java相关：kaptcha验证码使用方法详解
发布于 -6-7|
复制链接
摘记: 本文为大家分享了kaptcha验证码的使用方法，供大家参考，具体内容如下1.首先在pom.xml文件中导入Maven依赖
```jfx
com.github.penggle
kaptcha
..
本文为大家分享了kaptcha验证码的使用方法，供大家参考，具体内容如下1.首先在pom.xml文件中导入Maven依赖
```jfx
com.github.penggle
kaptcha
2.3.2
```
2.在web.xml文件中配置一个servlet
```xml
Kaptcha
com.google.code.kaptcha.servlet.KaptchaServlet
kaptcha.border
no
kaptcha.textproducer.font.color
red
kaptcha.image.width
135
kaptcha.textproducer.char.string
ACDEFHKPRSTWX345679
kaptcha.image.height
50
kaptcha.textproducer.font.size
43
kaptcha.noise.color
black
kaptcha.textproducer.char.length
4
kaptcha.textproducer.font.names
Arial
Kaptcha
/Kaptcha
```
3.页面代码如下
```xhtml
验证码
```
向后端提交数据
```javascript
var verifyCodeActual = $('#j_captcha').val();
if (!verifyCodeActual) {
$.toast('请输入验证码！');
return;
}
formData.append("verifyCodeActual", verifyCodeActual);
```
4.js交互
```javascript
function changeVerifyCode(img) {
img.src = "../Kaptcha?" + Math.floor(Math.random() * 100);
}
```
5.后端验证
```java
import javax.servlet.http.HttpServletRequest;
public class CodeUtil {
public static boolean checkVerifyCode(HttpServletRequest request) {
String verifyCodeExpected = (String) request.getSession().getAttribute(
com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);
String verifyCodeActual = HttpServletRequestUtil.getString(request,
"verifyCodeActual");
if (verifyCodeActual == null
|| !verifyCodeActual.equalsIgnoreCase(verifyCodeExpected)) {
return false;
}
return true;
}
}
```
```java
import javax.servlet.http.HttpServletRequest;
public class HttpServletRequestUtil {
public static int getInt(HttpServletRequest request, String name) {
try {
return Integer.decode(request.getParameter(name));
} catch (Exception e) {
return -1;
}
}
public static long getLong(HttpServletRequest request, String name) {
try {
return Long.valueOf(request.getParameter(name));
} catch (Exception e) {
return -1;
}
}
public static Double getDouble(HttpServletRequest request, String name) {
try {
return Double.valueOf(request.getParameter(name));
} catch (Exception e) {
return -1d;
}
}
public static Boolean getBoolean(HttpServletRequest request, String name) {
try {
return Boolean.valueOf(request.getParameter(name));
} catch (Exception e) {
return false;
}
}
public static String getString(HttpServletRequest request, String name) {
try {
String result = request.getParameter(name);
if (result != null) {
result = result.trim();
}
if ("".equals(result))
result = null;
return result;
} catch (Exception e) {
return null;
}
}
}
```
