Recipe Name:
Migrate return type to java.time
Description:
Migrate return type to java.time
Level:
warning
Language:
- java
- kotlin
Tags:
- java.time
- java.util.Calendar
- quality
Documentation
Migrate from java.util.Date and java.util.Calendar to Java Time
Prior to the Java SE 8 release, the Java date and time mechanism was provided by the java.util.Date, java.util.Calendar, and java.util.TimeZone classes, as well as their subclasses, such as java.util.GregorianCalendar.
These classes had several drawbacks, including:
- The Calendar class was not type safe.
- Because the classes were mutable, they could not be used in multithreaded applications.
- Bugs in application code were common due to the unusual numbering of months and the lack of type safety.
Perhaps you have legacy code that uses the java.util date and time classes and you would like to take advantage of the java.time functionality with minimal changes to your code.
Examples
Before
Calendar calendar = new GregorianCalendar(2020, 05, 10, 10, 30);
calendar.add(Calendar.YEAR, 1);
After
LocalDateTime calendar = LocalDateTime.of(2020, 05, 10, 10, 30);
calendar.plusYears(1);
References
Recipe
id: scw:calendar:return-type
version: 10
metadata:
name: Migrate return type to java.time
shortDescription: Migrate return type to java.time
level: warning
language: java; kotlin
enabled: true
descriptionFile: Java/Date-Calendar/descriptions/date-calendar.html
tags: java.time;java.util.Calendar;quality
search:
method:
returnType: java.util.Calendar
availableFixes:
- name: Migrate method return type to java.time.LocalDate
actions:
- changeType:
type: java.time.LocalDate
- name: Migrate method return type to java.time.LocalDateTime
actions:
- changeType:
type: java.time.LocalDateTime
- name: Migrate method return type to java.time.ZonedDateTime
actions:
- changeType:
type: java.time.ZonedDateTime
- name: Use OffsetDateTime
actions:
- changeType:
type: java.time.OffsetDateTime