JAVA实现读取图片

话不读说  直接上代码

 package cn.kgc.ssm.common;

 import java.io.*;

 /**
  * @author
  * @create 2019-08-15 9:36
  **/
 public class DDD {
     /**
      * 读取图片  返回一个图片的字节数组
      * @param path
      * @return
      */
     public static byte[] imgArray(String path) {
         //字节输入流
         InputStream inputStream = null;
         //字节缓冲流数组
         ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
         try {
             inputStream = new FileInputStream(path);
             byte[] b = new byte[1024];
             int len = -1;
             //循环读取
             while ((len = inputStream.read(b)) != 1) {
                 byteArrayOutputStream.write(b, 0, len);
             }
             //返回byteArrayOutputStream数组
             return byteArrayOutputStream.toByteArray();
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             try {
                 //关闭流
                 inputStream.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
         return null;
     }

     public static void writeImg(byte[]array,String path){
         //创建一个字节输出流
         DataOutputStream dataOutputStream = null;
         try {
             dataOutputStream = new DataOutputStream(new FileOutputStream(path));
             //将字节数组
             dataOutputStream.write(array);
         } catch (IOException e) {
             e.printStackTrace();
         }finally {
             try {
                 //关闭
                 dataOutputStream.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

     /**
      * 读取二进制保存的图片  放到数组里
      * @param path
      * @return
      */
     public static byte[] imageIn(String path){
         //创建一个字节输出流
         DataInputStream dataInputStream = null;
         try {
             dataInputStream = new DataInputStream(new FileInputStream(path));
             //创建一个字节数组  byte的长度等于二进制图片的返回的实际字节数
             byte[] b = new byte[dataInputStream.available()];
             //读取图片信息放入这个b数组
             dataInputStream.read(b);
             return b;
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }finally {
             try {
                 //关闭流
                 dataInputStream.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
         return null;
     }

     /**
      * 读取二进制保存的图片 输出图片
      * @param img
      * @param path
      */
     public static void writImg(byte[]img,String path){
         //创建一个字节输出流
         OutputStream outputStream = null;
         try {
             outputStream = new FileOutputStream(path);
             //将图片输处到流中
             outputStream.write(img);
             //刷新
             outputStream.flush();
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }finally {
             try {
                 //关闭
                 outputStream.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
     }

     /**
      * main方法
      * @param args
      */
     public static void main(String[] args) {
         //获取图片  将图片信息把存到数组b中
         byte[] b = DDD.imgArray("D:\\5.JPG");
         //通过数组B写到文件中
         DDD.writImg(b,"img.txt");
         //读取二进制文件保存到一个数组中
         byte[] c = DDD.imageIn("img.txt");
         //通过数组c  输出图片
         DDD.writImg(c,"img.jpg");
     }
 }