ru_java, posts by tag: tips - LiveJournal (original) (raw)

Как в JDK 1.6 реализован SQLException.iterator() и как это можно упростить

unix_junkie

June 25th, 2007

Начиная с 1.6, SQLException реализует Iterable; подробности здесь.

**public** Iterator<Throwable> iterator() {

   **return** **new** Iterator<Throwable>() {

       SQLException firstException = SQLException.**this**;
       SQLException nextException =
           firstException.getNextException();
       Throwable cause = firstException.getCause();

       **public** **boolean** hasNext() {
           **if**(firstException != null || nextException != null
                   || cause != null)
               **return** true;
           **return** false;
       }

       **public** Throwable next() {
           Throwable throwable = null;
           **if**(firstException != null){
               throwable = firstException;
               firstException = null;
           }
           **else** **if**(cause != null){
               throwable = cause;
               cause = cause.getCause();
           }
           **else** **if**(nextException != null){
               throwable = nextException;
               cause = nextException.getCause();
               nextException = nextException.getNextException();
           }
           **else**
               **throw** **new** NoSuchElementException();
           **return** throwable;
       }

       **public** **void** remove() {
           **throw** **new** UnsupportedOperationException();
       }

   };

}

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[Tip of the day][Очередное извращение] Return a Property Without System.getProperty

smesh

June 11th, 2004

Return a Property Without System.getProperty

On the JVM, System.getProperty()will only return a property if that property has been set using the -D flag. But what if a property has been set using EXPORT on a UNIX platform? Use this code to return the property:

Process p = null;
                try
                {
                        p = Runtime.getRuntime().exec("env");
                        java.util.Properties pr = new java.util.Properties();
                        pr.load(p.getInputStream());
                        System.out.println("Property : " + pr.getProperty(propName));
                }
                catch(Exception e)
                {
                        e.printStackTrace();
                }

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