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6*3ff81872SXin Li<TITLE>
7*3ff81872SXin LiProvider
8*3ff81872SXin Li</TITLE>
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10*3ff81872SXin Li<META NAME="keywords" CONTENT="javax.inject.Provider interface">
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13*3ff81872SXin Li
14*3ff81872SXin Li<SCRIPT type="text/javascript">
15*3ff81872SXin Lifunction windowTitle()
16*3ff81872SXin Li{
17*3ff81872SXin Li    parent.document.title="Provider";
18*3ff81872SXin Li}
19*3ff81872SXin Li</SCRIPT>
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84*3ff81872SXin Li<H2>
85*3ff81872SXin Li<FONT SIZE="-1">
86*3ff81872SXin Lijavax.inject</FONT>
87*3ff81872SXin Li<BR>
88*3ff81872SXin LiInterface Provider&lt;T&gt;</H2>
89*3ff81872SXin Li<HR>
90*3ff81872SXin Li<DL>
91*3ff81872SXin Li<DT><PRE>public interface <B>Provider&lt;T&gt;</B></DL>
92*3ff81872SXin Li</PRE>
93*3ff81872SXin Li
94*3ff81872SXin Li<P>
95*3ff81872SXin LiProvides instances of <code>T</code>. Typically implemented by an injector. For
96*3ff81872SXin Li any type <code>T</code> that can be injected, you can also inject
97*3ff81872SXin Li <code>Provider&lt;T&gt;</code>. Compared to injecting <code>T</code> directly, injecting
98*3ff81872SXin Li <code>Provider&lt;T&gt;</code> enables:
99*3ff81872SXin Li
100*3ff81872SXin Li <ul>
101*3ff81872SXin Li   <li>retrieving multiple instances.</li>
102*3ff81872SXin Li   <li>lazy or optional retrieval of an instance.</li>
103*3ff81872SXin Li   <li>breaking circular dependencies.</li>
104*3ff81872SXin Li   <li>abstracting scope so you can look up an instance in a smaller scope
105*3ff81872SXin Li      from an instance in a containing scope.</li>
106*3ff81872SXin Li </ul>
107*3ff81872SXin Li
108*3ff81872SXin Li <p>For example:
109*3ff81872SXin Li
110*3ff81872SXin Li <pre>
111*3ff81872SXin Li   class Car {
112*3ff81872SXin Li     &#064;Inject Car(Provider&lt;Seat> seatProvider) {
113*3ff81872SXin Li       Seat driver = seatProvider.get();
114*3ff81872SXin Li       Seat passenger = seatProvider.get();
115*3ff81872SXin Li       ...
116*3ff81872SXin Li     }
117*3ff81872SXin Li   }</pre>
118*3ff81872SXin Li<P>
119*3ff81872SXin Li
120*3ff81872SXin Li<P>
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122*3ff81872SXin Li
123*3ff81872SXin Li<P>
124*3ff81872SXin Li
125*3ff81872SXin Li<!-- ========== METHOD SUMMARY =========== -->
126*3ff81872SXin Li
127*3ff81872SXin Li<A NAME="method_summary"><!-- --></A>
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130*3ff81872SXin Li<TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2">
131*3ff81872SXin Li<B>Method Summary</B></FONT></TH>
132*3ff81872SXin Li</TR>
133*3ff81872SXin Li<TR BGCOLOR="white" CLASS="TableRowColor">
134*3ff81872SXin Li<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
135*3ff81872SXin Li<CODE>&nbsp;<A HREF="../../javax/inject/Provider.html" title="type parameter in Provider">T</A></CODE></FONT></TD>
136*3ff81872SXin Li<TD><CODE><B><A HREF="../../javax/inject/Provider.html#get()">get</A></B>()</CODE>
137*3ff81872SXin Li
138*3ff81872SXin Li<BR>
139*3ff81872SXin Li&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Provides a fully-constructed and injected instance of <code>T</code>.</TD>
140*3ff81872SXin Li</TR>
141*3ff81872SXin Li</TABLE>
142*3ff81872SXin Li&nbsp;
143*3ff81872SXin Li<P>
144*3ff81872SXin Li
145*3ff81872SXin Li<!-- ============ METHOD DETAIL ========== -->
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150*3ff81872SXin Li<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
151*3ff81872SXin Li<B>Method Detail</B></FONT></TH>
152*3ff81872SXin Li</TR>
153*3ff81872SXin Li</TABLE>
154*3ff81872SXin Li
155*3ff81872SXin Li<A NAME="get()"><!-- --></A><H3>
156*3ff81872SXin Liget</H3>
157*3ff81872SXin Li<PRE>
158*3ff81872SXin Li<A HREF="../../javax/inject/Provider.html" title="type parameter in Provider">T</A> <B>get</B>()</PRE>
159*3ff81872SXin Li<DL>
160*3ff81872SXin Li<DD>Provides a fully-constructed and injected instance of <code>T</code>.
161*3ff81872SXin Li<P>
162*3ff81872SXin Li<DD><DL>
163*3ff81872SXin Li
164*3ff81872SXin Li<DT><B>Throws:</B>
165*3ff81872SXin Li<DD><CODE>java.lang.RuntimeException</CODE> - if the injector encounters an error while
166*3ff81872SXin Li  providing an instance. For example, if an injectable member on
167*3ff81872SXin Li  <code>T</code> throws an exception, the injector may wrap the exception
168*3ff81872SXin Li  and throw it to the caller of <code>get()</code>. Callers should not try
169*3ff81872SXin Li  to handle such exceptions as the behavior may vary across injector
170*3ff81872SXin Li  implementations and even different configurations of the same injector.</DL>
171*3ff81872SXin Li</DD>
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