前言：认证在互联网中会经常见到，其主要作用是安全问题中防止恶意破解、刷票等。在系统开发中认证的实现也有很多种，什么手机短信认证，邮箱认证等。在这里我使用最基本的验证码的形式进行认证，下面例出过程。
验证码工具类（用来生成验证码）
创建一个简单的验证码生成器，通过流的方式将随机字体、随机背景色、干扰线、随机字符串，夹杂在一起形成验证码图片
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
/**
* 自定义验证码类
*/
public class VerifyCode {
private int width = 100; //生成验证码图片的宽度
private int height = 40; //生成验证码图片的高度
private String[] fontNames = {"宋体","楷体","隶书","微软雅黑"};
private Color bgColor = new Color(255,255,255); //定义验证码图片的背景色
private Random random = new Random();
private String codes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
private String text; //记录随机字符串
/**
* 获取随机一个颜色
* @return
*/
private Color randomColor(){
int red = random.nextInt(150);
int green = random.nextInt(150);
int blue = random.nextInt(150);
return new Color(red,green,blue);
}
/**
* 获取随机一个字体
* @return
*/
private Font randomFont(){
String name = fontNames[random.nextInt(fontNames.length)];
int style = random.nextInt(4);
int size =random.nextInt(5)+24;
return new Font(name,style,size);
}
/**
* 获取随机一个字符
* @return
*/
private char randomChar(){
return codes.charAt(random.nextInt(codes.length()));
}
/**
* 创建一个空白的BufferedImage对象
* @return
*/
private BufferedImage createImage(){
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = (Graphics2D)image.getGraphics();
g2.setColor(bgColor);
g2.fillRect(0,0,width,height);
return image;
}
/**
* 绘制干扰线
*/
private void drawLine(BufferedImage image){
Graphics2D g2 = (Graphics2D) image.getGraphics();
int num = 5;
for (int i = 0 ;i < num ; i++){
int x1 = random.nextInt(width);
int y1 = random.nextInt(height);
int x2 = random.nextInt(width);
int y2 = random.nextInt(height);
g2.setColor(randomColor());
g2.setStroke(new BasicStroke(1.5f));
g2.drawLine(x1, y1, x2, y2);
}
}
/**
* 绘制验证码
* @return
*/
public BufferedImage getImage(){
BufferedImage image = createImage();
Graphics2D g2 = (Graphics2D) image.getGraphics();
StringBuffer sb = new StringBuffer();
for (int i = 0 ; i < 4 ; i++){
String s = randomChar() + "";
sb.append(s);
g2.setColor(randomColor());
g2.setFont(randomFont());
float x = i * width * 1.0f / 4;
g2.drawString(s,x,height - 15);
}
this.text = sb.toString();
drawLine(image);
return image;
}
public String getText(){
return text;
}
/**
* 用流传输方法
* @return
*/
public static void output(BufferedImage image, OutputStream out) throws IOException {
ImageIO.write(image,"JPEG",out);
}
}controller层调用
创建VerifyCode验证码生成器实例，将text（随机字符串）存入session中，将图片用流的方式传入前段
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.image.BufferedImage;
import java.io.IOException;
@RestController
public class VerifyCodeController {
@GetMapping("/vercode")
public void code(HttpServletRequest req, HttpServletResponse resp) throws IOException {
//创建验证码生成器实例取得生成图片和随机字符串
VerifyCode vc = new VerifyCode();
BufferedImage image = vc.getImage();
String text = vc.getText();
//随机字符串存入session中
HttpSession session = req.getSession();
session.setAttribute("index_code",text);
//用流传输
VerifyCode.output(image,resp.getOutputStream());
}
}前段
前段我这里使用的是vue框架（使用什么框架不是问题，姑且提一下），img图片中src路劲调用
<img src="/vercode" alt="">启动服务器，测试，获取成功
前段-输入
我这里做登录认证，表单加入验证码输入
<tr>
<td>
<el-tag>验证码</el-tag>
</td>
<td>
<el-input size="mini" v-model="user.code" pleceholder="请输入验证码"></el-input>
</td>
<td>
<img src="/vercode" alt="">
</td>
</tr>
使用spring security做后台的验证
这里只提取验证码相关的：
过滤器
自定义过滤器，继承GenericFilterBean，重写doFilter方法
@Component
public class VerifyCodeFilter extends GenericFilterBean {
//绑定登录路径
private String defaultFilterProcessUrl = "/doLogin";
@Override
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) resp;
if ("POST".equalsIgnoreCase(request. getMethod()) && defaultFilterProcessUrl.equals(request.getServletPath())){
String requestCaptcha = request.getParameter("code");
String genCaptcha = (String) request.getSession().getAttribute("index_code");
if(StringUtils.isEmpty(requestCaptcha)){
throw new AuthenticationServiceException("验证码不能为空！");
}
if (!genCaptcha.toLowerCase().equals(requestCaptcha.toLowerCase())){
throw new AuthenticationServiceException("验证码错误！");
}
}
chain.doFilter(request,response);
}
}安全配置器
继承WebSecurityConfigurerAdapter类，重写认证方法
@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {
@Autowired
VerifyCodeFilter verifyCodeFilter;
@Override
public void configure(WebSecurity web) throws Exception {
//防止验证图片被拦截
web.ignoring().antMatchers("/vercode");
}
@Override
protected void configure(HttpSecurity http) throws Exception {
//对前段获取到的验证数据进行验证
http.addFilterBefore(verifyCodeFilter,UsernamePasswordAuthenticationFilter.class);
http.authorizeRequests()
//省略账号密码认证
...
...
...
.permitAll()
.and()
.csrf().disable()
}
}登录测试
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这次就到这里，有什么问题或建议可以在下面评论。