在struts2中驗證碼無法在action中生成,只能通過servlet來生成。
1、創建驗證碼servlet
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class RandCodeServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//設置頁面不緩存
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
// 在內存中創建圖象
int width=130, height=40;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
// 獲取圖形上下文
Graphics2D g = image.createGraphics();
//生成隨機類
Random random = new Random();
// 設定背景色
g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);
//設定字體
g.setFont(new Font("Fixedsys",Font.PLAIN,38));
//畫邊框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 隨機產生155條幹擾線,使圖象中的認證碼不易被其它程序探測到
g.setColor(getRandColor(160,200));
for (int i=0;i<255;i++){
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x,y,x+xl,y+yl);
}
// 取隨機產生的認證碼(4位數字)
String sRand="";
for (int i=0;i<4;i++){
String rand=String.valueOf(random.nextInt(10));
sRand+=rand;
// 將認證碼顯示到圖象中
g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
//調用函數出來的顏色相同,可能是因爲種子太接近,所以只能直接生成
rand += " ";
g.drawString(rand,30*i+16,36);
}
request.getSession().setAttribute("YZM",sRand);
// 圖象生效
g.dispose();
// 輸出圖象到頁面
ImageIO.write(image, "JPEG", response.getOutputStream());
response.getOutputStream().flush();
response.getOutputStream().close();
}
private static Color getRandColor(int fc,int bc){//給定範圍獲得隨機顏色
Random random = new Random();
if(fc>255) fc=255;
if(bc>255) bc=255;
int r=fc+random.nextInt(bc-fc);
int g=fc+random.nextInt(bc-fc);
int b=fc+random.nextInt(bc-fc);
return new Color(r,g,b);
}
}
2、web.xml配置
<servlet>
<servlet-name>RandCodeServlet</servlet-name>
<servlet-class>com.col.sesame.common.util.RandCodeServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RandCodeServlet</servlet-name>
<url-pattern>/RandCodeServlet</url-pattern>
</servlet-mapping>