Java Common Constants, Enums, and Utilities

Contents

1. 1. Java
   1. 1.1. Constants
   2. 1.2. Enum
   3. 1.3. Utilities
2. 2. Spring Framework
   1. 2.1. Constants
   2. 2.2. Enum
   3. 2.3. Utilities
3. 3. References

Java

Constants

java.lang.Math

• E
• PI

java.net.HttpURLConnection

• HTTP_OK
• HTTP_NO_CONTENT
• HTTP_BAD_REQUEST
• HTTP_UNAUTHORIZED
• HTTP_FORBIDDEN
• HTTP_NOT_FOUND
• HTTP_BAD_METHOD
• HTTP_INTERNAL_ERROR

javax.management.timer.Timer

• ONE_DAY
• ONE_HOUR
• ONE_MINUTE
• ONE_SECOND
• ONE_WEEK

Enum

java.nio.charset.StandardCharsets

• ISO_8859_1
• UTF_8.toString()

Utilities

java.util

• Arrays
  • asList(T… a)
  • sort(int[] a)
  • toString(Object[] a)
• Collections
  • emptyList()
  • emptyMap()
  • emptySet()
  • sort(List list)
  • sort(List list, Comparator<? super T> c)
• Objects
  • nonNull()
  • isNull(Object obj)
  • equals(Object a, Object b)
  • deepEquals(Object a, Object b)
  • compare(T a, T b, Comparator<? super T> c)
  • requireNonNull(T obj, String message)
  • toString(Object o, String nullDefault)
• UUID
  • randomUUID()

Others

• Optional
• Random
• StringJoiner

Spring Framework

Constants

org.springframework.http.HttpHeaders

• ACCEPT_LANGUAGE
• AUTHORIZATION
• CACHE_CONTROL
• CONTENT_DISPOSITION
• CONTENT_TYPE
• USER_AGENT

org.springframework.http.MediaType

• APPLICATION_JSON_VALUE
• APPLICATION_FORM_URLENCODED_VALUE
• MULTIPART_FORM_DATA_VALUE

Enum

org.springframework.http.HttpMethod

• GET.toString()
• POST
• PUT
• DELETE

org.springframework.http.HttpStatus

• OK
• NO_CONTENT
• BAD_REQUEST
• UNAUTHORIZED
• FORBIDDEN
• NOT_FOUND
• METHOD_NOT_ALLOWED
• INTERNAL_SERVER_ERROR

Utilities

org.springframework.util

• StringUtils
  • hasLength(String str)
• CollectionUtils
  • isEmpty(Collection<?> collection)
• ClassUtils

org.springframework.beans

• BeanUtils
  • copyProperties(Object source, Object target)

References

[1] Spring Framework Constant Field Values

[2] Java 8 Constant Field Values