package cn.com; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; 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 ResponseDemoRandom extends HttpServlet { private static final long serialVersionUID = 1L; public static final int WIDTH=120; public static final int HEIGHT=25; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { BufferedImage image=new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB); Graphics g=image.getGraphics(); //设置背景色 setBackGround(g); //设置边框 setBorder(g); //画干扰线 drawRandomLine(g); //写随机数 drawRandomNum((Graphics2D)g); response.setContentType("image/jpeg"); response.setDateHeader("expries", -1); response.setHeader("Cache-Control", "no-control"); response.setHeader("prama", "no-control"); ImageIO.write(image, "jpg", response.getOutputStream()); } private void drawRandomNum(Graphics2D g) { g.setColor(Color.PINK); g.setFont(new Font("宋体",Font.BOLD,20)); int x=10; for(int i=0;i<4;i++) { int degree=new Random().nextInt()%30; int num=new Random().nextInt(9); String str=num+""; g.rotate(degree*Math.PI/180, x, 20); g.drawString(str, x, 20); g.rotate(-degree*Math.PI/180, x, 20); x+=30; } } private void drawRandomLine(Graphics g) { g.setColor(Color.blue); for(int i=0;i<5;i++) { int x1=new Random().nextInt(WIDTH-4)+2; int y1=new Random().nextInt(HEIGHT-4)+2; int x2=new Random().nextInt(WIDTH-2); int y2=new Random().nextInt(HEIGHT-2); g.drawLine(x1, y1, x2, y2); } } private void setBorder(Graphics g) { g.setColor(Color.GREEN); g.drawRect(1, 1, WIDTH-2, HEIGHT-2); } private void setBackGround(Graphics g) { g.setColor(Color.gray); g.fillRect(0, 0, WIDTH, HEIGHT); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request,response); } }