java.lang.NoClassDefFoundError: Failed resolution of: Ljava/time/LocalDate; error

问题

I tried everything, but the error not getting solved

Here is my code:

public String[] getWeekDays() {

    LocalDate today = LocalDate.now();
    LocalDate monday = today;
    LocalDate tue = today;
    LocalDate wed = today;
    LocalDate thur = today;
    LocalDate fri = today;
    LocalDate sat = today;
    LocalDate sunday = today;
    while (sunday.getDayOfWeek() != DayOfWeek.SUNDAY){
        sunday = sunday.minusDays(1);
     }
     while (monday.getDayOfWeek() != DayOfWeek.MONDAY){
        monday = monday.minusDays(1);
     }
     while (tue.getDayOfWeek() != DayOfWeek.TUESDAY){
        tue = tue.plusDays(1);
     }
     while (wed.getDayOfWeek() != DayOfWeek.WEDNESDAY){
        wed = wed.plusDays(1);
     }
     while (thur.getDayOfWeek() != DayOfWeek.THURSDAY){
        thur = thur.plusDays(1);
     }
     while (fri.getDayOfWeek() != DayOfWeek.FRIDAY){
        fri = fri.plusDays(1);
     }
     while (sat.getDayOfWeek() != DayOfWeek.SATURDAY){
        sat = sat.plusDays(1);
     }

     String[] days = {String.valueOf(sunday),String.valueOf(monday), String.valueOf(tue), String.valueOf(wed),
                String.valueOf(thur), String.valueOf(fri), String.valueOf(sat)};
    return days;
}

I have written the code to get dates of one week. When I running this code, i am getting an error at LocalDate.now();. The error is "java.lang.NoClassDefFoundError: Failed resolution of: Ljava/time/LocalDate;". I have searched on the net. Some are saying it requires API level min 27. I have tired on API 27 level but the error didn't get resolved. More ever my target device is API 26 I needed to run on this API level. And also tried adding "compile "java.time:LocalTime:1.8" ". This one also doesn't work. Please help me...

回答1:

NoClassDefFoundError-Thrown if the Java Virtual Machine or a ClassLoader instance tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found.

LocalDate today = LocalDate.now(); // Added 1.8

Read LocalDate

Make sure, You added this in your build.gradle section.

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
    }

FYI

java.time package was added only in API 26.

So, You should set

 minSdkVersion 26

After that, Clean-Rebuild-Gradle.

回答2:

You are trying to run your app on a device (or simulator) with an API level below 26. LocalDate and the rest of java.time were introduced in level 26. However, there is a backport that allows you to use the most used 80 % of it on earlier Android versions. I suggest that this is a good solution for you.

So add the ThreeTenABP library to your project. And make sure you import org.threeten.bp.LocalDate and org.threeten.bp.DayOfWeek rather than the versions from java.time. Then you should be fine.

I was once told that dependencies is (I didn’t test):

compile group: 'org.threeten', name: 'threetenbp', version: '1.3.3', classifier: 'no-tzdb'

TemporalAdjusters

As an aside your code may be written as:

    LocalDate today = LocalDate.now(ZoneId.of("America/Tortola"));
    LocalDate monday = today.with(TemporalAdjusters.nextOrSame(DayOfWeek.MONDAY));
    LocalDate tue = today.with(TemporalAdjusters.nextOrSame(DayOfWeek.TUESDAY));
    LocalDate wed = today.with(TemporalAdjusters.nextOrSame(DayOfWeek.WEDNESDAY));
    LocalDate thur = today.with(TemporalAdjusters.nextOrSame(DayOfWeek.THURSDAY));
    LocalDate fri = today.with(TemporalAdjusters.nextOrSame(DayOfWeek.FRIDAY));
    LocalDate sat = today.with(TemporalAdjusters.nextOrSame(DayOfWeek.SATURDAY));
    LocalDate sunday = today.with(TemporalAdjusters.nextOrSame(DayOfWeek.SUNDAY));

I have used the following imports:

import org.threeten.bp.DayOfWeek;
import org.threeten.bp.LocalDate;
import org.threeten.bp.ZoneId;
import org.threeten.bp.temporal.TemporalAdjusters;

Links

Java Specification Request (JSR) 310, where java.time was first described.
ThreeTen Backport project, the backport of java.time to Java 6 and 7 (ThreeTen for JSR-310).
ThreeTenABP, Android edition of ThreeTen Backport
Question: How to use ThreeTenABP in Android Project, with a very thorough explanation.
Comment about dependencies by Satyajit Tarafdar

回答3:

Thrown if the Java Virtual Machine or a ClassLoader instance tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found. The searched-for class definition existed when the currently executing class was compiled, but the definition can no longer be found.

来源：https://stackoverflow.com/questions/52510370/java-lang-noclassdeffounderror-failed-resolution-of-ljava-time-localdate-erro

标签

java

android

java-time