Example Code

How to Draw Vertical Text in Java

examplecode — Fri, 05 Feb 2010 20:40:16 +0000

Import the AffineTransform class (in addition to the other awt classes that you are using):

import java.awt.geom.AffineTransform;

Get your graphics context:

Graphics2D g2d = ...;

Create a transform:

int degrees = -90; // rotate text counter-clockwise AffineTransform at = AffineTransform.getRotateInstance(Math.toRadians(degrees));

Create a new Font or use the existing Font from the Graphics context:

Font f = new Font("Arial", Font.BOLD, 12); g2d.setFont(f.deriveFont(at));

g2d.setFont((g2d.getFont()).deriveFont(at));

How to Draw a Dotted (or Dashed) Line in Java

examplecode — Wed, 03 Feb 2010 00:48:44 +0000

Need to create a Stroke object (such as BasicStroke). The API specifies a BasicStroke constructor:

BasicStroke(float width, int cap, int join, float miterlimit, float[] dash, float dash_phase)

The dash parameter is the one that defines the line pattern.
The float array contains “The definition of how to make a dash pattern by alternating between opaque and transparent sections.”
So if the array were defined as:

new float[] {4,2,8,2}

The line would start off drawing 4 pixels (opaque), then skip 2 pixels (transparent), then draw 8 pixels (opaque), then skip 2 more pixels (transparent), then repeat for the remainder of the line.

If the float array only contained one value:

new float[] {10}

Then the line would simply alternate between opaque and transparent pixels of the specified value. In this case, it would draw 10 pixels, skip 10 pixels, draw 10 pixels, skip 10 pixels, etc.

Here is a fully constructed sample of a dotted line:

Stroke dotted = new BasicStroke(1, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL, 0, new float[] {1,2}, 0);

For more info, see:
http://java.sun.com/javase/6/docs/api/java/awt/BasicStroke.html

Reusing Password in Oracle

examplecode — Tue, 02 Feb 2010 17:55:59 +0000

First, sqlplus into the database as user sys.

Then find the unique id of the user that you want to change the password for from the dba_users table:

SELECT username, user_id FROM dba_users WHERE username='MYUSER' /

USERNAME USER_ID ------------ ---------- MYUSER 42

Then delete the user’s password history from the user_history$ table where the user# field contains the user_id value returned in the previous step:

DELETE FROM user_history$ WHERE user#=42 /

Creating Image Files in Java Using ImageIO

examplecode — Tue, 12 Jan 2010 00:39:29 +0000

import java.awt.image.BufferedImage; import java.awt.Graphics2D; import java.io.File; import javax.imageio.ImageIO; import java.io.IOException;


int width = 800;

int height = 600;

BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);

Graphics2D g2d = bufferedImage.createGraphics();
// draw graphics
g2d.dispose();
try {
  // Save as PNG

  File file = new File("newimage.png");

  ImageIO.write(bufferedImage, "png", file);
  // Save as JPEG

  file = new File("newimage.jpg");

  ImageIO.write(bufferedImage, "jpg", file);

} catch (IOException e) { }

For more info, see:

http://www.exampledepot.com/egs/javax.imageio/Graphic2File.html

Masked Password Prompt from Text Console in Java

examplecode — Tue, 12 Jan 2010 00:18:22 +0000

Console console = System.console(); String username = console.readLine("Enter USERNAME: "); char[] password = console.readPassword("Enter PASSWORD: "); conn = DriverManager.getConnection(url, username, new String(password)); Arrays.fill(password, ' ');

For more info, see:

http://java.sun.com/developer/technicalArticles/Security/pwordmask/

Connecting to an Oracle Database Using Oracle Thin JDBC Driver

examplecode — Mon, 11 Jan 2010 23:55:10 +0000

Note: Do NOT include square brackets around text values in “url” string below.

String url = "jdbc:oracle:thin:@[server]:[port]:[ORACLE_SID]";


try {

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

}  catch (ClassNotFoundException e) { }

Connection conn = DriverManager.getConnection(url, username, password);