java判断文件是否存在

import java.net.HttpURLConnection;
import java.net.URL;

public boolean checkRemoteFile(String fileUrl){
boolean flag = true;
try {
URL serverUrl = new URL(fileUrl);
HttpURLConnection urlcon = (HttpURLConnection) serverUrl.openConnection();

String message = urlcon.getHeaderField(0);//文件存在‘HTTP/1.1 200 OK’ 文件不存在 ‘HTTP/1.1 404 Not Found’
if(message != null && !"".equals(message)){
if (message.startsWith("HTTP/1.1 404")) {
flag = false;
}
}else{
flag = false;
}
} catch (Exception e) {
e.printStackTrace();
flag = false;
}
return flag;
}

import java.io.File;

public boolean checkLocalFile(String filePath){
boolean  flag = true;
File file = new File(filePath);
if(!file.exists()) {
flag = false;
}
return flag;
}