gson-comments/gson/docs/javadocs/com/google/gson/ExclusionStrategy.html
2011-04-13 20:41:54 +00:00

306 lines
13 KiB
HTML

<!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 1.6.0_24) on Wed Apr 13 13:26:44 PDT 2011 -->
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<TITLE>
ExclusionStrategy (Gson 1.7.1 API)
</TITLE>
<META NAME="date" CONTENT="2011-04-13">
<LINK REL ="stylesheet" TYPE="text/css" HREF="../../../stylesheet.css" TITLE="Style">
<SCRIPT type="text/javascript">
function windowTitle()
{
if (location.href.indexOf('is-external=true') == -1) {
parent.document.title="ExclusionStrategy (Gson 1.7.1 API)";
}
}
</SCRIPT>
<NOSCRIPT>
</NOSCRIPT>
</HEAD>
<BODY BGCOLOR="white" onload="windowTitle();">
<HR>
<!-- ========= 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="../../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> &nbsp;<FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/ExclusionStrategy.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A>&nbsp;</TD>
</TR>
</TABLE>
</TD>
<TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM>
</EM>
</TD>
</TR>
<TR>
<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
&nbsp;PREV CLASS&nbsp;
&nbsp;<A HREF="../../../com/google/gson/FieldAttributes.html" title="class in com.google.gson"><B>NEXT CLASS</B></A></FONT></TD>
<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
<A HREF="../../../index.html?com/google/gson/ExclusionStrategy.html" target="_top"><B>FRAMES</B></A> &nbsp;
&nbsp;<A HREF="ExclusionStrategy.html" target="_top"><B>NO FRAMES</B></A> &nbsp;
&nbsp;<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:&nbsp;NESTED&nbsp;|&nbsp;FIELD&nbsp;|&nbsp;CONSTR&nbsp;|&nbsp;<A HREF="#method_summary">METHOD</A></FONT></TD>
<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
DETAIL:&nbsp;FIELD&nbsp;|&nbsp;CONSTR&nbsp;|&nbsp;<A HREF="#method_detail">METHOD</A></FONT></TD>
</TR>
</TABLE>
<A NAME="skip-navbar_top"></A>
<!-- ========= END OF TOP NAVBAR ========= -->
<HR>
<!-- ======== START OF CLASS DATA ======== -->
<H2>
<FONT SIZE="-1">
com.google.gson</FONT>
<BR>
Interface ExclusionStrategy</H2>
<HR>
<DL>
<DT><PRE>public interface <B>ExclusionStrategy</B></DL>
</PRE>
<P>
A strategy (or policy) definition that is used to decide whether or not a field or top-level
class should be serialized or deserialized as part of the JSON output/input. For serialization,
if the <A HREF="../../../com/google/gson/ExclusionStrategy.html#shouldSkipClass(java.lang.Class)"><CODE>shouldSkipClass(Class)</CODE></A> method returns false then that class or field type
will not be part of the JSON output. For deserialization, if <A HREF="../../../com/google/gson/ExclusionStrategy.html#shouldSkipClass(java.lang.Class)"><CODE>shouldSkipClass(Class)</CODE></A>
returns false, then it will not be set as part of the Java object structure.
<p>The following are a few examples that shows how you can use this exclusion mechanism.
<p><strong>Exclude fields and objects based on a particular class type:</strong>
<pre class="code">
private static class SpecificClassExclusionStrategy implements ExclusionStrategy {
private final Class&lt;?&gt; excludedThisClass;
public SpecificClassExclusionStrategy(Class&lt;?&gt; excludedThisClass) {
this.excludedThisClass = excludedThisClass;
}
public boolean shouldSkipClass(Class&lt;?&gt; clazz) {
return excludedThisClass.equals(clazz);
}
public boolean shouldSkipField(FieldAttributes f) {
return excludedThisClass.equals(f.getDeclaredClass());
}
}
</pre>
<p><strong>Excludes fields and objects based on a particular annotation:</strong>
<pre class="code">
public &#64interface FooAnnotation {
// some implementation here
}
// Excludes any field (or class) that is tagged with an "&#64FooAnnotation"
private static class FooAnnotationExclusionStrategy implements ExclusionStrategy {
public boolean shouldSkipClass(Class&lt;?&gt; clazz) {
return clazz.getAnnotation(FooAnnotation.class) != null;
}
public boolean shouldSkipField(FieldAttributes f) {
return f.getAnnotation(FooAnnotation.class) != null;
}
}
</pre>
<p>Now if you want to configure <code>Gson</code> to use a user defined exclusion strategy, then
the <code>GsonBuilder</code> is required. The following is an example of how you can use the
<code>GsonBuilder</code> to configure Gson to use one of the above sample:
<pre class="code">
ExclusionStrategy excludeStrings = new UserDefinedExclusionStrategy(String.class);
Gson gson = new GsonBuilder()
.setExclusionStrategies(excludeStrings)
.create();
</pre>
<p>For certain model classes, you may only want to serialize a field, but exclude it for
deserialization. To do that, you can write an <code>ExclusionStrategy</code> as per normal;
however, you would register it with the
<A HREF="../../../com/google/gson/GsonBuilder.html#addDeserializationExclusionStrategy(com.google.gson.ExclusionStrategy)"><CODE>GsonBuilder.addDeserializationExclusionStrategy(ExclusionStrategy)</CODE></A> method.
For example:
<pre class="code">
ExclusionStrategy excludeStrings = new UserDefinedExclusionStrategy(String.class);
Gson gson = new GsonBuilder()
.addDeserializationExclusionStrategy(excludeStrings)
.create();
</pre>
<P>
<P>
<DL>
<DT><B>Since:</B></DT>
<DD>1.4</DD>
<DT><B>Author:</B></DT>
<DD>Inderjeet Singh, Joel Leitch</DD>
<DT><B>See Also:</B><DD><A HREF="../../../com/google/gson/GsonBuilder.html#setExclusionStrategies(com.google.gson.ExclusionStrategy...)"><CODE>GsonBuilder.setExclusionStrategies(ExclusionStrategy...)</CODE></A>,
<A HREF="../../../com/google/gson/GsonBuilder.html#addDeserializationExclusionStrategy(com.google.gson.ExclusionStrategy)"><CODE>GsonBuilder.addDeserializationExclusionStrategy(ExclusionStrategy)</CODE></A>,
<A HREF="../../../com/google/gson/GsonBuilder.html#addSerializationExclusionStrategy(com.google.gson.ExclusionStrategy)"><CODE>GsonBuilder.addSerializationExclusionStrategy(ExclusionStrategy)</CODE></A></DL>
<HR>
<P>
<!-- ========== METHOD SUMMARY =========== -->
<A NAME="method_summary"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2">
<B>Method Summary</B></FONT></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/google/gson/ExclusionStrategy.html#shouldSkipClass(java.lang.Class)">shouldSkipClass</A></B>(<A HREF="http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</A>&lt;?&gt;&nbsp;clazz)</CODE>
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/google/gson/ExclusionStrategy.html#shouldSkipField(com.google.gson.FieldAttributes)">shouldSkipField</A></B>(<A HREF="../../../com/google/gson/FieldAttributes.html" title="class in com.google.gson">FieldAttributes</A>&nbsp;f)</CODE>
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</TD>
</TR>
</TABLE>
&nbsp;
<P>
<!-- ============ METHOD DETAIL ========== -->
<A NAME="method_detail"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
<B>Method Detail</B></FONT></TH>
</TR>
</TABLE>
<A NAME="shouldSkipField(com.google.gson.FieldAttributes)"><!-- --></A><H3>
shouldSkipField</H3>
<PRE>
boolean <B>shouldSkipField</B>(<A HREF="../../../com/google/gson/FieldAttributes.html" title="class in com.google.gson">FieldAttributes</A>&nbsp;f)</PRE>
<DL>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>f</CODE> - the field object that is under test
<DT><B>Returns:</B><DD>true if the field should be ignored; otherwise false</DL>
</DD>
</DL>
<HR>
<A NAME="shouldSkipClass(java.lang.Class)"><!-- --></A><H3>
shouldSkipClass</H3>
<PRE>
boolean <B>shouldSkipClass</B>(<A HREF="http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</A>&lt;?&gt;&nbsp;clazz)</PRE>
<DL>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>clazz</CODE> - the class object that is under test
<DT><B>Returns:</B><DD>true if the class should be ignored; otherwise false</DL>
</DD>
</DL>
<!-- ========= 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="../../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> &nbsp;<FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/ExclusionStrategy.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A>&nbsp;</TD>
<TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A>&nbsp;</TD>
</TR>
</TABLE>
</TD>
<TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM>
</EM>
</TD>
</TR>
<TR>
<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
&nbsp;PREV CLASS&nbsp;
&nbsp;<A HREF="../../../com/google/gson/FieldAttributes.html" title="class in com.google.gson"><B>NEXT CLASS</B></A></FONT></TD>
<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
<A HREF="../../../index.html?com/google/gson/ExclusionStrategy.html" target="_top"><B>FRAMES</B></A> &nbsp;
&nbsp;<A HREF="ExclusionStrategy.html" target="_top"><B>NO FRAMES</B></A> &nbsp;
&nbsp;<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:&nbsp;NESTED&nbsp;|&nbsp;FIELD&nbsp;|&nbsp;CONSTR&nbsp;|&nbsp;<A HREF="#method_summary">METHOD</A></FONT></TD>
<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
DETAIL:&nbsp;FIELD&nbsp;|&nbsp;CONSTR&nbsp;|&nbsp;<A HREF="#method_detail">METHOD</A></FONT></TD>
</TR>
</TABLE>
<A NAME="skip-navbar_bottom"></A>
<!-- ======== END OF BOTTOM NAVBAR ======= -->
<HR>
Copyright &#169; 2008-2011 <a href="http://www.google.com">Google, Inc.</a>. All Rights Reserved.
</BODY>
</HTML>