源码文件测试代码运行结果

源码文件

package com.lyc.noJs.util; import lombok.AllArgsConstructor; import lombok.NoArgsConstructor; import lombok.extern.slf4j.Slf4j; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; @Slf4j @NoArgsConstructor @AllArgsConstructor public class ImgMD5Util { private String imgPath = null; /** * 完成ImgMD5Util工具类的初始化操作 * @return */ public static ImgMD5Util newImgMD5Util(){ return new ImgMD5Util(); } /** * 有参初始化方法 * @param imgPath * @return */ public static ImgMD5Util newImgMD5Util(String imgPath){ return new ImgMD5Util(imgPath); } /** * 获取文件输入流 * @param imgPath * @return * @throws FileNotFoundException */ public InputStream getInputStream(String imgPath) throws FileNotFoundException { return new FileInputStream(imgPath); } /** * 获取图片文件的Digest * @param in * @return * @throws NoSuchAlgorithmException * @throws IOException */ public byte[] getImgDigest(InputStream in) throws NoSuchAlgorithmException, IOException { byte[] buffer = new byte[1024]; //如果想使用SHA-1或SHA-256，则传入SHA-1,SHA-256 MessageDigest complete = MessageDigest.getInstance("MD5"); if(in != null){ int numRead; do { numRead = in.read(buffer); //从文件读到buffer，最多装满buffer if (numRead > 0) { complete.update(buffer, 0, numRead); //用读到的字节进行MD5的计算，第二个参数是偏移量 } } while (numRead != -1); in.close(); } else { log.info("图片读取失败！"); return null; } return complete.digest(); } /** * 将byte[]类型的MD5转换成String类型的 * @param bytes * @return */ public String toMD5String(byte[] bytes){ StringBuffer mD5String = new StringBuffer(); for (int i = 0;i < bytes.length;i ++){ //加0x100是因为有的b[i]的十六进制只有1位 mD5String.append(Integer.toString( ( bytes[i] & 0xff ) + 0x100, 16).substring(1)); } return mD5String.toString(); } /** * 获取图片的MD5值 * @param imgPath * @return * @throws IOException * @throws NoSuchAlgorithmException */ public String getMD5(String imgPath) throws IOException, NoSuchAlgorithmException { //获取图片文件的输入流 InputStream in = getInputStream(imgPath); //获取图片文件的哈希值 byte[] bytes = getImgDigest(in); //将byte[]类型的MD5转换成String类型的 return toMD5String(bytes); } /** * 计算文件的MD5值 * @return * @throws IOException * @throws NoSuchAlgorithmException */ public String getMD5() throws IOException, NoSuchAlgorithmException{ return getMD5(imgPath); } }

测试代码

package com.lyc.demo; import com.lyc.noJs.util.ImgMD5Util; import lombok.extern.slf4j.Slf4j; import org.junit.Test; import java.io.IOException; import java.security.NoSuchAlgorithmException; @Slf4j public class ImgMD5Test { /** * 测试无参构造函数 * @throws IOException * @throws NoSuchAlgorithmException */ @Test public void test() throws IOException, NoSuchAlgorithmException { ImgMD5Util imgMD5Util = ImgMD5Util.newImgMD5Util(); String md5 = imgMD5Util.getMD5("D:\\WorkSpace\\no-js-parent\\no-js\\target\\no-js\\upload\\2018\\04\\09\\1523257445593.jpg"); log.info(md5); } /** * 测试有参构造函数 * @throws IOException * @throws NoSuchAlgorithmException */ @Test public void test2() throws IOException, NoSuchAlgorithmException { ImgMD5Util imgMD5Util = ImgMD5Util.newImgMD5Util("D:\\WorkSpace\\no-js-parent\\no-js\\target\\no-js\\upload\\2018\\04\\09\\1523257445593.jpg"); String md5 = imgMD5Util.getMD5(); log.info(md5); } }

运行结果

2018-04-09 15:19:28 INFO main com.lyc.demo.ImgMD5Test.test(ImgMD5Test.java:23) - 174b3302a43ad5fdd972a3d2e99ff78e 2018-04-09 15:19:28 INFO main com.lyc.demo.ImgMD5Test.test2(ImgMD5Test.java:35) - 174b3302a43ad5fdd972a3d2e99ff78e