JAVA實現讀取圖片

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package cn.kgc.ssm.common;

import java.io.*;

/**
 * @author
 * @create 2019-08-15 9:36
 **/
public class DDD {
    /**
     * 讀取圖片  返回一個圖片的字節數組
     * @param path
     * @return
     */
    public static byte[] imgArray(String path) {
        //字節輸入流
        InputStream inputStream = null;
        //字節緩沖流數組
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        try {
            inputStream = new FileInputStream(path);
            byte[] b = new byte[1024];
            int len = -1;
            //循環讀取
            while ((len = inputStream.read(b)) != 1) {
                byteArrayOutputStream.write(b, 0, len);
            }
            //返回byteArrayOutputStream數組
            return byteArrayOutputStream.toByteArray();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                //關閉流
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    public static void writeImg(byte[]array,String path){
        //創建一個字節輸出流
        DataOutputStream dataOutputStream = null;
        try {
            dataOutputStream = new DataOutputStream(new FileOutputStream(path));
            //將字節數組
            dataOutputStream.write(array);
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                //關閉
                dataOutputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 讀取二進制保存的圖片  放到數組里
     * @param path
     * @return
     */
    public static byte[] imageIn(String path){
        //創建一個字節輸出流
        DataInputStream dataInputStream = null;
        try {
            dataInputStream = new DataInputStream(new FileInputStream(path));
            //創建一個字節數組  byte的長度等於二進制圖片的返回的實際字節數
            byte[] b = new byte[dataInputStream.available()];
            //讀取圖片信息放入這個b數組
            dataInputStream.read(b);
            return b;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                //關閉流
                dataInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /**
     * 讀取二進制保存的圖片 輸出圖片
     * @param img
     * @param path
     */
    public static void writImg(byte[]img,String path){
        //創建一個字節輸出流
        OutputStream outputStream = null;
        try {
            outputStream = new FileOutputStream(path);
            //將圖片輸處到流中
            outputStream.write(img);
            //刷新
            outputStream.flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                //關閉
                outputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * main方法
     * @param args
     */
    public static void main(String[] args) {
        //獲取圖片  將圖片信息把存到數組b中
        byte[] b = DDD.imgArray("D:\\5.JPG");
        //通過數組B寫到文件中
        DDD.writImg(b,"img.txt");
        //讀取二進制文件保存到一個數組中
        byte[] c = DDD.imageIn("img.txt");
        //通過數組c  輸出圖片
        DDD.writImg(c,"img.jpg");
    }
}