一、本图片生成器具有以下功能特性：

1、可以设置图片的宽度、高度、外框颜色、背景色；

2、可以设置图片字体的大小、名称、颜色；

3、可以设置输出图片的格式，如JPEG、GIF等；

4、可以将图片存储到一个文件或者存储到一个输出流；

5、可以为图片增加若干条干扰线(在生成随机码图片时可用此特性)；

6、打印在图片上的文字支持自动换行；

7、可以将文字旋转指定弧度数；

二、下面列出相关的源代码

1、抽象类AbstractImageCreator的源代码

/**

* 模板方法模式应用：图片生成器

*/

public abstract class AbstractImageCreator {

private static Random rnd = new Random(new Date().getTime());

private Drawer drawer;

//图片宽度

private int width = 200;

//图片高度

private int height = 80;

//外框颜色

private Color rectColor;

//背景色

private Color bgColor;

//干扰线数目

private int lineNum = 0;

//图片格式

private String formatName = "JPEG";

//字体颜色

private Color fontColor = new Color(0, 0, 0);

//字体名称

private String fontName = "宋体";

//字体大小

private int fontSize = 15;

//文字旋转的弧度数

private double radian = 0;

private double rotateX = 0;

private double rotateY = 0;

//缩放

private double scale = 1;

//##### 此处省略getter、setter方法 #####

public AbstractImageCreator(Drawer drawer){

this.drawer = drawer;

}

/**

* 画干扰线

*/

private void drawRandomLine(Graphics graph){

for(int i=0;i

//线条的颜色

graph.setColor(getRandomColor(100, 155));

//线条两端坐标值

int x1 = rnd.nextInt(width);

int y1 = rnd.nextInt(height);

int x2 = rnd.nextInt(width);

int y2 = rnd.nextInt(height);

//画线条

graph.drawLine(x1, y1, x2, y2);

}

}

/**

* 随机获取颜色对象

*/

private Color getRandomColor(int base, int range){

if((base + range) > 255) range = 255 - base;

int red = base + rnd.nextInt(range);

int green = base + rnd.nextInt(range);

int blue = base + rnd.nextInt(range);

return new Color(red, green, blue);

}

public void generateImage(String text)throws IOException{

BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

if(rectColor == null) rectColor = new Color(0, 0, 0);

if(bgColor == null) bgColor = new Color(240, 251, 200);

//获取画布

Graphics2D g = (Graphics2D)image.getGraphics();

//画长方形

g.setColor(bgColor);

g.fillRect(0, 0, width, height);

//外框

g.setColor(rectColor);

g.drawRect(0, 0, width-1, height-1);

//画干扰线

drawRandomLine(g);

//画字符串

drawer.draw(this, g, text);

//执行

g.dispose();

//输出图片结果

saveImage(image);

}

protected abstract void saveImage(BufferedImage image)throws IOException;

}

2、类FileImageCreator的源代码

该类将生成的图片存储到一个文件中，需要设置fileName成员变量值，该成员变量值表示图片的存储全路径。

public class FileImageCreator extends AbstractImageCreator {

private String fileName;

public String getFileName() {

return fileName;

}

public void setFileName(String fileName) {

this.fileName = fileName;

}

public FileImageCreator(Drawer drawer){

super(drawer);

}

public FileImageCreator(Drawer drawer, String fileName){

super(drawer);

this.fileName = fileName;

}

@Override

protected void saveImage(BufferedImage image)throws IOException{

ImageIO.write(image, getFormatName(), new File(fileName));

}

}

3、类StreamImageCreator的源代码

该类将生成的图片存储到一个输出流中，需要设置stream成员变量值。

public class StreamImageCreator extends AbstractImageCreator {

private OutputStream stream;

public OutputStream getStream() {

return stream;

}

public void setStream(OutputStream stream) {

this.stream = stream;

}

public StreamImageCreator(Drawer drawer){

super(drawer);

}

public StreamImageCreator(Drawer drawer, OutputStream stream){

super(drawer);

this.stream = stream;

}

@Override

protected void saveImage(BufferedImage image) throws IOException {

ImageIO.write(image, getFontName(), stream);

}

}

4、Drawer接口源码

public interface Drawer {

/**

* 在绘画板上绘制字符串

*

* @param creator 图片创建器对象

* @param g 绘画板

* @param text 待绘制的字符串

*/

public void draw(AbstractImageCreator creator, Graphics2D g, String text);

}

5、SimpleDrawer类源码

public class SimpleDrawer implements Drawer {

public void draw(AbstractImageCreator creator, Graphics2D g, String text){

//文字旋转

g.rotate(Math.toRadians(creator.getRadian()), creator.getRotateX(), creator.getRotateY());

g.scale(creator.getScale(), creator.getScale());

g.setColor(creator.getFontColor());

Font font = new Font(creator.getFontName(), Font.PLAIN, creator.getFontSize());

g.setFont(font);

FontMetrics fm = g.getFontMetrics(font);

int fontHeight = fm.getHeight(); //字符的高度

int offsetLeft = 0;

int rowIndex = 1;

for(int i=0;i

char c = text.charAt(i);

int charWidth = fm.charWidth(c); //字符的宽度

//另起一行

if(Character.isISOControl(c) || offsetLeft >= (creator.getWidth()-charWidth)){

rowIndex++;

offsetLeft = 0;

}

g.drawString(String.valueOf(c), offsetLeft, rowIndex * fontHeight);

offsetLeft += charWidth;

}

}

}

三、实例代码

public class Test {

public static void main(String[] args) {

try{

StringBuffer sb = new StringBuffer();

sb.append("中华人民共和国\n");

sb.append("中华人民共和国\n");

FileImageCreator creator = new FileImageCreator(new SimpleDrawer(), "c:\\img.jpeg");

creator.setWidth(150); //图片宽度

creator.setHeight(100); //图片高度

creator.setLineNum(20); //干扰线条数

creator.setFontSize(18); //字体大小

creator.setFontName("黑体");

//文字旋转

creator.setRadian(30.0); //旋转弧度

creator.setRotateX(creator.getWidth()/5);

creator.setRotateY(creator.getHeight()*5/10);

creator.generateImage(sb.toString());

System.out.println("ok");

}catch(IOException ex){

ex.printStackTrace();

}

}

}

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2011-12-16 15:32

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