java.lang.NoClassDefFoundError：解析失败：Ljava/time/LocalDate； 错误

Question

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...

Answer 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 .

Answer 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

Answer 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.

Answer 4

Use SimpleDateFormat and Calendar. You may also need different implementations for pre and post sdk 26

    private String getCurrentDateTime() {
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            Log.d(TAG, "getCurrentDateTime: greater than O");
            return LocalDateTime.now().format(DateTimeFormatter.ofPattern("h:m a"));
        } else{
            Log.d(TAG, "getCurrentDateTime: less than O");
            SimpleDateFormat SDFormat = new SimpleDateFormat("h:m a");
            return SDFormat.format(new Date());
        }
}