org.opencms.file.collectors

类 CmsDateResourceComparator

java.lang.Object

org.opencms.file.collectors.CmsDateResourceComparator

所有已实现的接口:

java.util.Comparator<CmsResource>

public class CmsDateResourceComparator
extends java.lang.Object
implements java.util.Comparator<CmsResource>

Comparator for sorting resource objects based on dates.

The comparator can be configured to use any date based on resource attributes or properties. The user must in the constructor CmsDateResourceComparator(CmsObject, List, boolean) provide a list of one or more date identifiers that should be checked, in the order they should be checked. This list of dates identifiers must be Strings which tell the comparator which dates to use. The first valid date identifier that is found for a resource is used as date for comparing this resource to other resources.

The following date identifiers can be used to access the corresponding value of a CmsResource:

• "dateCreated", which means CmsResource#getDateCreated().
• "dateLastModified", which means CmsResource#getDateLastModified().
• "dateContent", which means CmsResource#getDateContent().
• "dateReleased", which means CmsResource#getDateReleased().
• "dateExpired", which means CmsResource#getDateExpired().
• Anything else will be treated as property name, so it will be attempted to read a property with that name from the resource, and convert that value to a long. Should this fail for any reason, the next entry from the list of dates will be processed.

• If no match is found at all, CmsResource#getDateCreated() is used as default.

Serves as Comparator for resources and as comparator key for the resource at the same time. Uses lazy initializing of comparator keys for a resource.

从以下版本开始:

6.0.0

字段概要

字段

限定符和类型	字段和说明
static java.util.List<java.lang.String>	DATE_ATTRIBUTES_LIST Possible keywords to read dates from the resource attributes in a List.

构造器概要

构造器

构造器和说明
CmsDateResourceComparator(CmsObject cms, java.util.List<java.lang.String> dateIdentifiers, boolean asc) Creates a new instance of this comparator key.

方法概要

方法

限定符和类型	方法和说明
static long	calculateDate(CmsObject cms, CmsResource resource, java.util.List<java.lang.String> dateIdentifiers, long defaultValue) Calculates the date to use for comparison of this resource based on the given date identifiers.
int	compare(CmsResource res0, CmsResource res1)
long	getDate() Returns the date of this resource comparator key.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

从接口继承的方法 java.util.Comparator

equals

字段详细资料

DATE_ATTRIBUTES_LIST

public static final java.util.List<java.lang.String> DATE_ATTRIBUTES_LIST

Possible keywords to read dates from the resource attributes in a List.

构造器详细资料

CmsDateResourceComparator

public CmsDateResourceComparator(CmsObject cms,
                         java.util.List<java.lang.String> dateIdentifiers,
                         boolean asc)

Creates a new instance of this comparator key.

参数:

cms - the current OpenCms user context

dateIdentifiers - the names of the dates to check

asc - if true, the date sort order is ascending, otherwise descending

方法详细资料

calculateDate

public static long calculateDate(CmsObject cms,
                 CmsResource resource,
                 java.util.List<java.lang.String> dateIdentifiers,
                 long defaultValue)

Calculates the date to use for comparison of this resource based on the given date identifiers.

参数:

cms - the current OpenCms user context

resource - the resource to create the key for

dateIdentifiers - the date identifiers to use for selecting the date

defaultValue - the default value to use in case no value can be calculated

返回:

the calculated date

另请参阅:

for a description about how the date identifieres are used

compare

public int compare(CmsResource res0,
          CmsResource res1)

指定者:

compare 在接口中 java.util.Comparator<CmsResource>

另请参阅:

Comparator.compare(java.lang.Object, java.lang.Object)

getDate

public long getDate()

Returns the date of this resource comparator key.

返回:

the date of this resource comparator key