org.eclipse.equinox.p2.query

Class QueryUtil

java.lang.Object

org.eclipse.equinox.p2.query.QueryUtil

public class QueryUtil
extends java.lang.Object

Helper class for query related tasks.

Since:

2.0

Field Summary

Fields

Modifier and Type	Field and Description
static IQuery<IInstallableUnit>	ALL_UNITS
static java.lang.String	ANY
static IQuery<IInstallableUnit>	NO_UNITS
static java.lang.String	PROP_TYPE_CATEGORY
static java.lang.String	PROP_TYPE_GROUP
static java.lang.String	PROP_TYPE_PATCH

Constructor Summary

Constructors

Constructor and Description
QueryUtil()

Method Summary

Modifier and Type	Method and Description
static <T> IQueryable<T>	compoundQueryable(java.util.Collection<? extends IQueryable<T>> queryables) Creates a queryable that combines the given collection of input queryables
static <T> IQueryable<T>	compoundQueryable(IQueryable<T> query1, IQueryable<T> query2) Creates a queryable that combines the two provided input queryables
static <T> IQuery<T>	createCompoundQuery(java.util.Collection<? extends IQuery<? extends T>> queries, boolean and) Creates a compound query that combines the given queries.
static <T> IQuery<T>	createCompoundQuery(IQuery<? extends T> query1, IQuery<T> query2, boolean and) Creates a compound query that combines the two queries.
static IQuery<IInstallableUnit>	createIUAnyQuery() Returns a query that matches all InstallableUnit elements
static IQuery<IInstallableUnit>	createIUCategoryMemberQuery(IInstallableUnit category) Creates a new query that will return the members of the given category.
static IQuery<IInstallableUnit>	createIUCategoryQuery() Creates a query matching every IInstallableUnit that is a category.
static IQuery<IInstallableUnit>	createIUGroupQuery() Creates a query matching every IInstallableUnit that is a group.
static IQuery<IInstallableUnit>	createIUPatchQuery() Creates an IInstallableUnit that will match all patches.
static IQuery<IInstallableUnit>	createIUProductQuery() Creates an IInstallableUnit that will match all products.
static IQuery<IInstallableUnit>	createIUPropertyQuery(java.lang.String propertyName, java.lang.String propertyValue) Creates a query that searches for IInstallableUnit instances that have a property whose value matches the provided value.
static IQuery<IInstallableUnit>	createIUQuery(IVersionedId versionedId) Creates a query that will match any IInstallableUnit with the given id and version.
static IQuery<IInstallableUnit>	createIUQuery(java.lang.String id) Creates a query that will match any IInstallableUnit with the given id, regardless of version.
static IQuery<IInstallableUnit>	createIUQuery(java.lang.String id, Version version) Creates a query that will match any IInstallableUnit with the given id and version.
static IQuery<IInstallableUnit>	createIUQuery(java.lang.String id, VersionRange range) Creates a query that will match any IInstallableUnit with the given id, and whose version falls in the provided range.
static IQuery<IInstallableUnit>	createLatestIUQuery() Creates a query that returns the latest version for each unique id of an IVersionedId.
static <T extends IVersionedId> IQuery<T>	createLatestQuery(IQuery<T> query) Creates a query that returns the latest version for each unique id of an IVersionedId from the collection produced by query.
static <T> IQuery<T>	createLimitQuery(IQuery<T> query, int limit) Creates a limit query that can be used to limit the number of query results returned.
static <T> IQuery<T>	createMatchQuery(java.lang.Class<? extends T> matchingClass, IExpression matchExpression, java.lang.Object... parameters) Creates an query that will iterate over all candidates and discriminate all candidates that are not instances of matchingClass or for which the boolean matchExpression returns false.
static <T> IQuery<T>	createMatchQuery(java.lang.Class<? extends T> matchingClass, java.lang.String matchExpression, java.lang.Object... parameters) Parses the matchExpression and creates an query that will iterate over all candidates and discriminate all candidates that are not instances of matchingClass or for which the boolean matchExpression returns false.
static IQuery<IInstallableUnit>	createMatchQuery(IExpression matchExpression, java.lang.Object... parameters) Creates an IInstallableUnit query that will iterate over all candidates and discriminate by applying the boolean matchExpression on each candidate.
static IQuery<IInstallableUnit>	createMatchQuery(java.lang.String matchExpression, java.lang.Object... parameters) Parses the matchExpression and creates an IInstallableUnit query that will iterate over all candidates and discriminate by applying the boolean matchExpression on each candidate.
static <T> IQuery<T>	createPipeQuery(java.util.Collection<? extends IQuery<? extends T>> queries) Creates a piped query based on the provided input queries.
static <T> IQuery<T>	createPipeQuery(IQuery<? extends T> query1, IQuery<? extends T> query2) Creates a piped query based on the provided input queries.
static <T> IQuery<T>	createQuery(java.lang.Class<? extends T> matchingClass, IExpression expression, java.lang.Object... parameters) Creates a query that will limit the result to instances of the matchingClass.
static <T> IQuery<T>	createQuery(java.lang.Class<? extends T> matchingClass, java.lang.String expression, java.lang.Object... parameters) Parses the expression and creates a query that will limit the result to instances of the matchingClass.
static IQuery<IInstallableUnit>	createQuery(IExpression expression, java.lang.Object... parameters) Creates an IInstallableUnit query based on an expression that uses all candidates as input.
static IQuery<IInstallableUnit>	createQuery(java.lang.String expression, java.lang.Object... parameters) Parses the expression and creates an IInstallableUnit query.
static boolean	isCategory(IInstallableUnit iu) Test if the IInstallableUnit is a category.
static boolean	isFragment(IInstallableUnit iu) Test if the IInstallableUnit is a fragment.
static boolean	isGroup(IInstallableUnit iu) Test if the IInstallableUnit is a group.
static boolean	isPatch(IInstallableUnit iu) Test if the IInstallableUnit is a patch.
static boolean	isProduct(IInstallableUnit iu) Test if the IInstallableUnit is a product.

Methods inherited from class java.lang.Object

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

Field Detail

ALL_UNITS

public static final IQuery<IInstallableUnit> ALL_UNITS

ANY

public static final java.lang.String ANY

See Also:

Constant Field Values

NO_UNITS

public static final IQuery<IInstallableUnit> NO_UNITS

PROP_TYPE_CATEGORY

public static final java.lang.String PROP_TYPE_CATEGORY

See Also:

Constant Field Values

PROP_TYPE_GROUP

public static final java.lang.String PROP_TYPE_GROUP

See Also:

Constant Field Values

PROP_TYPE_PATCH

public static final java.lang.String PROP_TYPE_PATCH

See Also:

Constant Field Values

Constructor Detail

QueryUtil

public QueryUtil()

Method Detail

compoundQueryable

public static <T> IQueryable<T> compoundQueryable(java.util.Collection<? extends IQueryable<T>> queryables)

Creates a queryable that combines the given collection of input queryables

Parameters:

queryables - The collection of queryables to be combined

compoundQueryable

public static <T> IQueryable<T> compoundQueryable(IQueryable<T> query1,
                                                  IQueryable<T> query2)

Creates a queryable that combines the two provided input queryables

Parameters:

query1 - The first queryable

query2 - The second queryable

createCompoundQuery

public static <T> IQuery<T> createCompoundQuery(java.util.Collection<? extends IQuery<? extends T>> queries,
                                                boolean and)

Creates a compound query that combines the given queries. If all queries are candidate match queries, then the queries will be concatenated as a boolean 'and' or a boolean 'or' expression depending on the and flag. If at least one query is a full query, all queries will instead be evaluated using intersection when and is true or a union.

Parameters:

queries - The queries to perform

and - true if this query represents an intersection or a logical 'and', and false if this query represents a union or a logical 'or'.

Returns:

A compound query

createCompoundQuery

public static <T> IQuery<T> createCompoundQuery(IQuery<? extends T> query1,
                                                IQuery<T> query2,
                                                boolean and)

Creates a compound query that combines the two queries. If both queries are candidate match queries, then the queries will be concatenated as a boolean 'and' or a boolean 'or' expression depending on the and flag. If at least one query is a full query, all queries will instead be evaluated using intersection when and is true or a union.

Parameters:

query1 - the first query

query2 - the second query

and - true if this query represents an intersection or a logical 'and', and false if this query represents a union or a logical 'or'.

Returns:

A compound query

createIUAnyQuery

public static IQuery<IInstallableUnit> createIUAnyQuery()

Returns a query that matches all InstallableUnit elements

createIUCategoryMemberQuery

public static IQuery<IInstallableUnit> createIUCategoryMemberQuery(IInstallableUnit category)

Creates a new query that will return the members of the given category. If the specified IInstallableUnit is not a category, then no installable unit will satisfy the query.

Parameters:

category - The category

Returns:

A query that returns category members

createIUCategoryQuery

public static IQuery<IInstallableUnit> createIUCategoryQuery()

Creates a query matching every IInstallableUnit that is a category.

Returns:

The query that matches categories

Since:

2.0

createIUGroupQuery

public static IQuery<IInstallableUnit> createIUGroupQuery()

Creates a query matching every IInstallableUnit that is a group.

Returns:

a query that matches all groups

createIUPatchQuery

public static IQuery<IInstallableUnit> createIUPatchQuery()

Creates an IInstallableUnit that will match all patches.

Returns:

The created query

createIUProductQuery

public static IQuery<IInstallableUnit> createIUProductQuery()

Creates an IInstallableUnit that will match all products.

Returns:

The created query

Since:

2.2

createIUPropertyQuery

public static IQuery<IInstallableUnit> createIUPropertyQuery(java.lang.String propertyName,
                                                             java.lang.String propertyValue)

Creates a query that searches for IInstallableUnit instances that have a property whose value matches the provided value. If no property name is specified, then all IInstallableUnit instances are accepted.

Parameters:

propertyName - The key of the property to match or null to match all

propertyValue - The value of the property. Can be ANY to match all values except null

Returns:

The query matching properties

createIUQuery

public static IQuery<IInstallableUnit> createIUQuery(IVersionedId versionedId)

Creates a query that will match any IInstallableUnit with the given id and version.

Parameters:

versionedId - The precise id/version combination that a matching unit must have

Returns:

a query that matches IU's by id and version

createIUQuery

public static IQuery<IInstallableUnit> createIUQuery(java.lang.String id)

Creates a query that will match any IInstallableUnit with the given id, regardless of version.

Parameters:

id - The installable unit id to match, or null to match any id

Returns:

a query that matches IU's by id

createIUQuery

public static IQuery<IInstallableUnit> createIUQuery(java.lang.String id,
                                                     Version version)

Creates a query that will match any IInstallableUnit with the given id and version.

Parameters:

id - The installable unit id to match, or null to match any id

version - The precise version that a matching unit must have or null to match any version

Returns:

a query that matches IU's by id and version

createIUQuery

public static IQuery<IInstallableUnit> createIUQuery(java.lang.String id,
                                                     VersionRange range)

Creates a query that will match any IInstallableUnit with the given id, and whose version falls in the provided range.

Parameters:

id - The installable unit id to match, or null to match any id

range - The version range to match or null to match any range.

Returns:

a query that matches IU's by id and range

createLatestIUQuery

public static IQuery<IInstallableUnit> createLatestIUQuery()

Creates a query that returns the latest version for each unique id of an IVersionedId. All other elements are discarded.

Returns:

A query matching the latest version for each id.

createLatestQuery

public static <T extends IVersionedId> IQuery<T> createLatestQuery(IQuery<T> query)

Creates a query that returns the latest version for each unique id of an IVersionedId from the collection produced by query. All other elements are discarded.

Parameters:

query - The query that precedes the latest query when evaluating.

Returns:

A query matching the latest version for each id.

createLimitQuery

public static <T> IQuery<T> createLimitQuery(IQuery<T> query,
                                             int limit)

Creates a limit query that can be used to limit the number of query results returned. Once the limit is reached, the query is terminated.

Parameters:

query - The query that should be limited

limit - A positive integer denoting the limit

Returns:

A limited query

Since:

2.0

createMatchQuery

public static IQuery<IInstallableUnit> createMatchQuery(IExpression matchExpression,
                                                        java.lang.Object... parameters)

Creates an IInstallableUnit query that will iterate over all candidates and discriminate by applying the boolean matchExpression on each candidate.

Parameters:

matchExpression - The boolean expression used for filtering one candidate

parameters - Values for parameter substitution

Returns:

The created query

createMatchQuery

public static IQuery<IInstallableUnit> createMatchQuery(java.lang.String matchExpression,
                                                        java.lang.Object... parameters)

Parses the matchExpression and creates an IInstallableUnit query that will iterate over all candidates and discriminate by applying the boolean matchExpression on each candidate.

Parameters:

matchExpression - The boolean expression used for filtering one candidate

parameters - Values for parameter substitution

Returns:

The created query

createMatchQuery

public static <T> IQuery<T> createMatchQuery(java.lang.Class<? extends T> matchingClass,
                                             IExpression matchExpression,
                                             java.lang.Object... parameters)

Creates an query that will iterate over all candidates and discriminate all candidates that are not instances of matchingClass or for which the boolean matchExpression returns false.

Parameters:

matchingClass - The class that matching candidates must be an instance of

matchExpression - The boolean expression used for filtering one candidate

parameters - Values for parameter substitution

Returns:

The created query

createMatchQuery

public static <T> IQuery<T> createMatchQuery(java.lang.Class<? extends T> matchingClass,
                                             java.lang.String matchExpression,
                                             java.lang.Object... parameters)

Parses the matchExpression and creates an query that will iterate over all candidates and discriminate all candidates that are not instances of matchingClass or for which the boolean matchExpression returns false.

Type Parameters:

T - The type of input object that the created query accepts

Parameters:

matchingClass - The class that matching candidates must be an instance of

matchExpression - The boolean expression used for filtering one candidate

parameters - Values for parameter substitution

Returns:

The created query

createPipeQuery

public static <T> IQuery<T> createPipeQuery(java.util.Collection<? extends IQuery<? extends T>> queries)

Creates a piped query based on the provided input queries.

A pipe is a composite query in which each sub-query is executed in succession. The results from the ith sub-query are piped as input into the i+1th sub-query. The query will short-circuit if any query returns an empty result set.

Parameters:

queries - the ordered list of queries to perform

Returns:

A query pipe

createPipeQuery

public static <T> IQuery<T> createPipeQuery(IQuery<? extends T> query1,
                                            IQuery<? extends T> query2)

Creates a piped query based on the provided input queries.

A pipe is a composite query in which each sub-query is executed in succession. The results from the ith sub-query are piped as input into the i+1th sub-query. The query will short-circuit if any query returns an empty result set.

Parameters:

query1 - the first query

query2 - the second query

Returns:

A query pipe

createQuery

public static IQuery<IInstallableUnit> createQuery(IExpression expression,
                                                   java.lang.Object... parameters)

Creates an IInstallableUnit query based on an expression that uses all candidates as input.

Parameters:

expression - The query expression

parameters - Values for parameter substitution

Returns:

The created query

createQuery

public static IQuery<IInstallableUnit> createQuery(java.lang.String expression,
                                                   java.lang.Object... parameters)

Parses the expression and creates an IInstallableUnit query. The expression is expected to use all candidates as input.

Parameters:

expression - The query expression

parameters - Values for parameter substitution

Returns:

The created query

createQuery

public static <T> IQuery<T> createQuery(java.lang.Class<? extends T> matchingClass,
                                        IExpression expression,
                                        java.lang.Object... parameters)

Creates a query that will limit the result to instances of the matchingClass. The expression is expected to use all candidates as input.

Parameters:

matchingClass - The class used as discriminator for the result

expression - The query expression

parameters - Values for parameter substitution

Returns:

The created query

createQuery

public static <T> IQuery<T> createQuery(java.lang.Class<? extends T> matchingClass,
                                        java.lang.String expression,
                                        java.lang.Object... parameters)

Parses the expression and creates a query that will limit the result to instances of the matchingClass. The expression is expected to use all candidates as input.

Parameters:

matchingClass - The class used as discriminator for the result

expression - The query expression

parameters - Values for parameter substitution

Returns:

The created query

isCategory

public static boolean isCategory(IInstallableUnit iu)

Test if the IInstallableUnit is a category.

Parameters:

iu - the element being tested.

Returns:

true if the parameter is a category.

isFragment

public static boolean isFragment(IInstallableUnit iu)

Test if the IInstallableUnit is a fragment.

Parameters:

iu - the element being tested.

Returns:

true if the parameter is a fragment.

isGroup

public static boolean isGroup(IInstallableUnit iu)

Test if the IInstallableUnit is a group.

Parameters:

iu - the element being tested.

Returns:

true if the parameter is a group.

isProduct

public static boolean isProduct(IInstallableUnit iu)

Test if the IInstallableUnit is a product.

Parameters:

iu - the element being tested.

Returns:

true if the parameter is a group.

Since:

2.2

isPatch

public static boolean isPatch(IInstallableUnit iu)

Test if the IInstallableUnit is a patch.

Parameters:

iu - the element being tested.

Returns:

true if the parameter is a patch.