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| | * [[#What You May Need to Know About Weaving JPA Entities|What You May Need to Know About Weaving JPA Entities]] | | * [[#What You May Need to Know About Weaving JPA Entities|What You May Need to Know About Weaving JPA Entities]] |
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| − | <span id="Table 19-33"></span>
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| − | ''''' EclipseLink JPA Support for Lazy Loading by Mapping Type'''''
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| − | {| class="RuleFormalWideMax" dir="ltr" title="EclipseLink JPA Support for Lazy Loading by Mapping Type" summary="This table lists EclipseLink JPA mapping support for lazy loading by mapping type for Java EE (in container) and Java SE (outside of container) applications." width="100%" border="1" frame="border" rules="all" cellpadding="3" frame="border" rules="all"
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| − | |- align="left" valign="top"
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| − | ! id="r1c1-t52" align="left" valign="bottom" | '''Mapping'''
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| − | ! id="r1c2-t52" align="left" valign="bottom" | '''Java EE''' <sup> 1 </sup>
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| − | ! id="r1c3-t52" align="left" valign="bottom" | '''Java SE'''
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| − | |- align="left" valign="top"
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| − | | id="r2c1-t52" headers="r1c1-t52" align="left" |
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| − | Many-to_many
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| − | | headers="r2c1-t52 r1c2-t52" align="left" |
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| − | EclipseLink JPA performs lazy loading when the <tt>fetch</tt> attribute is set to <tt>javax.persistence.FetchType.LAZY</tt> (default).
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| − | | headers="r2c1-t52 r1c3-t52" align="left" |
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| − | EclipseLink JPA performs lazy loading when the <tt>fetch</tt> attribute is set to <tt>javax.persistence.FetchType.LAZY</tt> (default).
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| − |
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| − | |- align="left" valign="top"
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| − | | id="r3c1-t52" headers="r1c1-t52" align="left" |
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| − | One-to-many
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| − | | headers="r3c1-t52 r1c2-t52" align="left" |
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| − | EclipseLink JPA performs lazy loading when the <tt>fetch</tt> attribute is set to <tt>javax.persistence.FetchType.LAZY</tt> (default).
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| − | | headers="r3c1-t52 r1c3-t52" align="left" |
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| − | EclipseLink JPA performs lazy loading when the <tt>fetch</tt> attribute is set to <tt>javax.persistence.FetchType.LAZY</tt> (default).
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| − |
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| − | |- align="left" valign="top"
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| − | | id="r4c1-t52" headers="r1c1-t52" align="left" |
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| − | One-to-one
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| − | | headers="r4c1-t52 r1c2-t52" align="left" |
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| − | EclipseLink JPA performs lazy loading when the <tt>fetch</tt> attribute is set to <tt>javax.persistence.FetchType.LAZY</tt>.
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| − | | headers="r4c1-t52 r1c3-t52" align="left" |
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| − | By default, EclipseLink JPA ignores the <tt>fetch</tt> attribute and default javax.persistence.<tt>FetchType.EAGER</tt> applies.
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| − | <!--
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| − | To configure EclipseLink JPA to perform lazy loading when the <tt>fetch</tt> attribute set to <tt>FetchType.LAZY</tt>, consider one of the following:
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| − | * [[#How to Configure Dynamic Weaving for JPA Entities Using the EclipseLink Agent|How to Configure Dynamic Weaving for JPA Entities Using the EclipseLink Agent]]
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| − | * [[#How to Configure Static Weaving for JPA Entities|How to Configure Static Weaving for JPA Entities]]
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| − | -->
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| − |
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| − | |- align="left" valign="top"
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| − | | id="r5c1-t52" headers="r1c1-t52" align="left" |
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| − | Many-to-one
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| − | | headers="r5c1-t52 r1c2-t52" align="left" |
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| − | EclipseLink JPA performs lazy loading when the <tt>fetch</tt> attribute is set to <tt>javax.persistence.FetchType.LAZY</tt>.
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| − | | headers="r5c1-t52 r1c3-t52" align="left" |
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| − | By default, EclipseLink JPA ignores the <tt>fetch</tt> attribute and default <tt>javax.persistence.FetchType.EAGER</tt> applies.
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| − | <!--
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| − | To configure EclipseLink JPA to perform lazy loading when the <tt>fetch</tt> attribute set to <tt>FetchType.LAZY</tt>, configure one of the following:
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| − | * [[#How to Configure Dynamic Weaving for JPA Entities Using the EclipseLink Agent|How to Configure Dynamic Weaving for JPA Entities Using the EclipseLink Agent]]
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| − | * [[#How to Configure Static Weaving for JPA Entities|How to Configure Static Weaving for JPA Entities]]
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| − | -->
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| − |
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| − | |- align="left" valign="top"
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| − | | id="r6c1-t52" headers="r1c1-t52" align="left" |
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| − | Basic
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| − | | headers="r6c1-t52 r1c2-t52" align="left" |
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| − | EclipseLink JPA performs lazy loading when the <tt>fetch</tt> attribute is set to <tt>javax.persistence.FetchType.LAZY</tt>.
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| − | | headers="r6c1-t52 r1c2-t52" align="left" |
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| − | By default, EclipseLink JPA ignores the <tt>fetch</tt> attribute and default javax.persistence.<tt>FetchType.EAGER</tt> applies.
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| − | <!--
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| − | To configure EclipseLink JPA to perform lazy loading when the <tt>fetch</tt> attribute set to <tt>FetchType.LAZY</tt>, consider one of the following:
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| − | * [[#How to Configure Dynamic Weaving for JPA Entities Using the EclipseLink Agent|How to Configure Dynamic Weaving for JPA Entities Using the EclipseLink Agent]]
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| − | * [[#How to Configure Static Weaving for JPA Entities|How to Configure Static Weaving for JPA Entities]]
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| − | -->
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| − | |}
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| | | | |
| | {{EclipseLink_JPA | | {{EclipseLink_JPA |
JPA specifies that lazy loading is a hint to the persistence provider that data should be fetched lazily when it is first accessed, if possible.
If you are developing your application in a Java EE environment, you only have to set fetch to javax.persistence.FetchType.LAZY, and EclipseLink persistence provider will supply all the necessary functionality.
When using a one-to-one or many-to-one mapping in a Java SE environment, to configure EclipseLink JPA to perform lazy loading when the fetch attribute is set to FetchType.LAZY, configure either dynamic or static weaving.
When using a one-to-one or many-to-one mapping in a Java SE environment that does not permit the use of -javaagent on the JVM command line, to configure EclipseLink JPA to perform lazy loading when annotation attribute fetch is set to javax.persistence.FetchType.LAZY, you can use static weaving.
Key API
