获取本周第一天和最后一天可以使用Java中的Calendar类和SimpleDateFormat类来实现。具体步骤如下:
1. 获取当前日期
```
Calendar calendar = Calendar.getInstance();
```
2. 将日期设置为本周第一天(星期日)
```
calendar.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
```
3. 获取本周第一天并格式化为yyyy-MM-dd格式
```
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String firstDayOfWeek = sdf.format(calendar.getTime());
System.out.println("本周第一天:" + firstDayOfWeek);
```
4. 将日期设置为下周第一天,再减去1天,获取本周最后一天并格式化为yyyy-MM-dd格式
```
calendar.add(Calendar.WEEK_OF_YEAR, 1);
calendar.add(Calendar.DATE, -1);
String lastDayOfWeek = sdf.format(calendar.getTime());
System.out.println("本周最后一天:" + lastDayOfWeek);
```
完整示例代码如下:
```
import java.text.SimpleDateFormat;
import java.util.Calendar;
public class DateDemo {
public static void main(String[] args) {
Calendar calendar = Calendar.getInstance();
// 获取本周第一天
calendar.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String firstDayOfWeek = sdf.format(calendar.getTime());
System.out.println("本周第一天:" + firstDayOfWeek);
// 获取本周最后一天
calendar.add(Calendar.WEEK_OF_YEAR, 1);
calendar.add(Calendar.DATE, -1);
String lastDayOfWeek = sdf.format(calendar.getTime());
System.out.println("本周最后一天:" + lastDayOfWeek);
}
}
```