out.clear();
out = pageContext.pushBody();
原文件是這樣寫的:
<%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,java.io.*,javax.imageio.*" %>
<%!
//給定范圍獲得隨機顏色
Color getRandColor(int fc,int bc)
{
??????? 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);
}
%>
<%
//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=60, height=16;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
// 獲取圖形上下文
Graphics g = image.getGraphics();
//生成隨機類
Random random = new Random();
// 設定背景色
g.setColor(getRandColor(150,160));
g.fillRect(0, 0, width, height);
//設定字體
g.setFont(new Font("Times New Roman",Font.PLAIN,18));
//畫邊框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 隨機產生155條干擾線,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<155;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 rand = request.getParameter("rand");
//rand = rand.substring(0,rand.indexOf("."));
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,可能是因為種子太接近,所以只能直接生成
??? g.drawString(rand,13*i+6,16);
}
// 將認證碼存入SESSION
session.setAttribute("CerCode",sRand);
// 圖象生效
g.dispose();
// 輸出圖象到頁面
OutputStream os=response.getOutputStream();
ImageIO.write(image, "JPEG", os);
%>
我改過的文件:
<%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,java.io.*,javax.imageio.*" %>
<%!
//給定范圍獲得隨機顏色
Color getRandColor(int fc,int bc)
{
??????? 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);
}
%>
<%
try{
//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=60, height=16;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
// 獲取圖形上下文
Graphics g = image.getGraphics();
//生成隨機類
Random random = new Random();
// 設定背景色
g.setColor(getRandColor(150,160));
g.fillRect(0, 0, width, height);
//設定字體
g.setFont(new Font("Times New Roman",Font.PLAIN,18));
//畫邊框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 隨機產生155條干擾線,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<155;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 rand = request.getParameter("rand");
//rand = rand.substring(0,rand.indexOf("."));
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,可能是因為種子太接近,所以只能直接生成
??? g.drawString(rand,13*i+6,16);
}
// 將認證碼存入SESSION
session.setAttribute("CerCode",sRand);
// 圖象生效
g.dispose();
// 輸出圖象到頁面
OutputStream os=response.getOutputStream();
ImageIO.write(image, "JPEG", os);
os.flush();
os.close();
os=null;
response.flushBuffer();
out.clear();
out = pageContext.pushBody();
}catch(IllegalStateException e)
{
System.out.println(e.getMessage());
e.printStackTrace();
}finally{
}
%>
問題解決(紅色為加的代碼)