How to save the login verification code to redis by Java
This article mainly introduces "Java how to save login CAPTCHA to redis". In daily operation, I believe that many people have doubts about how to save login CAPTCHA to redis in Java. Xiaobian consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful to answer the question of "how to save login CAPTCHA to redis". Next, please follow the editor to study!
Introduce redis dependency
Org.springframework.boot
Spring-boot-starter-data-redis
CAPTCHA generation class
Package com.yishang.yspay.util
Import org.springframework.beans.factory.annotation.Autowired
Import org.springframework.data.redis.core.RedisTemplate
Import java.awt.*
Import java.util.Random
/ * *
* CAPTCHA generation class
, /
Public class RandomValidateCode {
Public static final String RANDOMCODEKEY = "RANDOMVALIDATECODEKEY"; / / key in session
/ / private String randString = "0123456789"; / / randomly generate the string private String with only numbers
/ / private String randString = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; / / randomly generate a string with only letters
Private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; / / randomly generates a string of numbers and letters
Private int width = 95 position / picture width
Private int height = 25umbnail / picture high
Private int lineSize = 10 / number of interference lines
Private int stringNum = 4 characters / number of characters randomly generated
/ * *
* redis tool
, /
@ Autowired
Private RedisTemplate redisTemplate
Private Random random = new Random ()
/ *
* get the font
, /
Private Font getFont () {
Return new Font ("Fixedsys", Font.CENTER_BASELINE, 24)
}
/ *
* get the color
, /
Public Color getRandColor (int fc, int bc) {
If (fc > 255)
Fc = 255,
If (bc > 255)
Bc = 255,
Int r = fc + random.nextInt (bc-fc-16)
Int g = fc + random.nextInt (bc-fc-14)
Int b = fc + random.nextInt (bc-fc-18)
Return new Color (r, g, b)
}
/ *
* draw string
, /
Public String drowString (Graphics g, String randomString, int I) {
G.setFont (getFont ())
G.setColor (new Color (random.nextInt, random.nextInt), random
.nextInt (121)
String rand = String.valueOf (getRandomString (random.nextInt (randString)
.length ()
RandomString + = rand
G.translate (random.nextInt (3), random.nextInt (3))
G.drawString (rand, 13 * I, 16)
Return randomString
}
/ *
* draw interference lines
, /
Public void drowLine (Graphics g) {
Int x = random.nextInt (width)
Int y = random.nextInt (height)
Int xl = random.nextInt (13)
Int yl = random.nextInt (15)
G.drawLine (x, y, x + xl, y + yl)
}
/ *
* get random characters
, /
Public String getRandomString (int num) {
Return String.valueOf (randString.charAt (num))
}
}
Interface
@ RequestMapping (value = "/ getVerify")
Public void getVerify (HttpServletRequest request, HttpServletResponse response) {
Response.setContentType ("image/jpeg"); / / set the corresponding type and tell the browser that the output is an image.
Response.setHeader ("Pragma", "No-cache"); / / set the response header information, telling the browser not to cache this content
Response.setHeader ("Cache-Control", "no-cache")
Response.setDateHeader ("Expire", 0)
RandomValidateCode randomValidateCode = new RandomValidateCode ()
/ / the BufferedImage class is an Image class with a buffer, and the Image class is a class used to describe image information.
BufferedImage image = new BufferedImage (95,25, BufferedImage.TYPE_INT_BGR)
Graphics g = image.getGraphics (); / / generate the Graphics object of the Image object, which can perform various drawing operations on the image
G.fillRect (0,0,95,25)
G.setFont (new Font ("Times New Roman", Font.ROMAN_BASELINE, 18))
G.setColor (randomValidateCode.getRandColor 110,133)
/ / draw interference lines
For (int I = 0; I
