<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<!--NewPage-->
<HTML>
<HEAD>
<!-- Generated by javadoc (build 1.5.0_16) on Mon Oct 12 16:11:19 PDT 2009 -->
<TITLE>
Scope
</TITLE>
<META NAME="keywords" CONTENT="javax.inject.Scope class">
<LINK REL ="stylesheet" TYPE="text/css" HREF="../../stylesheet.css" TITLE="Style">
<SCRIPT type="text/javascript">
function windowTitle()
{
parent.document.title="Scope";
}
</SCRIPT>
<NOSCRIPT>
</NOSCRIPT>
</HEAD>
<BODY BGCOLOR="white" onload="windowTitle();">
<!-- ========= START OF TOP NAVBAR ======= -->
<A NAME="navbar_top"><!-- --></A>
<A HREF="#skip-navbar_top" title="Skip navigation links"></A>
<TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY="">
<TR>
<TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1">
<A NAME="navbar_top_firstrow"><!-- --></A>
<TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY="">
<TR ALIGN="center" VALIGN="top">
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../javax/inject/package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD>
<TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD>
</TR>
</TABLE>
</TD>
<TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM>
</EM>
</TD>
</TR>
<TR>
<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
<A HREF="../../javax/inject/Qualifier.html" title="annotation in javax.inject"><B>PREV CLASS</B></A>
<A HREF="../../javax/inject/Singleton.html" title="annotation in javax.inject"><B>NEXT CLASS</B></A></FONT></TD>
<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
<A HREF="../../index.html?javax/inject/Scope.html" target="_top"><B>FRAMES</B></A>
<A HREF="Scope.html" target="_top"><B>NO FRAMES</B></A>
<SCRIPT type="text/javascript">
<!--
if(window==top) {
document.writeln('<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>');
}
//-->
</SCRIPT>
<NOSCRIPT>
<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>
</NOSCRIPT>
</FONT></TD>
</TR>
<TR>
<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
SUMMARY: REQUIRED | OPTIONAL</FONT></TD>
<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
DETAIL: ELEMENT</FONT></TD>
</TR>
</TABLE>
<A NAME="skip-navbar_top"></A>
<!-- ========= END OF TOP NAVBAR ========= -->
<HR>
<!-- ======== START OF CLASS DATA ======== -->
<H2>
<FONT SIZE="-1">
javax.inject</FONT>
<BR>
Annotation Type Scope</H2>
<HR>
<DL>
<DT><PRE><FONT SIZE="-1">@Target(value=ANNOTATION_TYPE)
@Retention(value=RUNTIME)
@Documented
</FONT>public @interface <B>Scope</B></DL>
</PRE>
<P>
Identifies scope annotations. A scope annotation applies to a class
containing an injectable constructor and governs how the injector reuses
instances of the type. By default, if no scope annotation is present, the
injector creates an instance (by injecting the type's constructor), uses
the instance for one injection, and then forgets it. If a scope annotation
is present, the injector may retain the instance for possible reuse in a
later injection. If multiple threads can access a scoped instance, its
implementation should be thread safe. The implementation of the scope
itself is left up to the injector.
<p>In the following example, the scope annotation <code>@Singleton</code> ensures
that we only have one Log instance:
<pre>
@Singleton
class Log {
void log(String message) { ... }
}</pre>
<p>The injector generates an error if it encounters more than one scope
annotation on the same class or a scope annotation it doesn't support.
<p>A scope annotation:
<ul>
<li>is annotated with <code>@Scope</code>, <code>@Retention(RUNTIME)</code>,
and typically <code>@Documented</code>.</li>
<li>should not have attributes.</li>
<li>is typically not <code>@Inherited</code>, so scoping is orthogonal to
implementation inheritance.</li>
<li>may have restricted usage if annotated with <code>@Target</code>. While
this specification covers applying scopes to classes only, some
injector configurations might use scope annotations
in other places (on factory method results for example).</li>
</ul>
<p>For example:
<pre>
@java.lang.annotation.Documented
@java.lang.annotation.Retention(RUNTIME)
@javax.inject.Scope
public @interface RequestScoped {}</pre>
<p>Annotating scope annotations with <code>@Scope</code> helps the injector
detect the case where a programmer used the scope annotation on a class but
forgot to configure the scope in the injector. A conservative injector
would generate an error rather than not apply a scope.
<P>
<P>
<DL>
<DT><B>See Also:</B><DD><A HREF="../../javax/inject/Singleton.html" title="annotation in javax.inject"><CODE>@Singleton</CODE></A></DL>
<P>
<P>
<!-- ========= END OF CLASS DATA ========= -->
<HR>
<!-- ======= START OF BOTTOM NAVBAR ====== -->
<A NAME="navbar_bottom"><!-- --></A>
<A HREF="#skip-navbar_bottom" title="Skip navigation links"></A>
<TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY="">
<TR>
<TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1">
<A NAME="navbar_bottom_firstrow"><!-- --></A>
<TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY="">
<TR ALIGN="center" VALIGN="top">
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../javax/inject/package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD>
<TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD>
</TR>
</TABLE>
</TD>
<TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM>
</EM>
</TD>
</TR>
<TR>
<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
<A HREF="../../javax/inject/Qualifier.html" title="annotation in javax.inject"><B>PREV CLASS</B></A>
<A HREF="../../javax/inject/Singleton.html" title="annotation in javax.inject"><B>NEXT CLASS</B></A></FONT></TD>
<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
<A HREF="../../index.html?javax/inject/Scope.html" target="_top"><B>FRAMES</B></A>
<A HREF="Scope.html" target="_top"><B>NO FRAMES</B></A>
<SCRIPT type="text/javascript">
<!--
if(window==top) {
document.writeln('<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>');
}
//-->
</SCRIPT>
<NOSCRIPT>
<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>
</NOSCRIPT>
</FONT></TD>
</TR>
<TR>
<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
SUMMARY: REQUIRED | OPTIONAL</FONT></TD>
<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
DETAIL: ELEMENT</FONT></TD>
</TR>
</TABLE>
<A NAME="skip-navbar_bottom"></A>
<!-- ======== END OF BOTTOM NAVBAR ======= -->
<HR>
<font size='-1'>Copyright (C) 2009 <a href='http://code.google.com/p/atinject/'>The JSR-330 Expert Group</a>. Licensed under the <a href='http://www.apache.org/licenses/LICENSE-2.0'>Apache License</a>, Version 2.0.</font>
</BODY>
</HTML>