候,则会统一按照DEFAULT—DATE—FORMAT转换。 需要修改格式,只需要修改DEFAULT—DATE—FORMAT。当然,你也可以把它方在配置文件里,便于修改。
了解了这一点,其实也就 明白了struts的类型转换模式。然后,无论是字符串id到持久化对象的转换,还是自定义的字符串到对象之间的转换,都容易了。