Java : BufferedWriter con ejemplos

final var path = Path.of("R:", "java-work", "aaa.txt");
System.out.println(path); // R:\java-work\aaa.txt
System.out.println(Files.notExists(path)); // true

try (final var writer = Files.newBufferedWriter(path)) {

    writer.write("abcd");
    writer.newLine();

    writer.write("XYZ");
    writer.newLine();

    writer.write("12345");
    writer.newLine();
}

final var str = Files.readString(path);
System.out.println(str);

// Result
// ↓
//abcd
//XYZ
//12345

lock

Consulte el siguiente enlace.

• Writer con ejemplos

BufferedWriter (Writer out)

Crea un flujo de salida de caracteres almacenado en búfer que utiliza un búfer de salida de tamaño predeterminado. (Traducción automática)

final var sw = new StringWriter();
try (final var writer = new BufferedWriter(sw)) {

    writer.write("abcd");
    writer.write("XYZ");
}

System.out.println(sw); // abcdXYZ

BufferedWriter (Writer out, int sz)

Crea una nueva secuencia de salida de caracteres almacenada en búfer que utiliza un búfer de salida del tamaño indicado. (Traducción automática)

final var sw = new StringWriter();
try (final var writer = new BufferedWriter(sw, 128)) {

    writer.write("abcd");
    writer.write("XYZ");
}

System.out.println(sw); // abcdXYZ

void close ()

Cierra el flujo, lavándolo primero. (Traducción automática)

final var path = Path.of("R:", "java-work", "aaa.txt");
System.out.println(path); // R:\java-work\aaa.txt

try (final var writer = Files.newBufferedWriter(path)) {
    writer.append("abcd");
}

final var str = Files.readString(path);
System.out.println(str); // abcd

// An example without a try-with-resources statement.
final var path = Path.of("R:", "java-work", "aaa.txt");
System.out.println(path); // R:\java-work\aaa.txt

final var writer = Files.newBufferedWriter(path);
try {
    writer.append("abcd");
} finally {
    writer.close();
}

final var str = Files.readString(path);
System.out.println(str); // abcd

void flush ()

Limpia la corriente. (Traducción automática)

final var sw = new StringWriter();
try (final var writer = new BufferedWriter(sw, 128)) {

    writer.write("abcdXYZ");
    System.out.println(sw.toString().isEmpty()); // true

    writer.flush();
    System.out.println(sw); // abcdXYZ
}

final var sw = new StringWriter();
try (final var writer = new BufferedWriter(sw, 4)) {

    writer.write("abcdXYZ");
    System.out.println(sw); // abcd

    writer.flush();
    System.out.println(sw); // abcdXYZ
}

void newLine ()

Escribe un separador de línea. (Traducción automática)

final var path = Path.of("R:", "java-work", "aaa.txt");
System.out.println(path); // R:\java-work\aaa.txt

try (final var writer = Files.newBufferedWriter(path)) {

    writer.write("abcd");
    writer.write("XYZ");

    writer.newLine();

    writer.write("12345");
}

final var str = Files.readString(path);
System.out.println(str);

// Result
// ↓
//abcdXYZ
//12345

void write (char[] cbuf, int off, int len)

Escribe una parte de una matriz de caracteres. (Traducción automática)

final char[] cbuf = {'a', 'b', 'c', 'd'};

final var sw1 = new StringWriter();
try (final var writer = new BufferedWriter(sw1)) {
    writer.write(cbuf, 0, 1);
}
System.out.println(sw1); // a

final var sw2 = new StringWriter();
try (final var writer = new BufferedWriter(sw2)) {
    writer.write(cbuf, 0, 2);
}
System.out.println(sw2); // ab

final var sw3 = new StringWriter();
try (final var writer = new BufferedWriter(sw3)) {
    writer.write(cbuf, 0, 3);
}
System.out.println(sw3); // abc

final var sw4 = new StringWriter();
try (final var writer = new BufferedWriter(sw4)) {
    writer.write(cbuf, 0, 4);
}
System.out.println(sw4); // abcd

final char[] cbuf = {'a', 'b', 'c', 'd'};

final var sw1 = new StringWriter();
try (final var writer = new BufferedWriter(sw1)) {
    writer.write(cbuf, 0, 4);
}
System.out.println(sw1); // abcd

final var sw2 = new StringWriter();
try (final var writer = new BufferedWriter(sw2)) {
    writer.write(cbuf, 1, 3);
}
System.out.println(sw2); // bcd

final var sw3 = new StringWriter();
try (final var writer = new BufferedWriter(sw3)) {
    writer.write(cbuf, 2, 2);
}
System.out.println(sw3); // cd

final var sw4 = new StringWriter();
try (final var writer = new BufferedWriter(sw4)) {
    writer.write(cbuf, 3, 1);
}
System.out.println(sw4); // d

void write (int c)

Escribe un solo caracter. (Traducción automática)

final var sw = new StringWriter();
try (final var writer = new BufferedWriter(sw)) {
    writer.write('a');
    writer.write('b');
    writer.write('c');
    writer.write('d');
    writer.write('X');
    writer.write('Y');
    writer.write('Z');
}

System.out.println(sw); // abcdXYZ

void write (String s, int off, int len)

Escribe una parte de una cadena. (Traducción automática)

final var str = "abcd";

final var sw1 = new StringWriter();
try (final var writer = new BufferedWriter(sw1)) {
    writer.write(str, 0, 1);
}
System.out.println(sw1); // a

final var sw2 = new StringWriter();
try (final var writer = new BufferedWriter(sw2)) {
    writer.write(str, 0, 2);
}
System.out.println(sw2); // ab

final var sw3 = new StringWriter();
try (final var writer = new BufferedWriter(sw3)) {
    writer.write(str, 0, 3);
}
System.out.println(sw3); // abc

final var sw4 = new StringWriter();
try (final var writer = new BufferedWriter(sw4)) {
    writer.write(str, 0, 4);
}
System.out.println(sw4); // abcd

final var str = "abcd";

final var sw1 = new StringWriter();
try (final var writer = new BufferedWriter(sw1)) {
    writer.write(str, 0, 4);
}
System.out.println(sw1); // abcd

final var sw2 = new StringWriter();
try (final var writer = new BufferedWriter(sw2)) {
    writer.write(str, 1, 3);
}
System.out.println(sw2); // bcd

final var sw3 = new StringWriter();
try (final var writer = new BufferedWriter(sw3)) {
    writer.write(str, 2, 2);
}
System.out.println(sw3); // cd

final var sw4 = new StringWriter();
try (final var writer = new BufferedWriter(sw4)) {
    writer.write(str, 3, 1);
}
System.out.println(sw4); // d

append, append, append, nullWriter, write, write

Consulte el siguiente enlace.

• Writer con ejemplos