struts2实现图片验证码

 

action

Java代码

package com.comm.validateNumImage.action;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
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 com.comm.action.BaseAction;

public class ValidateNumImageManagerAction extends BaseAction {
	private ByteArrayInputStream inputStream;  
    
    public String getValidateImage() throws Exception{ 
    	char[] mapTable = { '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' };
    	
//      在内存中创建图象   
    	int width=60, height=20;   
    	BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);

    	//
    	Graphics2D g = image.createGraphics();
	
    	// 填充背景色
    	g.setColor(Color.white);
    	g.fillRect(0, 0, width, height);
	
    	// 绘制边框
    	g.setColor(Color.BLACK);
    	g.drawRect(0, 0, width - 1, height - 1);
		
		 // 验证码
    	String security = "";
    	
    	// 随机生成验证码
    	Random random = new Random();
    	for (int i = 0; i < 4; i++) {
	        security += mapTable[random.nextInt(mapTable.length)];
    	}
	
    	// 绘制验证码
    	g.setColor(Color.BLACK);
    	g.setFont(new Font("MS Sans Serif", Font.PLAIN, 18));
	
    	String temp = security.substring(0, 1);
    	g.drawString(temp, 7, 15);
    	temp = security.substring(1, 2);
    	g.drawString(temp, 18, 17);
    	temp = security.substring(2, 3);
    	g.drawString(temp, 28, 18);
    	temp = security.substring(3, 4);
    	g.drawString(temp, 40, 17);
	
    	// 绘制干扰点
    	g.setColor(Color.BLACK);
    	for (int i = 0; i < 20; i++) {
	        g.drawOval(random.nextInt(width), random.nextInt(height), 0, 0);
    	}
    	g.dispose(); 
    	
    	this.getRequest().getSession().setAttribute("security", security);
    	ByteArrayOutputStream output = new ByteArrayOutputStream();   
    	ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);   
    	ImageIO.write(image, "JPEG", imageOut);   
    	imageOut.close();   
    	ByteArrayInputStream input = new ByteArrayInputStream(output.toByteArray());   
    	this.setInputStream(input);   
    	return SUCCESS;   
    }

    public void setInputStream(ByteArrayInputStream inputStream) {   
        this.inputStream = inputStream;   
    }   
    public ByteArrayInputStream getInputStream() {   
        return inputStream;   
    }
}

 

action 配置

Xml代码

 

<action name="getValidateImage" class="validateNumImageManagerAction" method="getValidateImage">   
	<result type="stream">   
		<param name="contentType">image/jpeg</param>   
		 <param name="inputName">inputStream</param>   
	</result>   
</action>  

 

js

<script type="text/javascript">
    function changeValidateCode(obj) {
           //获取当前的时间作为参数，无具体意义
        var timenow = new Date().getTime();
           //每次请求需要一个不同的参数，否则可能会返回同样的验证码
        //这和浏览器的缓存机制有关系，也可以把页面设置为不缓存，这样就不用这个参数了。
        obj.src="getValidateImage.action?d="+timenow;
    }
</script>

<img src="getValidateImage.action" onclick="changeValidateCode(this)"/>