问题

I am trying to use java.time.LocalDate in my android app, however if I try to import it, then any class from java.time gives a cannot resolve symbol error in Android studio 1.1

The only reason I could figure out for this is that it doesn't support java 8. Is that really the case?

回答1:

Android API level 26

Android API level 26 gained an implementation of java.time including your LocalDate class.

Earlier Android

For Android <26, alternatives include:

ThreeTen-Backport is a back-port of much of the java.time functionality to Java 6 & 7.
- ThreeTenABP adapts ThreeTen-Backport to Android.
Joda-Time is commonly used in Android projects. Joda-Time inspired the java.time package in Java 8, but they are not drop-in replacements. The Joda-Time team advises migration to java.time.

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

Java SE 8, Java SE 9, Java SE 10, and later
- Built-in.
- Part of the standard Java API with a bundled implementation.
- Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
- Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
- Later versions of Android bundle implementations of the java.time classes.
- For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….