首先，设置日期：LocalDateTime dateTime = LocalDateTime.of(2019, Month.SEPTEMBER, 9, 10, 20);现在，将日期时间格式化为 ISO_WEEK_DATE 格式：String str = dateTime.format(DateTimeFormatter.ISO_WEEK_DATE);示例import java.time.LocalDateTime; import java.time.Month; import java.time.format.DateTimeFormatter; public class Demo {    public static void main(String[] args) {       LocalDateTime dateTime = LocalDateTime.of(2019, Month.SEPTEMBER, 9, 10, 20);       System.out.println("DateTime = "+dateTime);       String str = dateTime.format(DateTimeFormatter.ISO_WEEK_DATE);       System.out.println("Formatted date = "+str);    } }输出DateTime = 2019-09-09T10:20 Formatted date = 2019-W37-1

首先，设置日期：LocalDateTime dateTime = LocalDateTime.of(2019, Month.JULY, 9, 10, 20);现在，将日期时间格式化为 ISO_DATE_TIME 格式：String str = dateTime.format(DateTimeFormatter.ISO_DATE_TIME);示例import java.time.LocalDateTime; import java.time.Month; import java.time.format.DateTimeFormatter; public class Demo {    public static void main(String[] args) {       LocalDateTime dateTime = LocalDateTime.of(2019, Month.JULY, 9, 10, 20);       System.out.println("DateTime = "+dateTime);       String str = dateTime.format(DateTimeFormatter.ISO_DATE_TIME);       System.out.println("Formatted date = "+str);    } }输出DateTime = 2019-07-09T10:20 Formatted date = 2019-07-09T10:20:00

要格式化和显示日期时间，您需要使用 DateTimeFormatter 并使用以下模式：DateTimeFormatter dtFormat = DateTimeFormatter.ofPattern("MMM dd yyyy hh:mm a z");上面，z 是时区：MMM dd yyyy hh:mm a z现在，对区域使用以下内容：ZonedDateTime dateTime = ZonedDateTime.now();示例import java.time.ZonedDateTime; import java.time.format.DateTimeFormatter; public class Demo {    public static void main(String[] argv) {       DateTimeFormatter dtFormat = DateTimeFormatter.ofPattern("MMM dd yyyy hh:mm a z");       ZonedDateTime dateTime = ZonedDateTime.now();       String res = dateTime.format(dtFormat);       System.out.printf("Date = %s %n", res);    } }输出Date = Apr 14 2019 01:35 PM IST

要格式化和显示日期时间，您需要使用 DateTimeFormatter。格式样式为 MEDIUM 和 SHORT：DateTimeFormatter formatter = DateTimeFormatter .ofLocalizedDateTime(FormatStyle.MEDIUM, FormatStyle.SHORT);显示格式化的日期：formatter.format(LocalDateTime.now()示例import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; import java.time.format.FormatStyle; public class Demo {    public static void main(String[] args) {       DateTimeFormatter formatter = DateTimeFormatter .ofLocalizedDateTime(FormatStyle.MEDIUM, FormatStyle.SHORT);       System.out.println("Formatted Date = "+formatter.format(LocalDateTime.now()));    } }输出Formatted Date = Apr 19, 2019, 1:27 PM

以下是我们的文件：Path p = Paths.get("E:/input.txt"); FileStore file = Files.getFileStore(p);现在，逐一检查支持的属性：FileAttributeView = file.supportsFileAttributeView(FileAttributeView.class) PosixFileAttributeView = file.supportsFileAttributeView(PosixFileAttributeView.class) BasicFileAttributeView = file.supportsFileAttributeView(BasicFileAttributeView.class)示例import java.nio.file.FileStore; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.nio.file.attribute.BasicFileAttributeView; import java.nio.file.attribute.FileAttributeView; import java.nio.file.attribute.FileOwnerAttributeView; import java.nio.file.attribute.PosixFileAttributeView; public class Demo {    public static void main(String[] args) throws Exception {       Path p = Paths.get("E:/input.txt");       FileStore file = Files.getFileStore(p);       System.out.println("FileAttributeView = " + file.supportsFileAttributeView(FileAttributeView.class));       System.out.println("PosixFileAttributeView = "+ file.supportsFileAttributeView(PosixFileAttributeView.class));       System.out.println("BasicFileAttributeView = "+ file.supportsFileAttributeView(BasicFileAttributeView.class));       System.out.println("FileOwnerAttributeView supported = "+ file.supportsFileAttributeView(FileOwnerAttributeView.class));   ... 阅读更多

假设以下列表不是只读的：List < Integer > list = new ArrayList < Integer > (); list.add(10); list.add(20); list.add(30); list.add(40); list.add(50); list.add(20); list.add(40); list.add(50);将上述列表转换为只读：list = Collections.unmodifiableList(list);转换后，您将无法再向列表中添加或删除元素。让我们看一个例子：以下程序将出错，因为我们首先将列表更新为只读，然后尝试从中删除一个元素，这现在是不可能的。原因是我们已将列表转换为只读，您无法再添加或删除元素 ... 阅读更多

要格式化并显示像这样的日期，即日/月/年，您需要设置模式：dd/MM/yyyy首先，设置一个 LocalDate：LocalDate localDate = LocalDate.now();现在将日期格式化为“12/04/2019”并显示：localDate.format(DateTimeFormatter.ofPattern("dd/MM/yyyy"))示例import java.time.LocalDate; import java.time.format.DateTimeFormatter; public class Demo {    public static void main(String[] args) {       LocalDate date = LocalDate.now();       System.out.println("Date = "+date);       DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/yyyy");       System.out.println("Formatted Date = "+date.format(formatter));    } }输出Date = 2019-04-12 Formatted Date = 12/04/2019

要格式化并显示像这样的日期，即年/月，您需要设置模式：uuuuMM首先，设置一个 LocalDate：LocalDate localDate = LocalDate.now();现在将日期格式化为“201904”并显示：localDate.format(DateTimeFormatter.ofPattern("uuuuMM"))示例import java.time.LocalDate; import java.time.format.DateTimeFormatter; public class Demo {    public static void main(String[] args) {       LocalDate localDate = LocalDate.now();       System.out.println("Date = "+localDate);       System.out.println("Date (Year and Month) = "+localDate.format(DateTimeFormatter.ofPattern("uuuuMM")));    } }输出Date = 2019-04-19 Date (Year and Month) = 201904

假设以下是对毫秒的声明：long millis = 5000000;现在从毫秒获取小时、分钟和秒：long hours = TimeUnit.MILLISECONDS.toHours(millis); long minutes = TimeUnit.MILLISECONDS.toMinutes(millis) - (hours * 60); long seconds = TimeUnit.MILLISECONDS.toSeconds(millis) - ((hours * 60 * 60) + (minutes * 60));使用 String.format() 将以上内容转换为可读字符串。示例import java.util.concurrent.TimeUnit; public class Demo {    public static void main(String[] argv){       long millis = 5000000;       long hours = TimeUnit.MILLISECONDS.toHours(millis);       long minutes = TimeUnit.MILLISECONDS.toMinutes(millis) - (hours * 60);       long seconds = TimeUnit.MILLISECONDS.toSeconds(millis) - ((hours * ... 阅读更多

首先设置一个 LocalDateTime：LocalDate date = LocalDate.now(); LocalTime time = LocalTime.now(); LocalDateTime dateTime = LocalDateTime.of(date, time);现在，将 LocalDateTime 转换为 LocalDate 和 LocalTime：LocalDate localDate = LocalDateTime.now().toLocalDate(); LocalTime localTime = LocalDateTime.now().toLocalTime();示例import java.time.LocalDate; import java.time.LocalDateTime; import java.time.LocalTime; public class Demo {    public static void main(String[] args) {       LocalDate date = LocalDate.now();       LocalTime time = LocalTime.now();       LocalDateTime dateTime = LocalDateTime.of(date, time);       System.out.println("DateTime = "+dateTime);       LocalDate localDate = LocalDateTime.now().toLocalDate();       LocalTime localTime = LocalDateTime.now().toLocalTime();       System.out.println("Date = "+localDate);       System.out.println("Time = ... 阅读更多