java - A file equals content of website? -

i couldnt find out how compare content of specific file content of website.

this code used check, if equals:

 private static boolean equals() {     try {         return new string(files.readallbytes(paths.get(filepath))).equals(getfile());     } catch (exception e) {         return false;     } } 

filepath:

private static final string filepath = "test.txt"; 

getfile():

private static string getfile() {     try {         url pageurl = new url(simpleurl);         urlconnection uc = pageurl.openconnection();         stringbuilder text = new stringbuilder();         try (scanner scanner = new scanner(uc.getinputstream(), "utf-8")) {             while (scanner.hasnextline()) {                 text.append(scanner.nextline()).append("\n");             }         }         return text.tostring();     } catch (exception ex) {         return null;     } } 

the method #equals() keeps returning false while content matches file.

you're unnecessarily massaging bytes characters , , hereby losing information contained in original bytes. usually, should transform bytes characters when interested in reading or manipulating bytes on per-character basis and absolutely understand how character encodings work. neither of seems case here. should reading , writing raw , unmodified bytes instead of transforming them characters.

to read inputstream url byte[] (instead of string), 1 of ways be:

bytearrayoutputstream output = new bytearrayoutputstream();  try (inputstream input = url.openstream()) {     byte[] buffer = new byte[10240];     (int length = 0; (length = input.read(buffer)) > 0;) {         output.write(buffer, 0, length));     } }  byte[] contentfromurl = output.tobytearray(); 

(apache commons io , google guava have oneliner methods this)

note when intend save byte[] file, should merely doing follows without need massage them characters new string() or so:

files.write(path, contentfromurl); 

also note when intend save inputstream file without need intermediairy byte[], should doing in first place:

try (inputstream input = url.openstream()) {     files.copy(input, path); } 

either way, end file containing exactly same bytes obtained. based on code, know can byte[] out of follows:

byte[] contentfromfile = files.readallbytes(path); 

if have content byte[] , want compare against byte[], should using arrays#equals() without massaging them strings:

arrays.equals(contentfromurl, contentfromfile); 

that's all. there no need explicitly read using character encoding of haven't confirmed http response been encoded in that encoding, , there no need swallow newlines , replace them fixed 1 of haven't confirmed http response using that newline character.