необработанное исключение: Ошибка java.lang.ClassNotFoundException

Question

У меня есть следующий код класса и при отладки он продолжал показывать следующее сообщение об ошибке:

1.) Необработанное исключение: java.lang.ClassNotFoundException 2.) Необработанное исключение: java.lang.NoSuchMethodException

Журнал ошибок:

/apps/robotapp/Utils.java:32: error: exception IOException is never thrown in body of corresponding try statement 
    } catch (IOException e) { 
    ^
/apps/robotapp/Utils.java:24: error: unreported exception ClassNotFoundException; must be caught or declared to be thrown 
     final int tckName = Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null); 
             ^
/apps/robotapp/Utils.java:24: error: unreported exception NoSuchFieldException; must be caught or declared to be thrown 
     final int tckName = Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null); 
                      ^
/apps/robotapp/Utils.java:24: error: unreported exception IllegalAccessException; must be caught or declared to be thrown 
     final int tckName = Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null); 
                           ^
/apps/robotapp/Utils.java:25: error: unreported exception ClassNotFoundException; must be caught or declared to be thrown 
     final Object os = Class.forName("libcore.io.Libcore").getField("os").get(null); 
            ^
/apps/robotapp/Utils.java:25: error: unreported exception NoSuchFieldException; must be caught or declared to be thrown 
     final Object os = Class.forName("libcore.io.Libcore").getField("os").get(null); 
                    ^
/apps/robotapp/Utils.java:25: error: unreported exception IllegalAccessException; must be caught or declared to be thrown 
     final Object os = Class.forName("libcore.io.Libcore").getField("os").get(null); 
                       ^
/apps/robotapp/Utils.java:26: error: unreported exception NoSuchMethodException; must be caught or declared to be thrown 
     final long tck = (Long)os.getClass().getMethod("sysconf", Integer.TYPE).invoke(os, tckName); 
                ^
/apps/robotapp/Utils.java:26: error: unreported exception IllegalAccessException; must be caught or declared to be thrown 
     final long tck = (Long)os.getClass().getMethod("sysconf", Integer.TYPE).invoke(os, tckName); 



^
Note:   
/RobotService.java uses or overrides a deprecated API. 
    Note: Recompile with -Xlint:deprecation for details. 
    9 errors 

    FAILED 

фрагмент кода, который имеет ошибки:

try { 
     final String[] fields = stat.substring(stat.lastIndexOf(field2End)).split(fieldSep); 
     final long t = Long.parseLong(fields[fieldStartTime]); 
     final int tckName = Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null); 
     final Object os = Class.forName("libcore.io.Libcore").getField("os").get(null); 
     final long tck = (Long)os.getClass().getMethod("sysconf", Integer.TYPE).invoke(os, tckName); 
     return t * msInSec/tck; 
    } catch (final NumberFormatException e) { 
     throw new IOException(e); 
    } catch (final IndexOutOfBoundsException e) { 
     throw new IOException(e); 
    } catch (IOException e) { 
     throw new IOException(e); 
    } 

Answer 1

Вы должны добавить все ваши исключения или использовать улов все:

try { 
} catch(Exception exp) { } 

Ваш код после исправления:

try { 
    final String[] fields = stat.substring(stat.lastIndexOf(field2End)).split(fieldSep); 
    final long t = Long.parseLong(fields[fieldStartTime]); 
    final int tckName = Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null); 
    final Object os = Class.forName("libcore.io.Libcore").getField("os").get(null); 
    final long tck = (Long)os.getClass().getMethod("sysconf", Integer.TYPE).invoke(os, tckName); 
    return t * msInSec/tck; 
} catch (final NumberFormatException e) { 
    throw new IOException(e); 
} catch (final IndexOutOfBoundsException e) { 
    throw new IOException(e); 
} catch (java.lang.ClassNotfoundException e) { 
    throw new IOException(e); 
} catch (java.lang.NoSuchMethodException e) { 
    throw new IOException(e); 
} catch (IllegalAccessException e) { 
    throw new IOException(e); 
} 

Кроме того, IOException вы ловли, удаляется, так как она (по отладчик) никогда не бросали.

Answer 2

Изменить код на

try { 
    //do something 
} catch (Exception e) { 
    e.printStackTrace(); 
    //throw new Exception("Error occured"); 
} 

или

try { 
    final String[] fields = stat.substring(stat.lastIndexOf(field2End)).split(fieldSep); 
    final long t = Long.parseLong(fields[fieldStartTime]); 
    final int tckName = Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null); 
    final Object os = Class.forName("libcore.io.Libcore").getField("os").get(null); 
    final long tck = (Long)os.getClass().getMethod("sysconf", Integer.TYPE).invoke(os, tckName); 
    return t * msInSec/tck; 
} catch (ClassNotFoundException|NoSuchFieldException|IllegalAccessException|NoSuchMethodException e) { 
    throw e; 
} 

Намного чище, верно?