1*3ff81872SXin Li<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2*3ff81872SXin Li<!--NewPage--> 3*3ff81872SXin Li<HTML> 4*3ff81872SXin Li<HEAD> 5*3ff81872SXin Li<!-- Generated by javadoc (build 1.5.0_16) on Mon Oct 12 16:11:19 PDT 2009 --> 6*3ff81872SXin Li<TITLE> 7*3ff81872SXin LiScope 8*3ff81872SXin Li</TITLE> 9*3ff81872SXin Li 10*3ff81872SXin Li<META NAME="keywords" CONTENT="javax.inject.Scope class"> 11*3ff81872SXin Li 12*3ff81872SXin Li<LINK REL ="stylesheet" TYPE="text/css" HREF="../../stylesheet.css" TITLE="Style"> 13*3ff81872SXin Li 14*3ff81872SXin Li<SCRIPT type="text/javascript"> 15*3ff81872SXin Lifunction windowTitle() 16*3ff81872SXin Li{ 17*3ff81872SXin Li parent.document.title="Scope"; 18*3ff81872SXin Li} 19*3ff81872SXin Li</SCRIPT> 20*3ff81872SXin Li<NOSCRIPT> 21*3ff81872SXin Li</NOSCRIPT> 22*3ff81872SXin Li 23*3ff81872SXin Li</HEAD> 24*3ff81872SXin Li 25*3ff81872SXin Li<BODY BGCOLOR="white" onload="windowTitle();"> 26*3ff81872SXin Li 27*3ff81872SXin Li 28*3ff81872SXin Li<!-- ========= START OF TOP NAVBAR ======= --> 29*3ff81872SXin Li<A NAME="navbar_top"><!-- --></A> 30*3ff81872SXin Li<A HREF="#skip-navbar_top" title="Skip navigation links"></A> 31*3ff81872SXin Li<TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""> 32*3ff81872SXin Li<TR> 33*3ff81872SXin Li<TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> 34*3ff81872SXin Li<A NAME="navbar_top_firstrow"><!-- --></A> 35*3ff81872SXin Li<TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> 36*3ff81872SXin Li <TR ALIGN="center" VALIGN="top"> 37*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../javax/inject/package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> 38*3ff81872SXin Li <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> 39*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> 40*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> 41*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> 42*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> 43*3ff81872SXin Li </TR> 44*3ff81872SXin Li</TABLE> 45*3ff81872SXin Li</TD> 46*3ff81872SXin Li<TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM> 47*3ff81872SXin Li</EM> 48*3ff81872SXin Li</TD> 49*3ff81872SXin Li</TR> 50*3ff81872SXin Li 51*3ff81872SXin Li<TR> 52*3ff81872SXin Li<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> 53*3ff81872SXin Li <A HREF="../../javax/inject/Qualifier.html" title="annotation in javax.inject"><B>PREV CLASS</B></A> 54*3ff81872SXin Li <A HREF="../../javax/inject/Singleton.html" title="annotation in javax.inject"><B>NEXT CLASS</B></A></FONT></TD> 55*3ff81872SXin Li<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> 56*3ff81872SXin Li <A HREF="../../index.html?javax/inject/Scope.html" target="_top"><B>FRAMES</B></A> 57*3ff81872SXin Li <A HREF="Scope.html" target="_top"><B>NO FRAMES</B></A> 58*3ff81872SXin Li <SCRIPT type="text/javascript"> 59*3ff81872SXin Li <!-- 60*3ff81872SXin Li if(window==top) { 61*3ff81872SXin Li document.writeln('<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>'); 62*3ff81872SXin Li } 63*3ff81872SXin Li //--> 64*3ff81872SXin Li</SCRIPT> 65*3ff81872SXin Li<NOSCRIPT> 66*3ff81872SXin Li <A HREF="../../allclasses-noframe.html"><B>All Classes</B></A> 67*3ff81872SXin Li</NOSCRIPT> 68*3ff81872SXin Li 69*3ff81872SXin Li 70*3ff81872SXin Li</FONT></TD> 71*3ff81872SXin Li</TR> 72*3ff81872SXin Li<TR> 73*3ff81872SXin Li<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> 74*3ff81872SXin Li SUMMARY: REQUIRED | OPTIONAL</FONT></TD> 75*3ff81872SXin Li<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> 76*3ff81872SXin LiDETAIL: ELEMENT</FONT></TD> 77*3ff81872SXin Li</TR> 78*3ff81872SXin Li</TABLE> 79*3ff81872SXin Li<A NAME="skip-navbar_top"></A> 80*3ff81872SXin Li<!-- ========= END OF TOP NAVBAR ========= --> 81*3ff81872SXin Li 82*3ff81872SXin Li<HR> 83*3ff81872SXin Li<!-- ======== START OF CLASS DATA ======== --> 84*3ff81872SXin Li<H2> 85*3ff81872SXin Li<FONT SIZE="-1"> 86*3ff81872SXin Lijavax.inject</FONT> 87*3ff81872SXin Li<BR> 88*3ff81872SXin LiAnnotation Type Scope</H2> 89*3ff81872SXin Li<HR> 90*3ff81872SXin Li<DL> 91*3ff81872SXin Li<DT><PRE><FONT SIZE="-1">@Target(value=ANNOTATION_TYPE) 92*3ff81872SXin Li@Retention(value=RUNTIME) 93*3ff81872SXin Li@Documented 94*3ff81872SXin Li</FONT>public @interface <B>Scope</B></DL> 95*3ff81872SXin Li</PRE> 96*3ff81872SXin Li 97*3ff81872SXin Li<P> 98*3ff81872SXin LiIdentifies scope annotations. A scope annotation applies to a class 99*3ff81872SXin Li containing an injectable constructor and governs how the injector reuses 100*3ff81872SXin Li instances of the type. By default, if no scope annotation is present, the 101*3ff81872SXin Li injector creates an instance (by injecting the type's constructor), uses 102*3ff81872SXin Li the instance for one injection, and then forgets it. If a scope annotation 103*3ff81872SXin Li is present, the injector may retain the instance for possible reuse in a 104*3ff81872SXin Li later injection. If multiple threads can access a scoped instance, its 105*3ff81872SXin Li implementation should be thread safe. The implementation of the scope 106*3ff81872SXin Li itself is left up to the injector. 107*3ff81872SXin Li 108*3ff81872SXin Li <p>In the following example, the scope annotation <code>@Singleton</code> ensures 109*3ff81872SXin Li that we only have one Log instance: 110*3ff81872SXin Li 111*3ff81872SXin Li <pre> 112*3ff81872SXin Li @Singleton 113*3ff81872SXin Li class Log { 114*3ff81872SXin Li void log(String message) { ... } 115*3ff81872SXin Li }</pre> 116*3ff81872SXin Li 117*3ff81872SXin Li <p>The injector generates an error if it encounters more than one scope 118*3ff81872SXin Li annotation on the same class or a scope annotation it doesn't support. 119*3ff81872SXin Li 120*3ff81872SXin Li <p>A scope annotation: 121*3ff81872SXin Li <ul> 122*3ff81872SXin Li <li>is annotated with <code>@Scope</code>, <code>@Retention(RUNTIME)</code>, 123*3ff81872SXin Li and typically <code>@Documented</code>.</li> 124*3ff81872SXin Li <li>should not have attributes.</li> 125*3ff81872SXin Li <li>is typically not <code>@Inherited</code>, so scoping is orthogonal to 126*3ff81872SXin Li implementation inheritance.</li> 127*3ff81872SXin Li <li>may have restricted usage if annotated with <code>@Target</code>. While 128*3ff81872SXin Li this specification covers applying scopes to classes only, some 129*3ff81872SXin Li injector configurations might use scope annotations 130*3ff81872SXin Li in other places (on factory method results for example).</li> 131*3ff81872SXin Li </ul> 132*3ff81872SXin Li 133*3ff81872SXin Li <p>For example: 134*3ff81872SXin Li 135*3ff81872SXin Li <pre> 136*3ff81872SXin Li @java.lang.annotation.Documented 137*3ff81872SXin Li @java.lang.annotation.Retention(RUNTIME) 138*3ff81872SXin Li @javax.inject.Scope 139*3ff81872SXin Li public @interface RequestScoped {}</pre> 140*3ff81872SXin Li 141*3ff81872SXin Li <p>Annotating scope annotations with <code>@Scope</code> helps the injector 142*3ff81872SXin Li detect the case where a programmer used the scope annotation on a class but 143*3ff81872SXin Li forgot to configure the scope in the injector. A conservative injector 144*3ff81872SXin Li would generate an error rather than not apply a scope. 145*3ff81872SXin Li<P> 146*3ff81872SXin Li 147*3ff81872SXin Li<P> 148*3ff81872SXin Li<DL> 149*3ff81872SXin Li<DT><B>See Also:</B><DD><A HREF="../../javax/inject/Singleton.html" title="annotation in javax.inject"><CODE>@Singleton</CODE></A></DL> 150*3ff81872SXin Li 151*3ff81872SXin Li<P> 152*3ff81872SXin Li 153*3ff81872SXin Li<P> 154*3ff81872SXin Li<!-- ========= END OF CLASS DATA ========= --> 155*3ff81872SXin Li<HR> 156*3ff81872SXin Li 157*3ff81872SXin Li 158*3ff81872SXin Li<!-- ======= START OF BOTTOM NAVBAR ====== --> 159*3ff81872SXin Li<A NAME="navbar_bottom"><!-- --></A> 160*3ff81872SXin Li<A HREF="#skip-navbar_bottom" title="Skip navigation links"></A> 161*3ff81872SXin Li<TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""> 162*3ff81872SXin Li<TR> 163*3ff81872SXin Li<TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> 164*3ff81872SXin Li<A NAME="navbar_bottom_firstrow"><!-- --></A> 165*3ff81872SXin Li<TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> 166*3ff81872SXin Li <TR ALIGN="center" VALIGN="top"> 167*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../javax/inject/package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> 168*3ff81872SXin Li <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> 169*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> 170*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> 171*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> 172*3ff81872SXin Li <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> 173*3ff81872SXin Li </TR> 174*3ff81872SXin Li</TABLE> 175*3ff81872SXin Li</TD> 176*3ff81872SXin Li<TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM> 177*3ff81872SXin Li</EM> 178*3ff81872SXin Li</TD> 179*3ff81872SXin Li</TR> 180*3ff81872SXin Li 181*3ff81872SXin Li<TR> 182*3ff81872SXin Li<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> 183*3ff81872SXin Li <A HREF="../../javax/inject/Qualifier.html" title="annotation in javax.inject"><B>PREV CLASS</B></A> 184*3ff81872SXin Li <A HREF="../../javax/inject/Singleton.html" title="annotation in javax.inject"><B>NEXT CLASS</B></A></FONT></TD> 185*3ff81872SXin Li<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> 186*3ff81872SXin Li <A HREF="../../index.html?javax/inject/Scope.html" target="_top"><B>FRAMES</B></A> 187*3ff81872SXin Li <A HREF="Scope.html" target="_top"><B>NO FRAMES</B></A> 188*3ff81872SXin Li <SCRIPT type="text/javascript"> 189*3ff81872SXin Li <!-- 190*3ff81872SXin Li if(window==top) { 191*3ff81872SXin Li document.writeln('<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>'); 192*3ff81872SXin Li } 193*3ff81872SXin Li //--> 194*3ff81872SXin Li</SCRIPT> 195*3ff81872SXin Li<NOSCRIPT> 196*3ff81872SXin Li <A HREF="../../allclasses-noframe.html"><B>All Classes</B></A> 197*3ff81872SXin Li</NOSCRIPT> 198*3ff81872SXin Li 199*3ff81872SXin Li 200*3ff81872SXin Li</FONT></TD> 201*3ff81872SXin Li</TR> 202*3ff81872SXin Li<TR> 203*3ff81872SXin Li<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> 204*3ff81872SXin Li SUMMARY: REQUIRED | OPTIONAL</FONT></TD> 205*3ff81872SXin Li<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> 206*3ff81872SXin LiDETAIL: ELEMENT</FONT></TD> 207*3ff81872SXin Li</TR> 208*3ff81872SXin Li</TABLE> 209*3ff81872SXin Li<A NAME="skip-navbar_bottom"></A> 210*3ff81872SXin Li<!-- ======== END OF BOTTOM NAVBAR ======= --> 211*3ff81872SXin Li 212*3ff81872SXin Li<HR> 213*3ff81872SXin Li<font size='-1'>Copyright (C) 2009 <a href='http://code.google.com/p/atinject/'>The JSR-330 Expert Group</a>. 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