java登录验证码实现代码
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2023-12-18 22:33:46
verifycodeservlet.java类：复制代码 代码如下:package com.spring.controller;import java.awt.color;...
verifycodeservlet.java类：
package com.spring.controller;
import java.awt.color;
import java.awt.font;
import java.awt.graphics2d;
import java.awt.image.bufferedimage;
import java.util.random;
import javax.imageio.imageio;
import javax.servlet.servletexception;
import javax.servlet.servletoutputstream;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import javax.servlet.http.httpsession;
import org.springframework.stereotype.controller;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.requestmethod;
@controller
public class verifycodeservlet extends httpservlet {
// 验证码图片的宽度。
private int width = 60;
// 验证码图片的高度。
private int height = 20;
// 验证码字符个数
private int codecount = 4;
private int x = 0;
// 字体高度
private int fontheight;
private int codey;
char[] codesequence = { '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' };
/**
* 初始化验证图片属性
*/
public void initxuan() throws servletexception {
// 从web.xml中获取初始信息
// 宽度
string strwidth ="80";
// 高度
string strheight ="30";
// 字符个数
string strcodecount = "4";
// 将配置的信息转换成数值
try {
if (strwidth != null && strwidth.length() != 0) {
width = integer.parseint(strwidth);
}
if (strheight != null && strheight.length() != 0) {
height = integer.parseint(strheight);
}
if (strcodecount != null && strcodecount.length() != 0) {
codecount = integer.parseint(strcodecount);
}
} catch (numberformatexception e) {
}
x = width / (codecount + 1);
fontheight = height - 2;
codey = height - 4;
}
@requestmapping(value="xuan/verifycode",method=requestmethod.get)
public void service(httpservletrequest req, httpservletresponse resp)
throws servletexception, java.io.ioexception {
initxuan();
// 定义图像buffer
bufferedimage buffimg = new bufferedimage(width, height,
bufferedimage.type_int_rgb);
graphics2d g = buffimg.creategraphics();
// 创建一个随机数生成器类
random random = new random();
// 将图像填充为白色
g.setcolor(color.white);
g.fillrect(0, 0, width, height);
// 创建字体，字体的大小应该根据图片的高度来定。
font font = new font("fixedsys", font.plain, fontheight);
// 设置字体。
g.setfont(font);
// 画边框。
g.setcolor(color.black);
g.drawrect(0, 0, width - 1, height - 1);
// 随机产生160条干扰线，使图象中的认证码不易被其它程序探测到。
g.setcolor(color.black);
for (int i = 0; i < 10; 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);
}
// randomcode用于保存随机产生的验证码，以便用户登录后进行验证。
stringbuffer randomcode = new stringbuffer();
int red = 0, green = 0, blue = 0;
// 随机产生codecount数字的验证码。
for (int i = 0; i < codecount; i++) {
// 得到随机产生的验证码数字。
string strrand = string.valueof(codesequence[random.nextint(36)]);
// 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同。
red = random.nextint(255);
green = random.nextint(255);
blue = random.nextint(255);
// 用随机产生的颜色将验证码绘制到图像中。
g.setcolor(new color(red, green, blue));
g.drawstring(strrand, (i + 1) * x, codey);
// 将产生的四个随机数组合在一起。
randomcode.append(strrand);
}
// 将四位数字的验证码保存到session中。
httpsession session = req.getsession();
session.setattribute("validatecode", randomcode.tostring());
// 禁止图像缓存。
resp.setheader("pragma", "no-cache");
resp.setheader("cache-control", "no-cache");
resp.setdateheader("expires", 0);
resp.setcontenttype("image/jpeg");
// 将图像输出到servlet输出流中。
servletoutputstream sos = resp.getoutputstream();
imageio.write(buffimg, "jpeg", sos);
sos.close();
}
}
resultservlet.java:
package com.spring.controller;
import java.io.ioexception;
import java.io.printwriter;
import javax.servlet.servletexception;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import org.springframework.stereotype.controller;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.requestmethod;
@controller
public class resultservlet {
@requestmapping(value="resultservlet/validatecode",method=requestmethod.post)
public void dopost(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
response.setcontenttype("text/html;charset=utf-8");
string validatec = (string) request.getsession().getattribute("validatecode");
string verycode = request.getparameter("c");
printwriter out = response.getwriter();
if(verycode==null||"".equals(verycode)){
out.println("验证码为空");
}else{
if(validatec.equals(verycode)){
out.println("验证码正确");
}else{
out.println("验证码错误");
}
}
out.flush();
out.close();
}
}
jsp页面：
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http://www.w3.org/tr/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>test verify code</title>
</head>
<body>
<input id="verycode" name="verycode" type="text"/>
<img id="imgobj" alt="" src="xuan/verifycode"/>
<a href="#" onclick="changeimg()">换一张</a>
<input type="button" value="验证" onclick="isrightcode()"/>
<div id="info"></div>
</body>
</html>
<script type="text/javascript">
function changeimg(){
var imgsrc = $("#imgobj");
var src = imgsrc.attr("src");
imgsrc.attr("src",chgurl(src));
}
//时间戳
//为了使每次生成图片不一致，即不让浏览器读缓存，所以需要加上时间戳
function chgurl(url){
var timestamp = (new date()).valueof();
urlurl = url.substring(0,17);
if((url.indexof("&")>=0)){
urlurl = url + "×tamp=" + timestamp;
}else{
urlurl = url + "?timestamp=" + timestamp;
}
return url;
}
function isrightcode(){
var code = $("#verycode").attr("value");
code = "c=" + code;
$.ajax({
type:"post",
url:"resultservlet/validatecode",
data:code,
success:callback
});
}
function callback(data){
$("#info").html(data);
}
</script>
运行效果：
复制代码 代码如下:
package com.spring.controller;
import java.awt.color;
import java.awt.font;
import java.awt.graphics2d;
import java.awt.image.bufferedimage;
import java.util.random;
import javax.imageio.imageio;
import javax.servlet.servletexception;
import javax.servlet.servletoutputstream;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import javax.servlet.http.httpsession;
import org.springframework.stereotype.controller;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.requestmethod;
@controller
public class verifycodeservlet extends httpservlet {
// 验证码图片的宽度。
private int width = 60;
// 验证码图片的高度。
private int height = 20;
// 验证码字符个数
private int codecount = 4;
private int x = 0;
// 字体高度
private int fontheight;
private int codey;
char[] codesequence = { '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' };
/**
* 初始化验证图片属性
*/
public void initxuan() throws servletexception {
// 从web.xml中获取初始信息
// 宽度
string strwidth ="80";
// 高度
string strheight ="30";
// 字符个数
string strcodecount = "4";
// 将配置的信息转换成数值
try {
if (strwidth != null && strwidth.length() != 0) {
width = integer.parseint(strwidth);
}
if (strheight != null && strheight.length() != 0) {
height = integer.parseint(strheight);
}
if (strcodecount != null && strcodecount.length() != 0) {
codecount = integer.parseint(strcodecount);
}
} catch (numberformatexception e) {
}
x = width / (codecount + 1);
fontheight = height - 2;
codey = height - 4;
}
@requestmapping(value="xuan/verifycode",method=requestmethod.get)
public void service(httpservletrequest req, httpservletresponse resp)
throws servletexception, java.io.ioexception {
initxuan();
// 定义图像buffer
bufferedimage buffimg = new bufferedimage(width, height,
bufferedimage.type_int_rgb);
graphics2d g = buffimg.creategraphics();
// 创建一个随机数生成器类
random random = new random();
// 将图像填充为白色
g.setcolor(color.white);
g.fillrect(0, 0, width, height);
// 创建字体，字体的大小应该根据图片的高度来定。
font font = new font("fixedsys", font.plain, fontheight);
// 设置字体。
g.setfont(font);
// 画边框。
g.setcolor(color.black);
g.drawrect(0, 0, width - 1, height - 1);
// 随机产生160条干扰线，使图象中的认证码不易被其它程序探测到。
g.setcolor(color.black);
for (int i = 0; i < 10; 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);
}
// randomcode用于保存随机产生的验证码，以便用户登录后进行验证。
stringbuffer randomcode = new stringbuffer();
int red = 0, green = 0, blue = 0;
// 随机产生codecount数字的验证码。
for (int i = 0; i < codecount; i++) {
// 得到随机产生的验证码数字。
string strrand = string.valueof(codesequence[random.nextint(36)]);
// 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同。
red = random.nextint(255);
green = random.nextint(255);
blue = random.nextint(255);
// 用随机产生的颜色将验证码绘制到图像中。
g.setcolor(new color(red, green, blue));
g.drawstring(strrand, (i + 1) * x, codey);
// 将产生的四个随机数组合在一起。
randomcode.append(strrand);
}
// 将四位数字的验证码保存到session中。
httpsession session = req.getsession();
session.setattribute("validatecode", randomcode.tostring());
// 禁止图像缓存。
resp.setheader("pragma", "no-cache");
resp.setheader("cache-control", "no-cache");
resp.setdateheader("expires", 0);
resp.setcontenttype("image/jpeg");
// 将图像输出到servlet输出流中。
servletoutputstream sos = resp.getoutputstream();
imageio.write(buffimg, "jpeg", sos);
sos.close();
}
}
resultservlet.java:
复制代码 代码如下:
package com.spring.controller;
import java.io.ioexception;
import java.io.printwriter;
import javax.servlet.servletexception;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import org.springframework.stereotype.controller;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.requestmethod;
@controller
public class resultservlet {
@requestmapping(value="resultservlet/validatecode",method=requestmethod.post)
public void dopost(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
response.setcontenttype("text/html;charset=utf-8");
string validatec = (string) request.getsession().getattribute("validatecode");
string verycode = request.getparameter("c");
printwriter out = response.getwriter();
if(verycode==null||"".equals(verycode)){
out.println("验证码为空");
}else{
if(validatec.equals(verycode)){
out.println("验证码正确");
}else{
out.println("验证码错误");
}
}
out.flush();
out.close();
}
}
jsp页面：
复制代码 代码如下:
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http://www.w3.org/tr/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>test verify code</title>
</head>
<body>
<input id="verycode" name="verycode" type="text"/>
<img id="imgobj" alt="" src="xuan/verifycode"/>
<a href="#" onclick="changeimg()">换一张</a>
<input type="button" value="验证" onclick="isrightcode()"/>
<div id="info"></div>
</body>
</html>
<script type="text/javascript">
function changeimg(){
var imgsrc = $("#imgobj");
var src = imgsrc.attr("src");
imgsrc.attr("src",chgurl(src));
}
//时间戳
//为了使每次生成图片不一致，即不让浏览器读缓存，所以需要加上时间戳
function chgurl(url){
var timestamp = (new date()).valueof();
urlurl = url.substring(0,17);
if((url.indexof("&")>=0)){
urlurl = url + "×tamp=" + timestamp;
}else{
urlurl = url + "?timestamp=" + timestamp;
}
return url;
}
function isrightcode(){
var code = $("#verycode").attr("value");
code = "c=" + code;
$.ajax({
type:"post",
url:"resultservlet/validatecode",
data:code,
success:callback
});
}
function callback(data){
$("#info").html(data);
}
</script>
运行效果：