<script language="javascript" type="text/javascript">
function reloadImage(imgurl){
var getimagecode=document.getElementById("codeimg");
getimagecode.src= imgurl + "?id=" + Math.random();
}
</script>
jsp調用js、strut中的rand.action 代碼是我自己編寫的，如果copy 特別要注意路徑問題
<td height="35" width="20%"> <span class="login_txt STYLE1">驗證碼：</span> </td> <td height="35" colspan="2" class="top_hui_text"> <input type="text" class="wenbenkuang" id="code" name="code" maxlength="4" size="20">
<img border="0" id="codeimg" name="codeimg" src="../rand.action">
<a href="javascript:reloadImage('../rand.action')"><font color="red">看不清</font></a><br>
</td>
接下來就是rand.action
package com.hz.bbs.action;
import java.io.ByteArrayInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
import com.hz.bbs.util.RandomNumUtil;
import com.opensymphony.xwork2.ActionSupport;
@SuppressWarnings("serial")
public class RandomAction extends ActionSupport{
private ByteArrayInputStream inputStream;
public String execute() throws Exception{
RandomNumUtil rdnu=RandomNumUtil.Instance();
this.setInputStream(rdnu.getImage());//取得帶有隨機字符串的圖片
String str = rdnu.getString().toString();
HttpServletRequest request = ServletActionContext.getRequest();
HttpSession session = request.getSession();
session.setAttribute("randoms", str);//取得隨機字符串放入HttpSession
return SUCCESS;
}
public void setInputStream(ByteArrayInputStream inputStream) {
this.inputStream = inputStream;
}
public ByteArrayInputStream getInputStream() {
return inputStream;
}
}
大家一定會覺得 那麼生產驗證碼的圖片 寫在那裏呢？別急，下面就是，我也是在網上copy的 只是拿來改改了
package com.hz.bbs.util;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
public class RandomNumUtil {
private ByteArrayInputStream image;//圖像
private String str;//驗證碼
//驗證碼序列。
private static final char[] randomSequence = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
'U', 'V', 'W', 'X', 'Y', 'Z', '0','1', '2', '3', '4', '5', '6',
'7','8', '9' };
private RandomNumUtil(){
init();//初始化屬性
}
public static RandomNumUtil Instance(){
return new RandomNumUtil();
}
public ByteArrayInputStream getImage(){
return this.image;
}
public String getString(){
return this.str;
}
private void init() {
// 在內存中創建圖象
int width=60, height=20;
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(200,250));
g.fillRect(0, 0, width, height);
//創建字體，字體的大小應該根據圖片的高度來定。
Font font = new Font("Times New Roman", Font.PLAIN, height-2);
//設置字體。
g.setFont(font);
//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<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(6位數字)
String sRand="";
for (int i=0;i<4;i++ ){
int index = random.nextInt(35);
String rand = String.valueOf(randomSequence[index]);
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
g.drawString(rand, 13 * i + 6, 16);
}
this.str=sRand;
// 圖象生效
g.dispose();
ByteArrayInputStream input=null;
ByteArrayOutputStream output = new ByteArrayOutputStream();
try{
ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);
ImageIO.write(image, "JPEG", imageOut);
imageOut.close();
input = new ByteArrayInputStream(output.toByteArray());
}catch(Exception e){
System.out.println("驗證碼圖片產生出現錯誤："+ e.toString());
}
this.image=input;
}
private 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);
}
}
最後一步，就是配置strut.xml了
<action name="rand" class="com.hz.bbs.action.RandomAction">
<result type="stream">
<param name="contentType">image/jpeg</param>
<param name="inputName">inputStream</param>
</result>
</action>
好了 大功告成了 呵呵
圖片展示：