IntelliJ IDEA实现网页生成验证码相关模块:
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
public final class ImageUtil {
private static final char[] chars = { '0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I' };
private static final int SIZE = 4;
private static final int LINES = 5;
private static final int WIDTH = 80;
private static final int HEIGHT = 40;
private static final int FONT_SIZE = 30;
public static Map<String, BufferedImage> createImage() {
StringBuffer sb = new StringBuffer();
BufferedImage image = new BufferedImage(WIDTH, HEIGHT,
BufferedImage.TYPE_INT_RGB);
Graphics graphic = image.getGraphics();
graphic.setColor(Color.LIGHT_GRAY);
graphic.fillRect(0, 0, WIDTH, HEIGHT);
Random ran = new Random();
for (int i = 1; i <= SIZE; i++) {
int r = ran.nextInt(chars.length);
graphic.setColor(getRandomColor());
graphic.setFont(new Font(null, Font.BOLD + Font.ITALIC, FONT_SIZE));
graphic.drawString(chars[r] + "", (i - 1) * WIDTH / SIZE,
HEIGHT / 2);
sb.append(chars[r]);
}
for (int i = 1; i <= LINES; i++) {
graphic.setColor(getRandomColor());
graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT),
ran.nextInt(WIDTH), ran.nextInt(HEIGHT));
}
Map<String, BufferedImage> map = new HashMap<String, BufferedImage>();
map.put(sb.toString(), image);
return map;
}
public static Color getRandomColor() {
Random ran = new Random();
Color color = new Color(ran.nextInt(256), ran.nextInt(256),
ran.nextInt(256));
return color;
}
public static InputStream getInputStream(BufferedImage image)
throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos);
encoder.encode(image);
byte[] imageBts = bos.toByteArray();
InputStream in = new ByteArrayInputStream(imageBts);
return in;
}
}
生成验证码ImageUtill类
/**
* 产生登录页面验证码
*/
@RequestMapping("/createImage.do")
public void createImage(
HttpServletResponse response, HttpSession session)
throws Exception {
Map<String, BufferedImage> imageMap = ImageUtil.createImage();
String code = imageMap.keySet().iterator().next();
session.setAttribute("imageCode", code);
BufferedImage image = imageMap.get(code);
response.setContentType("image/jpeg");
OutputStream ops = response.getOutputStream();
ImageIO.write(image, "jpeg", ops);
ops.close();
}
JSP网页调用(片段,将上面的ceateImage.do放入src中):
<tr>
<td class="login_info">验证码:</td>
<td class="width70"><input name="code" type="text" class="width70" id="code" onfocus="set_msg('code_msg','');"/></td>
<td><img src="createImage.do" alt="验证码" title="点击更换" id="code_image" onclick="change();"/></td>
<td><span class="required" id="code_msg"></span></td>
</tr>
程序确定是无误的!
可以写成Java程序进行验证图片的生成:
package sample;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
primaryStage.setTitle("Hello World");
String code = ImageUtil.outputtofile();
Image image = new Image("ttt.jpeg");
Label label = new Label(code);
ImageView imageView = new ImageView(image);
HBox hBox =new HBox();
Scene scene = new Scene(hBox, 300, 275);
hBox.getChildren().addAll(imageView,label);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
class ImageUtil {
private static final char[] chars = { '0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I' };
private static final int SIZE = 4;
private static final int LINES = 5;
private static final int WIDTH = 80;
private static final int HEIGHT = 40;
private static final int FONT_SIZE = 30;
public static Map<String, BufferedImage> createImage() {
StringBuffer sb = new StringBuffer();
BufferedImage image = new BufferedImage(WIDTH, HEIGHT,
BufferedImage.TYPE_INT_RGB);
Graphics graphic = image.getGraphics();
graphic.setColor(Color.LIGHT_GRAY);
graphic.fillRect(0, 0, WIDTH, HEIGHT);
Random ran = new Random();
for (int i = 1; i <= SIZE; i++) {
int r = ran.nextInt(chars.length);
graphic.setColor(getRandomColor());
graphic.setFont(new Font(null, Font.BOLD + Font.ITALIC, FONT_SIZE));
graphic.drawString(chars[r] + "", (i - 1) * WIDTH / SIZE,
HEIGHT / 2);
sb.append(chars[r]);
}
for (int i = 1; i <= LINES; i++) {
graphic.setColor(getRandomColor());
graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT),
ran.nextInt(WIDTH), ran.nextInt(HEIGHT));
}
Map<String, BufferedImage> map = new HashMap<String, BufferedImage>();
map.put(sb.toString(), image);
return map;
}
public static Color getRandomColor() {
Random ran = new Random();
Color color = new Color(ran.nextInt(256), ran.nextInt(256),
ran.nextInt(256));
return color;
}
public static InputStream getInputStream(BufferedImage image)
throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos);
encoder.encode(image);
byte[] imageBts = bos.toByteArray();
InputStream in = new ByteArrayInputStream(imageBts);
return in;
}
public static String outputtofile() {
Map<String,String> map = new HashMap<>() ;
Map<String, BufferedImage> imageMap = createImage();
String code = imageMap.keySet().iterator().next();
BufferedImage image = imageMap.get(code);
try {
OutputStream ops = new FileOutputStream("src/ttt.jpeg");
ImageIO.write(image, "jpeg", ops);
ops.flush();
}catch (FileNotFoundException ex){
}catch (IOException ex) {
}
return code;
}
}
javaFx显示图片
上述代码有个问题:每次显示的图片都是上一次的,但文件中保存的图片是正确的。目前该问题不知如何解决?
但是:在网页中无法显示验证码图片。错误信息是无法写入Tomcat的temp目录,但temp目录肯定是存在的,原因是写入temp目录必须要管理员权限。
解决方法:
进入tomcat安装目录:C:\Program Files\Apache Software Foundation\Tomcat 8.5
右击temp属性:
对所有用户勾选所有权限,问题解决!!!