Android Captcha 防止機器人 生成隨機驗證碼，這個隨機驗證碼可以輕易的擋掉那些機器人來做一些事情，此方法是使用09和AZ的所有組合，她可以有效的防止機器人攻擊你的伺服器，隨機驗證碼是你的好幫手來阻止伺服器被機器人攻破。
package com.example.test
import android.graphics.*
import java.lang.StringBuilder
import java.util.*
/**
* Author: Wade
* E-mail: tony91097@gmail.com
* Date: 2021/9/22
*/
class Captcha private constructor() {
companion object {
val CHARS_NUMBER = arrayListOf('0', '1', '2', '3', '4', '5', '6', '7', '8', '9')
val CHARS_LETTER = arrayListOf(
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
'X', 'Y', 'Z'
)
val CHARS_ALL = arrayListOf(
'0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
'X', 'Y', 'Z'
)
val instance: Captcha by lazy(LazyThreadSafetyMode.SYNCHRONIZED) { Captcha() }
}
/**
* 驗證碼寬度
*/
private var mWidth = 0
/**
* 驗證碼高度
*/
private var mHeight = 0
/**
* 驗證碼背景顏色
*/
private var mBackgroundColor = 0
/**
* 驗證碼長度
*/
private var mLength = 0
/**
* 干擾線的數量
*/
private var mLineNumber = 0
/**
* 驗證碼文字大小
*/
private var mFontSize = 0
/**
* 字體左邊距
*/
private var mFontPaddingLeft = 0
/**
* 字體左邊距範圍值
*/
private var mFontPaddingLeftRange = 0
/**
* 字體上邊距
*/
private var mFontPaddingTop = 0
/**
* 字體上邊距範圍值
*/
private var mFontPaddingTopRange = 0
/**
* 圖片倍率
*/
private var mScale = 0
private var mType: TYPE
private var mRandom: Random
private lateinit var mCode: String
sealed class TYPE {
object NUMBER : TYPE()
object LETTER : TYPE()
object CHARS : TYPE()
}
init {
mType = TYPE.CHARS
mScale = 1
mWidth = 200
mHeight = 100
mBackgroundColor = Color.WHITE
mLength = 4
mLineNumber = 5
mFontSize = 50
mFontPaddingLeft = 25
mFontPaddingLeftRange = 20
mFontPaddingTop = 60
mFontPaddingTopRange = 20
mRandom = Random()
}
fun setType(type: TYPE): Captcha {
mType = type
return instance
}
fun setScale(scale: Int): Captcha {
mScale = scale
return instance
}
fun setSize(width: Int, height: Int): Captcha {
mWidth = width * mScale
mHeight = height * mScale
return instance
}
fun setBackgroundColor(color: Int): Captcha {
mBackgroundColor = color
return instance
}
fun setLength(length: Int): Captcha {
mLength = length
return instance
}
fun setLineNumber(number: Int): Captcha {
mLineNumber = number
return instance
}
fun setFontSize(size: Int): Captcha {
mFontSize = size * mScale
return instance
}
fun setFontPadding(paddingLeft: Int, paddingTop: Int): Captcha {
mFontPaddingLeft = paddingLeft * mScale
mFontPaddingTop = paddingTop * mScale
return instance
}
fun setFontPadding(
paddingLeft: Int,
paddingLeftRange: Int,
paddingTop: Int,
paddingRange: Int
): Captcha {
mFontPaddingLeft = paddingLeft * mScale
mFontPaddingLeftRange = paddingLeftRange * mScale
mFontPaddingTop = paddingTop * mScale
mFontPaddingTopRange = paddingRange * mScale
return instance
}
/**
* 獲取驗證碼
*/
fun getCode() = mCode
fun create(): Bitmap {
mCode = createCode()
val bitmap = Bitmap.createBitmap(mWidth, mHeight, Bitmap.Config.ARGB_8888)
val canvas = Canvas(bitmap)
canvas.drawColor(mBackgroundColor)
val paint = Paint(Paint.ANTI_ALIAS_FLAG)
paint.textSize = mFontSize.toFloat()
var fontPaddingLeft = 0
for (code in mCode) {
getRandomTextStyle(paint)
fontPaddingLeft += getRandomFontPaddingLeft()
canvas.drawText(
code.toString(),
fontPaddingLeft.toFloat(),
getRandomFontPaddingTop().toFloat(),
paint
)
}
for (i in 0 until mLineNumber) {
drawLine(canvas, paint)
}
canvas.save()
canvas.restore()
return bitmap
}
private fun drawLine(canvas: Canvas, paint: Paint) {
val color = getRandomColor()
val startX = mRandom.nextInt(mWidth)
val startY = mRandom.nextInt(mHeight)
val stopX = mRandom.nextInt(mWidth)
val stopY = mRandom.nextInt(mHeight)
paint.strokeWidth = 1f
paint.color = color
canvas.drawLine(startX.toFloat(), startY.toFloat(), stopX.toFloat(), stopY.toFloat(), paint)
}
private fun getRandomFontPaddingLeft() =
mFontPaddingLeft + mRandom.nextInt(mFontPaddingLeftRange)
private fun getRandomFontPaddingTop() = mFontPaddingTop + mRandom.nextInt(mFontPaddingTopRange)
private fun getRandomTextStyle(paint: Paint) {
val color = getRandomColor()
paint.color = color
paint.isFakeBoldText = mRandom.nextBoolean()
var skewX = mRandom.nextInt(11) / 10
skewX = if (mRandom.nextBoolean()) skewX else -skewX
paint.textSkewX = skewX.toFloat()
}
private fun getRandomColor(): Int {
val red = mRandom.nextInt(256)
val green = mRandom.nextInt(256)
val blue = mRandom.nextInt(256)
return Color.rgb(red, green, blue)
}
private fun createCode(): String {
val buffer = StringBuilder()
when (mType) {
TYPE.NUMBER -> {
for (i in 0 until mLength) {
buffer.append(CHARS_NUMBER[mRandom.nextInt(CHARS_NUMBER.size)])
}
}
TYPE.LETTER -> {
for (i in 0 until mLength) {
buffer.append(CHARS_LETTER[mRandom.nextInt(CHARS_LETTER.size)])
}
}
TYPE.CHARS -> {
for (i in 0 until mLength) {
buffer.append(CHARS_ALL[mRandom.nextInt(CHARS_ALL.size)])
}
}
}
return buffer.toString()
}
}<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.appcompat.widget.AppCompatImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
app:layout_constraintStart_toStartOf="@+id/code"
app:layout_constraintTop_toBottomOf="@+id/code"
tools:srcCompat="@tools:sample/avatars" />
<androidx.appcompat.widget.AppCompatEditText
android:hint="請輸入驗證碼"
android:maxLength="4"
android:id="@+id/code"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="36dp"
android:ems="10"
android:inputType="textPersonName"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.appcompat.widget.AppCompatButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="驗證"
android:onClick="validate"
app:layout_constraintBottom_toBottomOf="@+id/code"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/code"
app:layout_constraintTop_toTopOf="@+id/code" />
<androidx.appcompat.widget.AppCompatTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:text="看不清楚可點擊圖片更換"
android:textColor="@color/black"
android:textSize="16sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/imageView"
app:layout_constraintTop_toTopOf="@+id/imageView" />
</androidx.constraintlayout.widget.ConstraintLayout>val mCaptcha = Captcha.instance
.setType(Captcha.TYPE.CHARS)
.setScale(2)
.setSize(200, 100)
.setBackgroundColor(Color.WHITE)
.setLength(4)
.setLineNumber(5)
.setFontSize(50)
.setFontPadding(25, 20, 60, 20)package com.example.test
import android.graphics.Color
import android.os.Bundle
import android.view.View
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.appcompat.widget.AppCompatEditText
import androidx.appcompat.widget.AppCompatImageView
class MainActivity : AppCompatActivity() {
private lateinit var captcha: AppCompatImageView
private lateinit var code: AppCompatEditText
private lateinit var mCaptcha: Captcha
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
captcha = findViewById(R.id.imageView)
code = findViewById(R.id.code)
createCaptcha()
}
private fun createCaptcha() {
mCaptcha = Captcha.instance
.setType(Captcha.TYPE.CHARS)
.setScale(2)
.setSize(200, 100)
.setBackgroundColor(Color.WHITE)
.setLength(4)
.setLineNumber(5)
.setFontSize(50)
.setFontPadding(25, 20, 60, 20)
captcha.setImageBitmap(mCaptcha.create())
captcha.setOnClickListener {
captcha.setImageBitmap(mCaptcha.create())
}
}
fun validate(view: View) {
if (mCaptcha.getCode().equals(code.text.toString(), true)) {
Toast.makeText(this, "驗證成功", Toast.LENGTH_SHORT).show()
} else {
Toast.makeText(this, "驗證失敗", Toast.LENGTH_SHORT).show()
}
}
}