去官方网站下载Jar包：
http://simplecaptcha.sourceforge.net/
Javadocs:
http://simplecaptcha.sourceforge.net/javadocs/index.html
自己书写工具类：
/*
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*/
package com.sino.gxh.util;
import java.awt.Color;
import java.awt.Font;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import nl.captcha.Captcha;
import nl.captcha.gimpy.FishEyeGimpyRenderer;
import nl.captcha.gimpy.RippleGimpyRenderer;
import nl.captcha.noise.CurvedLineNoiseProducer;
import nl.captcha.servlet.CaptchaServletUtil;
import nl.captcha.text.producer.DefaultTextProducer;
import nl.captcha.text.renderer.ColoredEdgesWordRenderer;
import nl.captcha.text.renderer.WordRenderer;
/**
*
* @author Administrator
*/
public class CodeMaker {
//验证码内容
private char[] numberChar = new char[]{'a', 'b', 'c', 'd',
'e', 'f', 'g', 'h', 'j', 'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
//验证码数量
private int _CodeCount = 4;
//验证码宽度
private int _width = 110;
//验证码高度
private int _height = 50;
//验证码颜色
private Color _CodeColor = Color.BLACK;
//使用字体名字
private String _FontName = "System";
//使用字体类型
private int _FontType = Font.BOLD;
//使用字体大小
private int _FontSize = 40;
//干扰线颜色
private Color _NoiseColor = Color.BLACK;
//干扰线大小
private int _NoiseSize = 2;
//干扰线条数
private int _NoiseCount = 1;
//验证图形码时是否开启大小写
private boolean whetherOpenBigOrSmall = false;
//验证码储存
private String CodeMemory;
//获取验证码
public void getCode(HttpServletResponse resp) {
Captcha.Builder captcha = new Captcha.Builder(_width, _height);
List<Font> fontList = new ArrayList<Font>();
List<Color> colorList = new ArrayList<Color>();
colorList.add(_CodeColor);
fontList.add(new Font(_FontName, _FontType, _FontSize));
WordRenderer dwr = new ColoredEdgesWordRenderer(colorList, fontList);
captcha.addText(new DefaultTextProducer(_CodeCount, numberChar), dwr);
for (int i = 0; i < _NoiseCount; i++) {
captcha.addNoise(new CurvedLineNoiseProducer(_NoiseColor, _NoiseSize));
}
captcha.gimp(new FishEyeGimpyRenderer(new Color(0, 0, 0, 0), new Color(0, 0, 0, 0)));
captcha.gimp(new RippleGimpyRenderer());
captcha.build();
Captcha captchas = captcha.build();
CaptchaServletUtil.writeImage(resp, captchas.getImage());
CodeMemory = captchas.getAnswer();
}
//比较验证码
public boolean compareCode(String Code) {
if (null == Code || "".equals(Code)) {
return false;
} else {
boolean bz;
System.out.println(whetherOpenBigOrSmall);
if (whetherOpenBigOrSmall) {
bz = CodeMemory.equals(Code);
} else {
bz = CodeMemory.equalsIgnoreCase(Code);
}
return bz;
}
}
public boolean isWhetherOpenBigOrSmall() {
return whetherOpenBigOrSmall;
}
public void setWhetherOpenBigOrSmall(boolean whetherOpenBigOrSmall) {
this.whetherOpenBigOrSmall = whetherOpenBigOrSmall;
}
public char[] getNumberChar() {
return numberChar;
}
public void setNumberChar(char[] numberChar) {
this.numberChar = numberChar;
}
public int getCodeCount() {
return _CodeCount;
}
public void setCodeCount(int _CodeCount) {
this._CodeCount = _CodeCount;
}
public int getWidth() {
return _width;
}
public void setWidth(int _width) {
this._width = _width;
}
public int getHeight() {
return _height;
}
public void setHeight(int _height) {
this._height = _height;
}
public Color getCodeColor() {
return _CodeColor;
}
public void setCodeColor(Color _CodeColor) {
this._CodeColor = _CodeColor;
}
public String getFontName() {
return _FontName;
}
public void setFontName(String _FontName) {
this._FontName = _FontName;
}
public int getFontType() {
return _FontType;
}
public void setFontType(int _FontType) {
this._FontType = _FontType;
}
public int getFontSize() {
return _FontSize;
}
public void setFontSize(int _FontSize) {
this._FontSize = _FontSize;
}
public Color getNoiseColor() {
return _NoiseColor;
}
public void setNoiseColor(Color _NoiseColor) {
this._NoiseColor = _NoiseColor;
}
public int getNoiseSize() {
return _NoiseSize;
}
public void setNoiseSize(int _NoiseSize) {
this._NoiseSize = _NoiseSize;
}
public int getNoiseCount() {
return _NoiseCount;
}
public void setNoiseCount(int _NoiseCount) {
this._NoiseCount = _NoiseCount;
}
}
调用和比较：
@RequestMapping(value = "/imagesanpeng", method = RequestMethod.GET)
protected void imagesanpeng(HttpServletRequest req, HttpServletResponse resp)
throws Exception {
CodeMaker c = new CodeMaker();
c.getCode(resp);
req.getSession().setAttribute("code", c);
}
@RequestMapping(value = "/txmbj", method = RequestMethod.POST)
protected void txmbj(HttpServletRequest req, HttpServletResponse resp,
@RequestParam(value = "txyzm", required = true) String txyzm)
throws Exception {
CodeMaker c = (CodeMaker) req.getSession().getAttribute("code");
c.setWhetherOpenBigOrSmall(true);
resp.getWriter().print(c.compareCode(txyzm));
resp.getWriter().flush();
resp.getWriter().close();
// CodeMaker c = new CodeMaker();
// c.setWhetherOpenBigOrSmall(true);
// resp.getWriter().print(c.compareCode(req, resp, txyzm));
// resp.getWriter().flush();
// resp.getWriter().close();
}