StringBuffer buffer1 = new StringBuffer( nombre[i] );
buffer1.setLength(10); //10 caracteres para el nombre
file.writeChars(buffer1.toString());//insertar nombre
StringBuffer buffer2 = new StringBuffer( cargo[i] );
buffer2.setLength(10); //10 caracteres para el cargo
file.writeChars(buffer2.toString());//10 caracteres para el cargo
file.writeChars(cargo[i]); //insertar cargo
file.writeInt(salario[i]);//insertar salario