如何在Android中对日期和空日期进行排序？

我得到JSON数据，我想我得到日期和nulldate存储在arrylist.how排序日期和空日期数据设置在列表视图排序日期在下面。我将所有数据存储在All_Approval_data_dto类中。我的代码如下：请检查它，我错过了什么？如何在Android中对日期和空日期进行排序？

static final Comparator<All_Approval_data_dto> byDate = new Comparator<All_Approval_data_dto>() { 
     SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss a"); 

     public int compare(All_Approval_data_dto ord1, 
       All_Approval_data_dto ord2) { 

      java.util.Date d1 = null; 
      java.util.Date d2 = null; 
      try { 
       d1 = sdf.parse(ord1.lastModifiedDate); 
       d2 = sdf.parse(ord2.lastModifiedDate); 
       if (d1 == null) { 
        return (d2 == null) ? 0 : -1; 
       } 
       if (d2 == null) { 
        return 1; 
       } 

      } catch (java.text.ParseException e) { 
       // TODO Auto-generated catch block` 
       e.printStackTrace(); 
      } 

      return (d1.getTime() > d2.getTime() ? -1 : 1); // descending 
      // return (d1.getTime() > d2.getTime() ? 1 : -1); //ascending 
     } 

    };

我在下面的错误：

11-02 11:03:58.861: ERROR/AndroidRuntime(473): FATAL EXCEPTION: main 
11-02 11:03:58.861: ERROR/AndroidRuntime(473): java.lang.NullPointerException 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1201) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.text.DateFormat.parse(DateFormat.java:642) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at com.serana.Approval$2.compare(Approval.java:155) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at com.serana.Approval$2.compare(Approval.java:1) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.util.TimSort.countRunAndMakeAscending(TimSort.java:320) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.util.TimSort.sort(TimSort.java:185) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.util.TimSort.sort(TimSort.java:169) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.util.Arrays.sort(Arrays.java:1907) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.util.Collections.sort(Collections.java:1972) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at com.serana.Approval$4.onItemSelected(Approval.java:79) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at android.widget.AdapterView.fireOnSelected(AdapterView.java:864) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at android.widget.AdapterView.access$200(AdapterView.java:42) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:830) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at android.os.Handler.handleCallback(Handler.java:587) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at android.os.Handler.dispatchMessage(Handler.java:92) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at android.os.Looper.loop(Looper.java:123) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at android.app.ActivityThread.main(ActivityThread.java:4627) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.lang.reflect.Method.invokeNative(Native Method) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at java.lang.reflect.Method.invoke(Method.java:521) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
11-02 11:03:58.861: ERROR/AndroidRuntime(473):  at dalvik.system.NativeStart.main(Native Method)

来源

2012-11-02 crickpatel0024

请帮帮我!!!!!!!!!!!!! – crickpatel0024

请使用此代码

try { 

      if (d1 == null) { 
       return (d2 == null) ? 0 : -1; 
      } 
      if (d2 == null) { 
       return 1; 
      } 

      d1 = sdf.parse(ord1.lastModifiedDate); 
      d2 = sdf.parse(ord2.lastModifiedDate); 

     } catch (java.text.ParseException e) { 
      // TODO Auto-generated catch block` 
      e.printStackTrace(); 
     }

取代你的try/catch块

来源

2012-11-02 06:41:40

不行你的代码jignesh !!! 1 – crickpatel0024

-更好地利用Joda库进行比较的日期。

-首先你需要解析它们。使用DateTimeFormat：

DateTimeFormatter fmt = DateTimeFormat.forPattern("yyyy-MM-dd"); 
DateTime dateTime1 = fmt.parseDateTime(string1);

-然后使用DateTime.isBefore（..）方法对它们进行比较：

if (dateTime1.isBefore(dateTime2))

来源

2012-11-02 05:46:53

好的一个vivek。 –

但是我想要DateTimeFormatter Add in方法。 – crickpatel0024

@iDroidExplorer谢谢..... –

如何在Android中对日期和空日期进行排序？

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