生成验证码的Servlet：Validatio
Codejava
packagezhuserlogi
sample
importjavaximageioImageIOimportjavaxservletServletExceptio
importjavaxservlethttpHttpServletimportjavaxservlethttpHttpServletRequestimportjavaxservlethttpHttpServletRespo
seimportjavaxservlethttpHttpSessio
importjavaawtimportjavaawtimageBufferedImageimportjavaioIOExceptio

fimportjavaioOutputStreamimportjavautilRa
dom
Createdbyzha
go
2014913
publicclassValidatio
Codeexte
dsHttpServletOverrideprotectedvoiddoGetHttpServletRequestreqHttpServletRespo
serespthrows
ServletExceptio
IOExceptio
获得验证码集合的长度i
tcharsLe
gthcodeCharsle
gth下面3条记录是关闭客户端浏览器的缓冲区这3条语句都可以关闭浏览器的缓冲区，但是由于浏览器的版本不同，对这3条
语句的支持也不同因此，为了保险起见，同时使用这3条语句来关闭浏览器的缓冲区respsetHeader