英文:
How to write file path into txt.file?
问题
public class FileScanner {
public void scanFolder() throws IOException, InterruptedException {
Scanner input = new Scanner(System.in);
// Creating log file
File log = new File("C:/Users/mateu/OneDrive/Pulpit/log.txt");
if (!log.exists()) {
log.createNewFile();
}
// Object for writing file names and paths to the log
PrintWriter printIntoLog = new PrintWriter(log);
while (true) {
// Providing path of the file to search for
System.out.println("Input file's directory you are looking for: ");
String path = input.nextLine();
// Creating object for the given file
File searchedFile = new File(path);
// Checking if the file exists - if yes, writing its path to the log and deleting it
try {
if (searchedFile.exists()) {
printIntoLog.println(searchedFile.getPath());
//searchedFile.delete();
} else {
throw new MyFileNotFoundException("Searching stopped for 1 minute.");
}
} catch (MyFileNotFoundException ex) {
System.out.println(ex);
TimeUnit.MINUTES.sleep(1);
}
}
}
}
英文:
I am writing simple program that is looking for file and if it exists, writes his path to txt file. If not, program is freezed for 1 minute. My problem is that file path is not being printed into txt file when searched file exists. I think it is something wrong with try block. I do not know where the problem is. How can i solve it?
public class FileScanner {
public void scanFolder() throws IOException, InterruptedException {
Scanner input = new Scanner(System.in);
//tworzenie pliku logu
File log = new File("C:/Users/mateu/OneDrive/Pulpit/log.txt");
if (!log.exists()) {
log.createNewFile();
}
//obiekt zapisujacy nazwy i sciezki plikow do logu
PrintWriter printIntoLog = new PrintWriter(log);
while (true) {
//podanie sciezki szukanego pliku
System.out.println("Input file's directory you are looking for: ");
String path = input.nextLine();
//utworzenie obiektu do danego pliku
File searchedFile = new File(path);
//sprawdzenie czy plik istnieje- jesli tak to zapisuje do logu jego sciezke i usuwa go
try{
if (searchedFile.exists()) {
printIntoLog.println(searchedFile.getPath());
//searchedFile.delete();
}else{
throw new MyFileNotFoundException("Searching stopped for 1 minute.");
}
}catch(MyFileNotFoundException ex){
System.out.println(ex);
TimeUnit.MINUTES.sleep(1);
}
}
}
}
答案1
得分: 0
你应该在执行结束之前关闭 PrintWriter 引用。在对文件进行读写操作后关闭文件是一种强制性的实践。
如果你使用的是 Java +7，你可以使用 try-with-resources 语法来实现这一点：
try (PrintWriter printIntoLog = new PrintWriter(log)) {
while (true) {
....
}
}
对于旧版本的 Java，你可以使用 try-finally 语法：
try {
while(true) {
...
}
} finally {
printIntoLog.close();
}
参考：
英文:
You should close the PrintWriter reference before finishing execution. It's an enforced practice to close a file after read/write on it.
If you are using Java +7 you can use the fancy way withtry-with-resources syntax
```java
try (PrintWriter printIntoLog = new PrintWriter(log)) {
while (true) {
....
}
}
```
With older versions you can use try-finally syntax
try {
while(true) {
...
}
} finally {
printIntoLog.close();
}
See
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