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Java system properties and environment variables

...e=value syntax. They can also be added at runtime using System.setProperty(String key, String value) or via the various System.getProperties().load() methods. To get a specific system property you can use System.getProperty(String key) or System.getProperty(String key, String def). Environment varia...
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'0000-00-00 00:00:00' can not be represented as java.sql.Timestamp error

...k to the database. For 0000-00-00, I suggest checking the date value as a string, then changing it to ("y",1), or ("yyyy-MM-dd",0001-01-01), or into any invalid MySQL date (less than year 1000, iirc). MySQL has another "feature": low dates are automatically converted to 0000-00-00. I realize my su...
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How to cast List to List

...'s a more versatile solution: List<Object> objects = Arrays.asList("String1", "String2"); List<String> strings = objects.stream() .map(element->(String) element) .collect(Collectors.toList()); There's a ton of benefits, but one is that...
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Android AsyncTask testing with Android Test Framework

...ask you want to unit test in your project. */ final AsyncTask<String, Void, String> myTask = new AsyncTask<String, Void, String>() { @Override protected String doInBackground(String... arg0) { //Do something meaningful. return "something...
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How to get only time from date-time C# [closed]

...ns for this: DateTime dt = DateTime.Parse("6/22/2009 07:00:00 AM"); dt.ToString("HH:mm"); // 07:00 // 24 hour clock // hour is always 2 digits dt.ToString("hh:mm tt"); // 07:00 AM // 12 hour clock // hour is always 2 digits dt.ToString("H:mm"); // 7:00 // 24 hour clock dt.ToString("h:mm tt"); // 7...
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Array slicing in Ruby: explanation for illogical behaviour (taken from Rubykoans.com)

...s, so they are defined in such a way that the beginning and the end of the string have working zero-length expressions. array[4, 0] = :sandwich array[0, 0] = :crunchy => [:crunchy, :peanut, :butter, :and, :jelly, :sandwich] ...
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Postgresql - change the size of a varchar column to lower length

... other databases, is smart enough to only use just enough space to fit the string (even using compression for longer strings), so even if your column is declared as VARCHAR(255) - if you store 40-character strings in the column, the space usage will be 40 bytes + 1 byte of overhead. The storage ...
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Display number with leading zeros

...}".format(1)) For Python 3.6+ the same behavior can be achieved with f-strings: print(f"{1:02d}") share | improve this answer | follow | ...
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How can I convert ereg expressions to preg in PHP?

...$str); You can easily escape all delimiters and reserved characters in a string by using preg_quote: $expr = preg_quote('/hello', '/'); preg_match('/^'.$expr.'/', $str); Also, PCRE supports modifiers for various things. One of the most used is the case-insensitive modifier i, the alternative to...
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How to convert hex to rgb using Java?

...@param colorStr e.g. "#FFFFFF" * @return */ public static Color hex2Rgb(String colorStr) { return new Color( Integer.valueOf( colorStr.substring( 1, 3 ), 16 ), Integer.valueOf( colorStr.substring( 3, 5 ), 16 ), Integer.valueOf( colorStr.substring( 5, 7 ), 1...