Class Request

java.lang.Object
com.onwbp.adaptation.Request

public final class Request extends Object
Defines a specific request on a table.

A request is executed by calling the method execute().

Multi-threading

Note that this class is not synchronized.

Performance

See Setting a fetch size on optimization with respect to the expected size of the RequestResult and the limitations when using PostgreSQL as the underlying database.

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  • Method Details

    • isIncludeOcculting

      public boolean isIncludeOcculting()
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    • setIncludeOcculting

      public void setIncludeOcculting(boolean includeOcculting)
      Sets whether or not the request must consider records in occulting mode.

      By default, these records are ignored.

    • getLocale

      public Locale getLocale()
      Since:
      5.5.0
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    • setLocale

      public void setLocale(Locale aLocale)
      Sets a locale to the request. It may be needed if the request filter is locale-dependent, i.e. a predicate filter of the form osd:label(./localized_field)='A'.
      Since:
      5.5.0
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    • setSession

      public void setSession(Session aSession)
      Sets the user session on the request. This activates the permission checks and sets the session locale.

      Applying the permissions checks will have the following effects:

      • the returned records will be filtered using the access rules on records if any;
      • a QueryPermissionException will be thrown on execution if at least one forbidden node is used in the request. Currently, this does not take into account record-dependent access rules set on fields.
      Since:
      5.5.0
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    • getSortCriteria

      public RequestSortCriteria getSortCriteria()
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    • setOrderByPrimaryKey

      public void setOrderByPrimaryKey()
      Specifies that the request result will be sorted by primary key in ascending order.
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    • setSortCriteria

      public void setSortCriteria(RequestSortCriteria aSortCriteria)
      Specifies that the request result will be sorted according to the specified criteria.

      If this method is not called, the result will be ordered according to the primary key fields (ascending). If this method is called with a null sort criteria, the result will not be sorted in any particular order.

      Throws:
      IllegalArgumentException - if the specified sort is not consistent with the table structure.
      See Also:
    • sortByRelevancy

      public void sortByRelevancy()
      Specifies that the results of this request will be sorted according to their relevancy regarding the search criterion (most relevant first). This notion only makes sense for requests including a filter with text search. Requests which do not fulfill this condition will throw an error on execute() if they have specified this sort by relevancy. It is currently not possible to combine this special sort with additional sort criteria: this call will replace any pre-existing sort criteria.
      Since:
      6.0.0
    • isSortedByRelevancy

      public boolean isSortedByRelevancy()
      Returns whether the results of this request should be sorted by relevancy. Only requests including a filter with text search are likely to return true.
      Since:
      6.0.0
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    • getSpecificFilter

      public AdaptationFilter getSpecificFilter()
      Returns the current filter, if any. If an XPath filter has been specified, returns its programmatic version.
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    • setSpecificFilter

      public void setSpecificFilter(AdaptationFilter aFilter)
      Specifies that the request result will only include the records that satisfy the filter passed as an argument.

      If not set, the value of this property is null, and no specific filtering will be performed.

      If a filter has been specified by means of a method setXPathFilter, it is replaced by the specified filter.

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    • setXPathFilter

      public void setXPathFilter(String aPredicateExpression)
      Specifies that the request result will only include the records which satisfy the specified XPath predicate.

      This method is equivalent to:

       XPathFilter xpf = XPathFilter.newFilter(false, aPredicateExpression);
       this.setXPathFilter(xpf);
       

      Performance considerations: If the specified predicate must be often reused by multiple Request objects, it is recommended to use a cached filter. Parameterized expressions also help reuse.

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    • setXPathFilter

      public void setXPathFilter(XPathFilter anXPathFilter)
      Specifies that the request result will only include the records which satisfy the specified XPath filter.

      If a filter has been specified by means of the method setSpecificFilter(AdaptationFilter), it is replaced by the specified XPath filter.

      It is recommended to use the XPath filter when the predicate must be applied more than once, with different values. It allows using parameters and avoiding parsing the same predicate expression each time it is used.

      Since:
      5.7.0
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    • setXPathParameter

      public void setXPathParameter(String aParameterName, Object aParameterValue)
      For the current XPath filter, sets the value of the specified parameter.

      For example, if the current filter is the XPath predicate ./lastName=$myName, to set the parameter myName to 'Smith', the method must be invoked this way:

       aRequest.setXPathParameter("myName", "Smith");
       
      Parameters:
      aParameterName - name of the parameter
      aParameterValue - value of the parameter
      Throws:
      IllegalArgumentException - if one of the specified arguments is not defined or if the specified parameter name has basic inconsistencies.
      IllegalStateException - if no XPath filter has been specified.
      Since:
      5.7.0
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    • getFetchSize

      public int getFetchSize()
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    • setFetchSize

      public void setFetchSize(int rows)
      Provides a hint to the underlying database as to the number of records to fetch at a time from the result of executing this request. If the fetch size specified is '0', the underlying implementation determines the fetch size independently.
      Parameters:
      rows - the number of rows to fetch
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    • execute

      Executes the request and returns the result.

      Once this method has been called, it is mandatory to invoke the RequestResult.close() method on the returned object. Otherwise, this will fail to release some system resources.

      Throws:
      QueryPermissionException - if a session is provided and at least one forbidden node is used in the request.
      IncompatibleChangeError
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    • checkForbiddenNodes

      public Map<SchemaNode,Adaptation> checkForbiddenNodes()
      When the execution would fail and throw a QueryPermissionException, this method returns the forbidden fields and the dataset in which these are forbidden. Otherwise, returns an empty map.
      Since:
      6.0.0
    • paginate

      public RequestPagination paginate()
      Returns a new object to be used to paginate over the result of this request.
      Since:
      5.8.0
    • toString

      public String toString()
      Overrides:
      toString in class Object