yyyy-MM-dd -> LocalDateTime
直接把yyyy-MM-dd格式的日期字符串解析成LocalDateTime会抛出异常
try {
LocalDateTime localDateTime = LocalDateTime.parse("2019-05-27", DateTimeFormatter.ofPattern("yyyy-MM-dd"));
System.out.println(localDateTime);
} catch (Exception ex) {
ex.printStackTrace();
}
抛出如下异常
java.time.format.DateTimeParseException: Text '2019-05-27' could not be parsed: Unable to obtain LocalDateTime from TemporalAccessor: {},ISO resolved to 2019-05-27 of type java.time.format.Parsed
at java.time.format.DateTimeFormatter.createError(DateTimeFormatter.java:1919)
at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1854)
at java.time.LocalDateTime.parse(LocalDateTime.java:492)
at com.ahut.common.utils.DateTest.testLocalDate(DateTest.java:28)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.time.DateTimeException: Unable to obtain LocalDateTime from TemporalAccessor: {},ISO resolved to 2019-05-27 of type java.time.format.Parsed
at java.time.LocalDateTime.from(LocalDateTime.java:461)
at java.time.LocalDateTime$$Lambda$7/762152757.queryFrom(Unknown Source)
at java.time.format.Parsed.query(Parsed.java:226)
at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1850)
... 24 more
Caused by: java.time.DateTimeException: Unable to obtain LocalTime from TemporalAccessor: {},ISO resolved to 2019-05-27 of type java.time.format.Parsed
at java.time.LocalTime.from(LocalTime.java:409)
at java.time.LocalDateTime.from(LocalDateTime.java:457)
... 27 more
解决办法yyyy-MM-dd -> LocalDate -> LocalDateTime
try {
LocalDate localDate = LocalDate.parse("2019-05-27", DateTimeFormatter.ofPattern("yyyy-MM-dd"));
LocalDateTime localDateTime = localDate.atStartOfDay();
System.out.println(localDateTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
} catch (Exception ex) {
ex.printStackTrace();
}
输出
2019-05-27 00:00:00
LocalDate atStartOfDay方法源码
/**
* Combines this date with the time of midnight to create a {@code LocalDateTime}
* at the start of this date.
* <p>
* This returns a {@code LocalDateTime} formed from this date at the time of
* midnight, 00:00, at the start of this date.
*
* @return the local date-time of midnight at the start of this date, not null
*/
public LocalDateTime atStartOfDay() {
return LocalDateTime.of(this, LocalTime.MIDNIGHT);
}
LocalTime常量
/**
* The minimum supported {@code LocalTime}, '00:00'.
* This is the time of midnight at the start of the day.
*/
public static final LocalTime MIN;
/**
* The maximum supported {@code LocalTime}, '23:59:59.999999999'.
* This is the time just before midnight at the end of the day.
*/
public static final LocalTime MAX;
/**
* The time of midnight at the start of the day, '00:00'.
*/
public static final LocalTime MIDNIGHT;
/**
* The time of noon in the middle of the day, '12:00'.
*/
public static final LocalTime NOON;
/**
* Constants for the local time of each hour.
*/
private static final LocalTime[] HOURS = new LocalTime[24];
扩展
获取当前日期最早时间和最晚时间
System.out.println(LocalDateTime.of(LocalDate.now(), LocalTime.MIN).format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
System.out.println(LocalDateTime.of(LocalDate.now(), LocalTime.MAX).format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
2019-05-27 00:00:00 2019-05-27 23:59:59
封装解析方法
/**
* desc :
* create_user : cheng
* create_date : 2019/5/27 19:28
*/
private LocalDateTime parseToLocalDateTime(String str, String pattern) {
if (StringUtils.isAnyBlank(str, pattern)) {
return null;
}
LocalDateTime localDateTime;
try {
localDateTime = LocalDateTime.parse(str, DateTimeFormatter.ofPattern(pattern));
} catch (Exception ex) {
ex.printStackTrace();
LocalDate localDate = parseLocalDate(str, pattern);
localDateTime = Objects.isNull(localDate) ? null : localDate.atStartOfDay();
}
return localDateTime;
}
/**
* desc :
* create_user : cheng
* create_date : 2019/5/27 19:30
*/
private LocalDate parseLocalDate(String str, String pattern) {
if (StringUtils.isAnyBlank(str, pattern)) {
return null;
}
LocalDate localDate = null;
try {
localDate = LocalDate.parse(str, DateTimeFormatter.ofPattern(pattern));
} catch (Exception ex) {
ex.printStackTrace();
}
return localDate;
}
调用
System.out.println("解析: " + parseToLocalDateTime("2019-05-27", "yyyy-MM-dd")
.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
结果
解析: 2019-05-27 00:00:00