1.首先新建兩個內容相同的檔案

2.建立測試類

public class TestMD5 {
    public static void main(String[] args) {
        try {
            FileInputStream file1 = new FileInputStream(new File("C:\\Users\\hp\\Desktop\\md51.txt"));
            FileInputStream file2 = new FileInputStream(new File("C:\\Users\\hp\\Desktop\\md52.txt"
 
));
            System.out.println(DigestUtil.md5Hex(file1));
            System.out.println(DigestUtil.md5Hex(file2));
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

列印結果:
202cb962ac59075b964b07152d234b70
202cb962ac59075b964b07152d234b70

3.修改md52.txt的內容

4.列印結果

202cb962ac59075b964b07152d234b70
81dc9bdb52d04dc20036dbd8313ed055