java实用验证码的实现代码

本文为大家分享了java实用验证码的实现代码，供大家参考，具体内容如下

1、validcode     

package validimg;
 
import java.awt.color;
import java.io.ioexception;
import java.util.random;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import javax.servlet.http.httpsession;
import com.github.bingoohuang.patchca.color.colorfactory;
import com.github.bingoohuang.patchca.custom.configurablecaptchaservice;
import com.github.bingoohuang.patchca.filter.predefined.curvesripplefilterfactory;
import com.github.bingoohuang.patchca.filter.predefined.diffuseripplefilterfactory;
import com.github.bingoohuang.patchca.filter.predefined.doubleripplefilterfactory;
import com.github.bingoohuang.patchca.filter.predefined.marbleripplefilterfactory;
import com.github.bingoohuang.patchca.filter.predefined.wobbleripplefilterfactory;
import com.github.bingoohuang.patchca.utils.encoder.encoderhelper;
import com.github.bingoohuang.patchca.word.randomwordfactory;
 
public class validcode extends httpservlet {
  private static configurablecaptchaservice cs = new configurablecaptchaservice();
  private static random random = new random();
  static {
//    cs.setcolorfactory(new singlecolorfactory(new color(25, 60, 170)));
  
    cs.setcolorfactory(new colorfactory() {
      @override
      public color getcolor(int x) {
        int[] c = new int[3];
        int i = random.nextint(c.length);
        for (int fi = 0; fi < c.length; fi++) {
          if (fi == i) {
            c[fi] = random.nextint(71);
          } else {
            c[fi] = random.nextint(256);
          }
        }
        return new color(c[0], c[1], c[2]);
      }
    });
    randomwordfactory wf = new randomwordfactory();
    wf.setcharacters("23456789abcdefghigkmnpqrstuvwxyzabcdefghigklmnpqrstuvwxyz");
    wf.setmaxlength(4);
    wf.setminlength(4);
    cs.setwordfactory(wf);
  }
 
 
  public void doget(httpservletrequest request, httpservletresponse response)
      throws servletexception, ioexception {
 
    switch (random.nextint(5)) {
    case 0:
      cs.setfilterfactory(new curvesripplefilterfactory(cs
          .getcolorfactory()));
      break;
    case 1:
      cs.setfilterfactory(new marbleripplefilterfactory());
      break;
    case 2:
      cs.setfilterfactory(new doubleripplefilterfactory());
      break;
    case 3:
      cs.setfilterfactory(new wobbleripplefilterfactory());
      break;
    case 4:
      cs.setfilterfactory(new diffuseripplefilterfactory());
      break;
    }
    httpsession session = request.getsession(false);
    if (session == null) {
      session = request.getsession();
    }
    setresponseheaders(response);
    string token = encoderhelper.getchallangeandwriteimage(cs, "png",
        response.getoutputstream());
    session.setattribute("validcode", token);
    system.out.println("当前的sessionid=" + session.getid() + "，验证码= ," + token);
 
  }
 
  protected void setresponseheaders(httpservletresponse response) {
    response.setcontenttype("image/png");
    response.setheader("cache-control", "no-cache, no-store");
    response.setheader("pragma", "no-cache");
    long time = system.currenttimemillis();
    response.setdateheader("last-modified", time);
    response.setdateheader("date", time);
    response.setdateheader("expires", time);
  }
 
  public void dopost(httpservletrequest request, httpservletresponse response)
      throws servletexception, ioexception {
 
  }
 
 
}

2.xml代码

<dependency>
  <groupid>com.github.bingoohuang</groupid>
  <artifactid>patchca</artifactid>
  <version>0.0.1</version>
 </dependency>
 
<servlet>
 <servlet-name>validcode</servlet-name>
 <servlet-class>validimg.validcode</servlet-class>
</servlet>
<servlet-mapping>
 <servlet-name>validcode</servlet-name>
 <url-pattern>/validimg.jpg</url-pattern>
</servlet-mapping>

以上就是本文的全部内容，希望对大家的学习有所帮助。