java读写图片和字符串转换

  // 将字符串转换成二进制，用于显示图片   
        byte[] imgByte = hex2byte( imgStr );   
        InputStream in = new ByteArrayInputStream( imgByte );   
        byte[] b = new byte[1024];   
        int nRead = 0;   
           
        OutputStream o = response.getOutputStream();   
           
        while( ( nRead = in.read(b) ) != -1 ){   
            o.write( b, 0, nRead );   

 

 

 

 

        }   
           
        o.flush();   
        o.close();   
           
        in.close();   
           
    }catch(Exception e){   
        e.printStackTrace();   
    } 

 

public String getImgFromByte() {
//业务逻辑取得图片的byte[] 数据

                .......

InputStream buffin = new ByteArrayInputStream(/*byte[]数据*/);
String str= picUrl.getImageType();  
               String imgtype[] = str.split("/"); 
BufferedImage img;
try {
img = ImageIO.read(buffin);
// 禁止图像缓存。
this.getResponse().setHeader("Pragma", "no-cache");
this.getResponse().setHeader("Cache-Control", "no-cache");
this.getResponse().setDateHeader("Expires", 0);
this.getResponse().setContentType(picUrl.getImageType());

// 将图像输出到Servlet输出流中。
ServletOutputStream sos;
sos = this.getResponse().getOutputStream();
ImageIO.write(img, imgtype[1], sos);
sos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}

jsp页面

<img src="getUserIcon!getImgFromByte.action"/></span>

struts.xml只需配置acton跳转即可