Fitxers - IO

name: portada
class: portada-slide, center, middle

# Fitxers - IO

.footnote[Joan Puigcerver Ibáñez]

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layout: true
class: regular-slide
.right[.logo[![logoMislata](/itb/images/logo_mislata.png)]]

---
# Fitxer -> String

#### Javadoc Files
```
public static String readString(Path path) throws IOException
```

#### Exemple
```
String s = Files.readString(path);
System.out.println("s = " + s);
```

---
# String -> Fitxer

#### Javadoc Files
```
static Path   writeString(Path path, CharSequence csq, OpenOption... options)
```

#### Exemple
```
Path path = Files.createTempFile("some", ".txt");
Files.writeString(path, "this is my string");

Path anotherUtf8File = Files.createTempFile("some", ".txt");
Files.writeString(anotherUtf8File, "this is my string2", StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE);
```

---
# OpenOptions
- [StandardOpenOption](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/nio/file/StandardOpenOption.html)
- [LinkOption](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/nio/file/LinkOption.html)

---
# Fitxer -> Scanner

```
Scanner scanner = new Scanner(path);
while(scanner.hasNext()){
    String word = scanner.next();
    System.out.println(word);
}
```

---
# PrintStream
Escriure en un fitxer

```
Path path = Paths.get("somefile.txt");
try (OutputStream outputStream = Files.newOutputStream(path, StandardOpenOption.APPEND, StandardOpenOption.CREATE)) {
    PrintStream printStream = new PrintStream(outputStream, true);
    printStream.println("HELLO!");
}
```

???

```
public class Book implements Serializable {
  //...
}
```

?---
# classe -> fitxer

```
FileOutputStream fileOutputStream = new FileOutputStream(FILE_PATH);
ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);
objectOutputStream.writeObject(objectToStore);
objectOutputStream.flush();
objectOutputStream.close();
```

?---
# fitxer -> classe

```
FileInputStream fileInputStream = new FileInputStream(FILE_PATH);
ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
MyObjectClass storedObjecy = (MyObjectClass) objectInputStream.readObject();
objectInputStream.close();
```

# Escriptura Streams

```
try (BufferedWriter bufferedWriter = Files.newBufferedWriter(utfFile)) {
    // handle reader
}

try (OutputStream os = Files.newOutputStream(utfFile)) {
    // handle outputstream
}
```

# How to read strings from files

```
String s = Files.readString(utfFile);// UTF 8
System.out.println("s = " + s);
```

# Read Strig with buffer
```
try (BufferedReader bufferedReader = Files.newBufferedReader(utfFile)) {
    // handle reader
}

try (InputStream is = Files.newInputStream(utfFile)) {
    // handle inputstream
}

Biblio: https://www.marcobehler.com/guides/java-files
```