使用java生成字母验证码

本文实例为大家分享了java生成字母验证码的具体代码，供大家参考，具体内容如下

import java.awt.basicstroke;
import java.awt.color;
import java.awt.font;
import java.awt.graphics2d;
import java.awt.image.bufferedimage;
import java.io.ioexception;
import java.io.outputstream;
import java.util.random;

import javax.imageio.imageio;


public class verifycode {
  //图片宽高
  private int w=70;
  private int h=35;
  private random r=new random();
  private string[] fontnames={"宋体","华文楷体","黑体","微软雅黑","楷体_gb2312"};
  private string codes="234567890qwertyuipasdfghjkzxcvbnmqwertyuipasdfghjkzxcvbnm";
  private color bgcolor=new color(255,255,255);
  private string text;
  //生成随机颜色
  private color randomcolor(){
    int red=r.nextint(150);
    int green=r.nextint(150);
    int blue=r.nextint(150);
    return new color(red, green, blue);
    }
  //生成随机字体
  private font randomfont(){
    int index=r.nextint(fontnames.length);
    string fontname=fontnames[index];
    int style=r.nextint(4);//0 无 1 粗体 2 斜体 3 粗+斜
    int size=r.nextint(5)+24; //生成随机字号 24~28
    return new font(fontname, style, size);
  }
  //干扰线
  private void drowline(bufferedimage image){
    //生成4条干扰线
    int num=4;
    graphics2d bi=(graphics2d) image.getgraphics();
    for (int i = 0; i < num; i++) {
      int x1=r.nextint(w);
      int x2=r.nextint(w);
      int y1=r.nextint(h);
      int y2=r.nextint(h);
      bi.setstroke(new basicstroke(1.5f));
      bi.setcolor(color.blue);//干扰线色
      bi.drawline(x1,y1,x2,y2);
    }
  }
  //随机生成一个字符
  private char randomchar(){
    int index=r.nextint(codes.length());
    return codes.charat(index);
  }
  //图片缓冲区
  private bufferedimage createimage(){
    bufferedimage image=new bufferedimage(w, h, bufferedimage.type_int_bgr);
    graphics2d bi=(graphics2d) image.getgraphics();
    bi.setcolor(this.bgcolor);
    bi.fillrect(0, 0, w, h);
    return image;
  }
  //生成图片
  public bufferedimage getimage(){
    bufferedimage image=createimage();
    graphics2d bi=(graphics2d) image.getgraphics();
    stringbuilder sb=new stringbuilder();
    for (int i = 0; i <4; i++) {
      string string=randomchar()+"";
      sb.append(string);
      //每个字符占图片1/4宽
      float x=i*1.0f*w/4;
      //随机字体格式
      bi.setfont(randomfont());
      bi.setcolor(randomcolor());
      //把字写在图片适当处（h-6指图片距底部6个高度）
      bi.drawstring(string, x, h-6);
    }
    this.text=sb.tostring();
    drowline(image);
    return image;
  }
  //返回得到的字体
  public string gettext(){
    return text;
  }
  //把图片写入指定位置
  public static void output(bufferedimage image,outputstream out){
    try {
      imageio.write(image, "jpg", out);
    } catch (ioexception e) {
      e.printstacktrace();
    }
  }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。