java存储图片

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.Calendar;
import java.util.Random;

import javax.servlet.http.HttpServletRequest;

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import sun.misc.BASE64Decoder;

public class ImageUntil {
    public boolean saveBase64File(String username,String imgStr) {
        // 对字节数组字符串进行Base64解码并生成图片
        if (imgStr == null) // 图像数据为空
            return false;
        imgStr = imgStr.replaceAll("data:image/jpeg;base64,", "");
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            // Base64解码
            byte[] b = decoder.decodeBuffer(imgStr);
            for (int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {// 调整异常数据
                    b[i] += 256;
                }
            }
            // 生成jpeg图片
            String fileName=username + ".jpg";
            HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
            File f2=new File(System.getProperty("catalina.home")+ File.separator+"webapps"+File.separator+"uploadFile");
            boolean exists2 = f2.exists();
            if(!exists2){
                f2.mkdirs();
            }
            //String realPath=request.getSession().getServletContext().getRealPath("uploadFile/touxiang")+ File.separator;
            String tomcaturl=System.getProperty("catalina.home")+ File.separator+"webapps"+File.separator+"uploadFile"+File.separator+"touxiang"+ File.separator;
            File f1=new File(System.getProperty("catalina.home")+ File.separator+"webapps"+File.separator+"uploadFile"+File.separator+"touxiang");
            boolean exists = f1.exists();
            if(!exists){
                f1.mkdirs();
            }
            File file = new File(tomcaturl+fileName);
            OutputStream out = new FileOutputStream(file);
            out.write(b);
            out.flush();
            out.close();
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
}

对字节数组字符串进行Base64解码并生成图片，imgData是从客户端发过来的，图片经过base64位处理的字符串，并将图片存在tomcat服务器根目录下