一：自定义验证码
//AWT(Abstract Window Toolkit)抽象窗口工具包，Java的图形用户界面的基本工具
①：生成验证码BufferedImage.TYPE_INT_RGB
public class IcodeUtil {
/**
* 验证码中的内容
* @return
*/
public static char[] getRandomChars(){
char [] chs="0123456789abcdefghijklmnABCDEFGHIJKLMN".toCharArray();
char []vcode=new char [4];
Random random=new Random();
for(int i=0;i<4;i++){
vcode[i]=chs[random.nextInt(38)];
}
return vcode;
}
/**
* 将字符串绘制成图片 创建画布->用画布创建画笔->设置背景色和图形
* ->前景色和验证码->生成图片->返回画布对象。
* @param iCode
* @return
*/
public static BufferedImage getImage(char[] iCode){
//准备画图缓冲区
BufferedImage buffer=new BufferedImage(90,40,BufferedImage.TYPE_INT_BGR);
//创建画笔
Graphics g=buffer.getGraphics();
//背景色 ->绘制矩形
g.setColor(Color.BLACK);
g.drawRect(0, 0, 90, 40);
//前景色
g.setColor(Color.WHITE);
g.drawString(iCode[0]+"", 10, 25);
g.drawString(iCode[1]+"", 30, 25);
g.drawString(iCode[2]+"", 50, 25);
g.drawString(iCode[3]+"", 70, 25);
//生成图片
g.dispose();
return buffer;
}
}
②创建获得图片的Servlet
public class CodeJsp extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
char[] vCode=IcodeUtil.getRandomChars();
BufferedImage buffer=IcodeUtil.getImage(vCode);
ImageIO.write(buffer, "png", response.getOutputStream());
}
}
③指向页面中<img src=’servlet名’ />
out.write("<img src='code' />");
二：开源验证码
①导入源文件
public class CreateValidateCode {
// 图片的宽度。
private int width = 160;
// 图片的高度。
private int height = 40;
// 验证码字符个数
private int codeCount = 4;
// 验证码干扰线数
private int lineCount = 20;
// 验证码
private String code = null;
// 验证码图片Buffer
private BufferedImage buffImg = null;
Random random = new Random();
public CreateValidateCode() {
creatImage();
}
public CreateValidateCode(int width, int height) {
this.width = width;
this.height = height;
creatImage();
}
public CreateValidateCode(int width, int height, int codeCount) {
this.width = width;
this.height = height;
this.codeCount = codeCount;
creatImage();
}
public CreateValidateCode(int width, int height, int codeCount, int lineCount) {
this.width = width;
this.height = height;
this.codeCount = codeCount;
this.lineCount = lineCount;
creatImage();
}
// 生成图片
private void creatImage() {
int fontWidth = width / codeCount;// 字体的宽度
int fontHeight = height - 5;// 字体的高度
int codeY = height - 8;
// 图像buffer
buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = buffImg.getGraphics();
// Graphics2D g = buffImg.createGraphics();
// 设置背景色
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
// 设置字体
// Font font1 = getFont(fontHeight);
Font font = new Font("Fixedsys", Font.BOLD, fontHeight);
g.setFont(font);
// 设置干扰线
for (int i = 0; i < lineCount; i++) {
int xs = random.nextInt(width);
int ys = random.nextInt(height);
int xe = xs + random.nextInt(width);
int ye = ys + random.nextInt(height);
g.setColor(getRandColor(1, 255));
g.drawLine(xs, ys, xe, ye);
}
// 添加噪点
float yawpRate = 0.01f;// 噪声率
int area = (int) (yawpRate * width * height);
for (int i = 0; i < area; i++) {
int x = random.nextInt(width);
int y = random.nextInt(height);
buffImg.setRGB(x, y, random.nextInt(255));
}
String str1 = randomStr(codeCount);// 得到随机字符
this.code = str1;
for (int i = 0; i < codeCount; i++) {
String strRand = str1.substring(i, i + 1);
g.setColor(getRandColor(1, 255));
// g.drawString(a,x,y);
// a为要画出来的东西，x和y表示要画的东西最左侧字符的基线位于此图形上下文坐标系的 (x, y) 位置处
g.drawString(strRand, i * fontWidth + 3, codeY);
}
}
// 得到随机字符
private String randomStr(int n) {
String str1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
String str2 = "";
int len = str1.length() - 1;
double r;
for (int i = 0; i < n; i++) {
r = (Math.random()) * len;
str2 = str2 + str1.charAt((int) r);
}
return str2;
}
// 得到随机颜色
private Color getRandColor(int fc, int bc) {// 给定范围获得随机颜色
if (fc > 255)
fc = 255;
if (bc > 255)
bc = 255;
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}
/**
* 产生随机字体
*/
private Font getFont(int size) {
Random random = new Random();
Font font[] = new Font[5];
font[0] = new Font("Ravie", Font.PLAIN, size);
font[1] = new Font("Antique Olive Compact", Font.PLAIN, size);
font[2] = new Font("Fixedsys", Font.PLAIN, size);
font[3] = new Font("Wide Latin", Font.PLAIN, size);
font[4] = new Font("Gill Sans Ultra Bold", Font.PLAIN, size);
return font[random.nextInt(5)];
}
// 扭曲方法
private void shear(Graphics g, int w1, int h1, Color color) {
shearX(g, w1, h1, color);
shearY(g, w1, h1, color);
}
private void shearX(Graphics g, int w1, int h1, Color color) {
int period = random.nextInt(2);
boolean borderGap = true;
int frames = 1;
int phase = random.nextInt(2);
for (int i = 0; i < h1; i++) {
double d = (double) (period >> 1)
* Math.sin((double) i / (double) period
+ (6.2831853071795862D * (double) phase)
/ (double) frames);
g.copyArea(0, i, w1, 1, (int) d, 0);
if (borderGap) {
g.setColor(color);
g.drawLine((int) d, i, 0, i);
g.drawLine((int) d + w1, i, w1, i);
}
}
}
private void shearY(Graphics g, int w1, int h1, Color color) {
int period = random.nextInt(40) + 10; // 50;
boolean borderGap = true;
int frames = 20;
int phase = 7;
for (int i = 0; i < w1; i++) {
double d = (double) (period >> 1)
* Math.sin((double) i / (double) period
+ (6.2831853071795862D * (double) phase)
/ (double) frames);
g.copyArea(i, 0, 1, h1, 0, (int) d);
if (borderGap) {
g.setColor(color);
g.drawLine(i, (int) d, i, 0);
g.drawLine(i, (int) d + h1, i, h1);
}
}
}
public void write(OutputStream sos) throws IOException {
ImageIO.write(buffImg, "png", sos);
sos.close();
}
public BufferedImage getBuffImg() {
return buffImg;
}
public String getCode() {
return code.toLowerCase();
}
}
②创建Servlet完成图片的创建
// 使用方法（在Servlet中添加下面代码）
CreateValidateCode vCode = new CreateValidateCode(100, 30, 5, 10);
session.setAttribute("code", vCode.getCode()); //保存在Session作用域
vCode.write(response.getOutputStream());