Java backend implements code example to save base64 string as image

import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
import sun.misc.BASE64Decoder; 
import sun.misc.BASE64Encoder; 
public class Base64Test  
{ 
  public static void main(String[] args) 
  { 
    String strImg = GetImageStr(); 
    System.out.println(strImg); 
    GenerateImage(strImg); 
  } 
  //图片转化成base64字符串 
  public static String GetImageStr() 
  {//将图片文件转化为字节数组字符串，并对其进行Base64编码处理 
    String imgFile = "D:\\tupian\\a.jpg";//待处理的图片 
    InputStream in = null; 
    byte[] data = null; 
    //读取图片字节数组 
    try  
    { 
      in = new FileInputStream(imgFile);     
      data = new byte[in.available()]; 
      in.read(data); 
      in.close(); 
    }  
    catch (IOException e)  
    { 
      e.printStackTrace(); 
    } 
    //对字节数组Base64编码 
    BASE64Encoder encoder = new BASE64Encoder(); 
    return encoder.encode(data);//返回Base64编码过的字节数组字符串 
  } 
   
  //base64字符串转化成图片 
  public static boolean GenerateImage(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; 
    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 imgFilePath = "D:\\tupian\\new.jpg";//新生成的图片 
      OutputStream out = new FileOutputStream(imgFilePath);   
      out.write(b); 
      out.flush(); 
      out.close(); 
      return true; 
    }  
    catch (Exception e)  
    { 
      return false; 
    } 
  } 
}