驗證碼 生成 及展示
/* *前段 */
<script>
function changeImage(){
var fullurl = '${ctx }/sync/data/getCode?version='+Math.random();
var image = document.getElementById("imageid");
image.src = fullurl;
}
</script>
//後端 package com.becom.modules.syncdata.web; import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import java.util.Random;
import javax.imageio.ImageIO;
/**
-
驗證碼生成器
-
轉載 https://www.cnblogs.com/yhtboke/p/5749126.html */ public class ValidateCode { // 圖片的寬度。 private int width = 160; // 圖片的高度。 private int height = 28; // 驗證碼字元個數 private int codeCount = 4; // 驗證碼干擾線數 private int lineCount = 150; // 驗證碼 private String code = null; // 驗證碼圖片Buffer private BufferedImage buffImg = null;
private char[] codeSequence = { ‘A’, ‘B’, ‘C’, ‘D’, ‘E’, ‘F’, ‘G’, ‘H’, ‘I’, ‘J’, ‘K’, ‘L’, ‘M’, ‘N’, ‘P’, ‘Q’, ‘R’, ‘S’, ‘T’, ‘U’, ‘V’, ‘W’, ‘X’, ‘Y’, ‘Z’, ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, ‘9’ };
public ValidateCode() { this.createCode(); }
/** *
- @param width
-
圖片寬
- @param height
-
圖片高
*/ public ValidateCode(int width, int height) { this.width = width; this.height = height; this.createCode(); }
/** *
- @param width
-
圖片寬
- @param height
-
圖片高
- @param codeCount
-
字元個數
- @param lineCount
-
干擾線條數
*/ public ValidateCode(int width, int height, int codeCount, int lineCount) { this.width = width; this.height = height; this.codeCount = codeCount; this.lineCount = lineCount; this.createCode(); }
public void createCode() { int x = 0, fontHeight = 0, codeY = 0; int red = 0, green = 0, blue = 0;
x = width / (codeCount + 2);// 每個字元的寬度 fontHeight = height - 2;// 字型的高度 codeY = height - 4; // 影象buffer buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = buffImg.createGraphics(); // 生成隨機數 Random random = new Random(); // 將影象填充為白色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); // 建立字型 Font font = new Font("Fixedsys", Font.BOLD, fontHeight); g.setFont(font); //干擾線 for (int i = 0; i < lineCount; i++) { int xs = random.nextInt(width); int ys = random.nextInt(height); int xe = xs + random.nextInt(width / 8); int ye = ys + random.nextInt(height / 8); red = random.nextInt(255); green = random.nextInt(255); blue = random.nextInt(255); g.setColor(new Color(red, green, blue)); g.drawLine(xs, ys, xe, ye); } // randomCode記錄隨機產生的驗證碼 StringBuffer randomCode = new StringBuffer(); // 隨機產生codeCount個字元的驗證碼。 for (int i = 0; i < codeCount; i++) { String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]); // 產生隨機的顏色值,讓輸出的每個字元的顏色值都將不同。 red = random.nextInt(255); green = random.nextInt(255); blue = random.nextInt(255); g.setColor(new Color(red, green, blue)); g.drawString(strRand, (i + 1) * x, codeY); // 將產生的四個隨機數組合在一起。 randomCode.append(strRand); } // 將四位數字的驗證碼儲存到Session中。 code = randomCode.toString();
}
public void write(String path) throws IOException { OutputStream sos = new FileOutputStream(path); this.write(sos); }
public void write(OutputStream sos) throws IOException { ImageIO.write(buffImg, “png”, sos); sos.close(); }
public BufferedImage getBuffImg() { return buffImg; }
public String getCode() { return code; } }
//控制層返回驗證碼流檔案 @RequestMapping("/getCode") public void getCode(HttpServletRequest reqeust, HttpServletResponse response) throws IOException {
response.setContentType("image/jpeg"); // 禁止影象快取。 response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); HttpSession session = reqeust.getSession(); ValidateCode vCode = new ValidateCode(100, 28, 4, 100); session.setAttribute(Helper.SESSION_CHECKCODE, vCode.getCode()); vCode.write(response.getOutputStream());
}