什麼是檢查captcha的條件

Question

我想檢查我的註冊表單中的驗證碼，它是從java文件中靜態生成的項目中。但是我無法追蹤檢查驗證碼的情況，它一直顯示錯誤。無論驗證碼是否匹配，它總是顯示無效的驗證碼。下面是代碼。

mainactivity.java

     Submit_btn.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      //isValidData(); 
      if (isValidData()){ 
       if (textCaptcha.checkAnswer(Usercapt.getText().toString().trim())) { 
        /*AlertDialog.Builder alt = new AlertDialog.Builder(MainActivity.this); 
        alt.setMessage("Invalid Captcha"); 
        alt.setCancelable(true); 
        alt.setPositiveButton("ok", new DialogInterface.OnClickListener() { 
         @Override 
         public void onClick(DialogInterface dialog, int which) { 
          dialog.dismiss(); 
         } 
        }); 
        AlertDialog alertDialog = alt.create(); 
        alertDialog.show();*/ 
        Toast.makeText(MainActivity.this, "captch match", Toast.LENGTH_SHORT).show(); 

       } else{ 
        /* Toast.makeText(MainActivity.this, "Successful Registration", Toast.LENGTH_SHORT).show(); 
        Intent i = new Intent(MainActivity.this, Login_Activity.class); 
        startActivity(i);*/ 
        Toast.makeText(MainActivity.this, "captcha not match", Toast.LENGTH_SHORT).show(); 

       } 
      } else { 

       /*here the code to save the data in data base will be written*/ 
       Toast.makeText(MainActivity.this, "Registration Failed, Register again", Toast.LENGTH_SHORT).show(); 

      } 

     } 
    }); 

Captcha.java

 package com.mws.tms_application; 

    import android.graphics.Bitmap; 
import android.graphics.Color; 

import java.util.List; 
import java.util.Random; 



public abstract class Captcha { 
protected Bitmap image; 
protected String answer = ""; 
private int width; 
protected int height; 
protected int x = 0; 
protected int y = 0; 
protected static List usedColors ; 

protected abstract Bitmap image(); 

public static int color(){ 
    Random r = new Random(); 
    int number; 
    do{ 
     number = r.nextInt(9); 
    }while(usedColors.contains(number)); 
    usedColors.add(number); 
    switch(number){ 
     case 0: return Color.BLACK; 
     case 1: return Color.BLUE; 
     case 2: return Color.CYAN; 
     case 3: return Color.DKGRAY; 
     case 4: return Color.GRAY; 
     case 5: return Color.GREEN; 
     case 6: return Color.MAGENTA; 
     case 7: return Color.RED; 
     case 8: return Color.YELLOW; 
     case 9: return Color.WHITE; 
     default: return Color.WHITE; 
    } 
} 

public int getWidth(){ 
    return this.width; 
} 

public void setWidth(int width){ 
    if(width > 0 && width < 10000){ 
     this.width = width; 
    }else{ 
     this.width = 300; 
    } 
} 

public int getHeight(){ 
    return this.height; 
} 

public void setHeight(int height){ 
    if(height > 0 && height < 10000){ 
     this.height = height; 
    }else{ 
     this.height = 100; 
    } 
} 

public Bitmap getImage() { 
    return this.image; 
} 

public boolean checkAnswer(String ans) { 
    /*System.out.println("ans received here"+ans); 
    System.out.println("captcha"+answer);*/ 
    return (ans.equals(this.answer)); 


} 
} 

textcaptcha.java

  package com.mws.tms_application; 

import android.graphics.Bitmap; 
import android.graphics.Canvas; 
import android.graphics.LinearGradient; 
import android.graphics.Paint; 
import android.graphics.Shader; 

import java.io.CharArrayWriter; 
import java.util.ArrayList; 
import java.util.Random; 



public class TextCaptcha extends Captcha { 

protected TextOptions options; 
private int wordLength; 
private char mCh; 

public enum TextOptions { 
    UPPERCASE_ONLY, 
    LOWERCASE_ONLY, 
    NUMBERS_ONLY, 
    LETTERS_ONLY, 
    NUMBERS_AND_LETTERS 
} 

public TextCaptcha(int wordLength, TextOptions opt) { 
    new TextCaptcha(0, 0, wordLength, opt); 
} 

public TextCaptcha(int width, int height, int wordLength, TextOptions opt) { 
    setHeight(height); 
    setWidth(width); 
    this.options = opt; 
    usedColors = new ArrayList<>(); 
    this.wordLength = wordLength; 
    this.image = image(); 
} 

@Override 
protected Bitmap image() { 
    LinearGradient gradient = new LinearGradient(0, 0, getWidth()/this.wordLength, getHeight()/2, color(), color(), Shader.TileMode.CLAMP); 
    Paint p = new Paint(); 
    p.setDither(true); 
    p.setShader(gradient); 
    Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888); 
    Canvas c = new Canvas(bitmap); 
    c.drawRect(0, 0, getWidth(), getHeight(), p); 
    Paint tp = new Paint(); 
    tp.setDither(true); 
    tp.setTextSize(getWidth()/getHeight() * 20); 

    Random r = new Random(System.currentTimeMillis()); 
    CharArrayWriter cab = new CharArrayWriter(); 
    this.answer = " "; 
    for (int i = 0; i < this.wordLength; i++) { 
     char ch = ' '; 
     switch (options) { 
      case UPPERCASE_ONLY: 
       ch = (char) (r.nextInt(91 - 65) + (65)); 
       break; 
      case LOWERCASE_ONLY: 
       ch = (char) (r.nextInt(123 - 97) + (97)); 
       break; 
      case NUMBERS_ONLY: 
       ch = (char) (r.nextInt(58 - 49) + (49)); 
       break; 
      case LETTERS_ONLY: 
       ch = getLetters(r); 
       break; 
      case NUMBERS_AND_LETTERS: 
       ch = getLettersNumbers(r); 
       break; 
      default: 
       ch = getLettersNumbers(r); 
       break; 
     } 
     cab.append(ch); 
     this.answer += ch; 
    } 

    char[] data = cab.toCharArray(); 
    for (int i = 0; i < data.length; i++) { 
     this.x += (30 - (3 * this.wordLength)) + (Math.abs(r.nextInt()) % (65 - (1.2 * this.wordLength))); 
     this.y = 50 + Math.abs(r.nextInt()) % 50; 
     Canvas cc = new Canvas(bitmap); 
     tp.setTextSkewX(r.nextFloat() - r.nextFloat()); 
     tp.setColor(color()); 
     cc.drawText(data, i, 1, this.x, this.y, tp); 
     tp.setTextSkewX(0); 
    } 
    return bitmap; 
} 

private char getLetters(Random r) { 
    int rint = (r.nextInt(123 - 65) + (65)); 
    if (((rint > 90) && (rint < 97))) 
     getLetters(r); 
    else 
     mCh = (char) rint; 
    return mCh; 
} 

private char getLettersNumbers(Random r) { 
    int rint = (r.nextInt(123 - 49) + (49)); 

    if (((rint > 90) && (rint < 97))) 
     getLettersNumbers(r); 
    else if (((rint > 57) && (rint < 65))) 
     getLettersNumbers(r); 
    else 
     mCh = (char) rint; 
    return mCh; 
} 
} 

Answer 1

就是這樣

初始化answer有水療CE，不是空字符串：

this.answer = " "; 

答案將填補這樣「1234567」通知前導空格。

要麼空字符串初始化：

this.answer = ""; 

或者比較

上 answer使用 trim()

public boolean checkAnswer(String ans) { 
    /*System.out.println("ans received here"+ans); 
    System.out.println("captcha"+answer);*/ 
    return (ans.equals(this.answer.trim())); 
} 

推薦的方法是使用空字符串初始化answer