Java Quick Programing Memo

template

public class Test {

    public static void main(String[] args) {

    }

}

initialize array

int[] intArray = new int[10];

char[] charArray = new char[size];

String[] stringArray = {"Sunday", "Monday", "Tuesday"};

Display

System.out.println("");

e.printStackTrace(System.err);

System.currentTimeMillis();

String

Integer.parseInt(String);

Integer.toOctalString(int);

String.toCharArray();

Integer.parseInt( "1100100", 2 );

Integer.toString( 100, 2);

Integer.toBinaryString( 100 );

Loop

for (int i = 0; i < args.length; i++) {

}

Thread

new Thread();

Thread.start();

Thread.getState() == Thread.State.TERMINATED

Thread.join();

Thread.sleep(10);

UTF-16

int  cp ;  // Unicode code point in Java integer       

Character.isLetter( cp ); // safe for non-BMP characters as well as BMP

int  n = s.codePointCount(0, s.length()); // n is the number of Unicode characters

Database

Class.forName("oracle.jdbc.OracleDriver");

DriverManager.getConnection(constr,username,password);

Connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);

Statement.executeQuery();

ResultSet.getMetaData();

PreparedStatement.addBatch();

PreparedStatement.executeBatch();

SAX

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

SAXParserFactory factory = SAXParserFactory.newInstance();

SAXParser parser = factory.newSAXParser();

parser.parse(InputSource, DefaultHandler);

public void startElement(String namespaceURI,

      String localName,

      String qName,

      Attributes atts) throws SAXException

m_tagstack.push(qName);

public void endElement(String namespaceURI,

      String localName,

      String qName) throws SAXException

m_tagstack.pop();

public void characters(char[] ch, int start, int length)

  throws SAXException

StringBuffer.append(new String(ch, start, length));

Bit

public class BitTest {

  static final int AGE = 1;

  static final int ADDRESS = 2;

  static final int SEX = 4;

  static final int OTHERS = 8;

  public static void main(String[] args) {

    int judge = 0;

    judge = judge | AGE;

    judge = judge | ADDRESS;

    if ((judge & AGE) == AGE) {

      if ((judge & ADDRESS) == ADDRESS) {

        System.out.println("Your age and address is OK");

      } else {

        System.out.println("Your address is NG");

      }

    } else {

      System.out.println("Your age is NG");

    }

  }

}