JAVA生成图片验证码API

 效果图:




/**
* 生成JPG格式的图片验证验证码,存入图片缓冲区BufferedImage
*
* @author YangBin
*/
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Random;
class CodeImage {
private int height = 35;
private int width = 70;
private int num = 4;
private int fontSize = 15;
private StringBuilder sb = new StringBuilder();
private String[] fontName = {"宋体","华文楷体","黑体","微软雅黑"};
Random rd = new Random();

/**
* @return 获取当前二维码图片的长度
*/
public int getWidth() {
return width;
}
/**
* @param 设置二维码图片的长度
*/
public void setWidth(int width) {
this.width = width;
}
/**
* @return 获取当前二维码图片的高度
*/
public int getHeight() {
return height;
}
/**
* @param heigh 设置二维码图片的高度
*/
public void setHeight(int height) {
this.height = height;
}
/**
* @return 返回二维码字符个数
*/
public int getNum() {
return num;
}
/**
* @param num 设置二维码的字符个数.
*/
public void setNum(int num) {
this.num = num;
}
/**
* @return 当前二维码字体的大小
*/
public int getFontSize() {
return fontSize;
}
/**
* @param 获取二维码字体大小
*/
public void setFontSize(int fontSize) {
this.fontSize = fontSize;
}
/**
* @return 返回当前生成的二维码的内容
*/
public String getText(){
return sb.toString();
}

/**
* @return 返回一个图片缓冲区对象 BufferedImage 包含了绘制完成的图片.
*/
public BufferedImage getBufferedImage () {
BufferedImage bi = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
Graphics2D g = (Graphics2D)bi.getGraphics();
g.setColor(Color.WHITE);
g.fillRect(0, 0, width, height);
sb.delete(0, num);
for(int i=0;i<num;i++ ){
g.setColor(getColor());
g.setFont(getFont());
randomLine(g);
String s = getStr();
sb.append(s);
g.drawString(s, i*(width/num), height/2+rd.nextInt(height/2));
}
return bi;
}

/**
* @return 一个随机颜色的Color
*/
public Color getColor() {
return new Color(rd.nextInt(255),rd.nextInt(255),rd.nextInt(255));
}

/**
* @return 一个随记的数字或者字母
*/
public String getStr() {
String s = "23456789abcdefghigkmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
String ch = String.valueOf(s.charAt(rd.nextInt(s.length())));
return ch;
}

/**
* 绘制一条任意的线
* @param 画笔对象
*/
public void randomLine(Graphics2D g) {
int ax = rd.nextInt(width), ay = rd.nextInt(height);
int bx = rd.nextInt(width), by = rd.nextInt(height);
g.drawLine(ax, ay, bx, by);
}

/**
* @return 返回一个字体大小和字体随记.
*/
public Font getFont() {
return new Font(fontName[rd.nextInt(fontName.length)],rd.nextInt(4),rd.nextInt(10)+fontSize);
}
}


测试:将生成的图片写入的本地磁盘
public class CreatImage {

/*
* 创建图片;
*/
public static void main(String[] args) {
/*
* Image / ImageIo / BufferedImage / Icon / ImageIcon
*/
CodeImage c = new CodeImage();

BufferedImage bi = c.getBufferedImage();

System.out.println(c.getText());
try {

ImageIO.write(bi, "JPG", new FileOutputStream("E:/abc.jpg"));

} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
}