Java实现的图片生成器

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<lineNum;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<text.length();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();
		}
	}
}