どのように2つのファイルがそれと同じであるかどうかを判断するためにJavaを使用するには?私のアプローチがあります
(1)最初の二つの文書の内容の長さを比較します。
(2)同じ長さ、MD5値の場合には、その後、2つのファイルを比較します。
導入されるジャーパッケージの必要性:
<依存性>
<のgroupId>コモンズコーデック</のgroupId>
<たartifactId>コモンズコーデック</たartifactId>
<バージョン> 1.11 </バージョン>
</依存>
2つのファイルが同じバイトストリームであるかどうかを確認するための機能を提供します。
/ **
*ストリームは、ファイルの2バイトに等しいかどうかを確認
* @return 真のブール等しい
* @throws のIOException
* /
プライベート 静的 ブール isSameFiles(バイト [] fileByte1、バイト[] fileByte2){
文字列firstFileMd5 = DigestUtils.md5Hex(fileByte1) ;
文字列secondFileMd5 = DigestUtils.md5Hex(fileByte2);
IF (firstFileMd5.equals(secondFileMd5)){
するSystem.out.println( "---- ------ MD5等しい" + firstFileMd5);
戻り trueに;
}他{
するSystem.out.println(firstFileMd5 +は+ "firstFileMd5 ++不等++ secondFileMd5 =である" secondFileMd5)。
リターン はfalse ;
}
}
ビットのbase64文字列をファイルに等しいかどうかをチェックします
バイト配列に文字列に直接転送して、関数isSameFilesを呼び出します。
パブリック 静的 ボイドメイン(文字列[]引数)がスローにIOException {
// TODO自動生成方法スタブを
文字列のIMG = "iVBORw0KGgoAAAANSUhEUgAAApsAAAEPCAYAAAANjQ + sAAAOqUlEQVR4Xu3WMREAAAgDMerfNCp CwI65Bh + + + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt 5wgQIECAAAECBAhEAot2zRIgQIAAAQIECBA4sekJCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + + + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQ gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJtIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + + + gAABAgQIECBAIBMQmxmt gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + + + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt +gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + + + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGx gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJtmdEaJkCAAAECBAgQEJt + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + + + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAAB gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJtsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDIBsZnRGiZAgAABAgQIEBCbfoAAAQIECBAgQCATEJsZrWECBAgQIECAAAGx6QcIECBAgAABAgQyAbGZ0RomQIAAAQIECBAQm36AAAECBAgQIEAgExCbGa1hAgQIECBAgAABsekHCBAgQIAAAQIEMgGxmdEaJkCAAAECBAgQEJt + gAABAgQIECBAIBMQmxmtYQIECBAgQIAAAbHpBwgQIECAAAECBDKBB16TARB6VWp0AAAAAElFTkSuQmCC」;
文字列imgReal = "iVBOI =" ;
BASE64Decoderデコーダ = 新しいBASE64Decoder()。
もし(isBase64(IMG)){
するSystem.out.println( "IMGベース64" )。
}
であれば(isBase64(imgReal)){
するSystem.out.println( "imgRealベース64" )。
}
バイト [] imageByteArray = NULL ;
試す{
imageByteArray = decoder.decodeBuffer(IMG)。
System.out.println(isSameFiles(imageByteArray、decoder.decodeBuffer(imgReal)))。
} キャッチ(IOExceptionを電子){
e.printStackTrace();
}
のSystem.out.println(chechFile())。
}
二つの文書が等しいかどうかを確認する2
ファイルを読んだ後、バイトストリームに変換:
/**
* 检查两个文件是否相等,假设 C:\Users\Pictures目录下有两个图片文件
* @return boolean true 相等
* @throws IOException
*/
private static boolean chechFile() throws IOException {
File file1 = new File("C:\\Users\\Pictures\\test1.jpg");
File file2 = new File("C:\\Users\\Pictures\\test2.jpg");
if (file1.length() != file2.length()) {
System.out.println("+++++++++ unequal +++++++++++++");
return false;
}
InputStream fileStream1 = new FileInputStream(file1);
InputStream fileStream2 = new FileInputStream(file2);
// InputStream 转 byte[]
byte[] imageByteArray = new byte[fileStream1.available()];
System.out.println(isSameFiles(imageByteArray, new byte[fileStream2.available()]));
return true;
}
以上方法验证小文件妥妥的,大文件请移步:《JAVA MD5 验证大文件(改)》
Reference
https://blog.csdn.net/wxz980927155/article/details/82257225
https://www.cnblogs.com/DylanZ/p/6269042.html