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JsonSerializer (Gson 1.2 API)
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com.google.gson</FONT>
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Interface JsonSerializer&lt;T&gt;</H2>
<DL>
<DT><DT><B>Type Parameters:</B><DD><CODE>T</CODE> - type for which the serializer is being registered. It is possible that a serializer
may be asked to serialize a specific generic type of the T.</DL>
<HR>
<DL>
<DT><PRE>public interface <B>JsonSerializer&lt;T&gt;</B></DL>
</PRE>
<P>
Interface representing a custom serializer for Json. You should write a custom serializer, if
you are not happy with the default serialization done by Gson. You will also need to register
this serializer through <A HREF="../../../com/google/gson/GsonBuilder.html#registerTypeAdapter(java.lang.reflect.Type, java.lang.Object)"><CODE>GsonBuilder.registerTypeAdapter(Type, Object)</CODE></A>.
<p>Let us look at example where defining a serializer will be useful. The <code>Id</code> class
defined below has two fields: <code>clazz</code> and <code>value</code>.</p>
<p><pre>
public class Id&lt;T&gt; {
private final Class&lt;T&gt; clazz;
private final long value;
public Id(Class&lt;T&gt; clazz, long value) {
this.clazz = clazz;
this.value = value;
}
public long getValue() {
return value;
}
}
</pre></p>
<p>The default serialization of <code>Id(com.foo.MyObject.class, 20L)</code> will be
<code>{"clazz":com.foo.MyObject,"value":20}</code>. Suppose, you just want the output to be
the value instead, which is <code>20</code> in this case. You can achieve that by writing a custom
serializer:</p>
<p><pre>
class IdSerializer implements JsonSerializer&lt;Id&gt;() {
public JsonElement toJson(Id id, Type typeOfId, JsonSerializationContext context) {
return new JsonPrimitive(id.getValue());
}
}
</pre></p>
<p>You will also need to register <code>IdSerializer</code> with Gson as follows:</p>
<pre>
Gson gson = new GsonBuilder().registerTypeAdapter(Id.class, new IdSerializer()).create();
</pre>
<P>
<P>
<DL>
<DT><B>Author:</B></DT>
<DD>Inderjeet Singh, Joel Leitch</DD>
</DL>
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<B>Method Summary</B></FONT></TH>
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<CODE>&nbsp;<A HREF="../../../com/google/gson/JsonElement.html" title="class in com.google.gson">JsonElement</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/google/gson/JsonSerializer.html#serialize(T, java.lang.reflect.Type, com.google.gson.JsonSerializationContext)">serialize</A></B>(<A HREF="../../../com/google/gson/JsonSerializer.html" title="type parameter in JsonSerializer">T</A>&nbsp;src,
<A HREF="http://java.sun.com/j2se/1.5.0/docs/api/java/lang/reflect/Type.html?is-external=true" title="class or interface in java.lang.reflect">Type</A>&nbsp;typeOfSrc,
<A HREF="../../../com/google/gson/JsonSerializationContext.html" title="interface in com.google.gson">JsonSerializationContext</A>&nbsp;context)</CODE>
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Gson invokes this call-back method during serialization when it encounters a field of the
specified type.</TD>
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<A NAME="serialize(java.lang.Object,java.lang.reflect.Type,com.google.gson.JsonSerializationContext)"><!-- --></A><A NAME="serialize(T, java.lang.reflect.Type, com.google.gson.JsonSerializationContext)"><!-- --></A><H3>
serialize</H3>
<PRE>
<A HREF="../../../com/google/gson/JsonElement.html" title="class in com.google.gson">JsonElement</A> <B>serialize</B>(<A HREF="../../../com/google/gson/JsonSerializer.html" title="type parameter in JsonSerializer">T</A>&nbsp;src,
<A HREF="http://java.sun.com/j2se/1.5.0/docs/api/java/lang/reflect/Type.html?is-external=true" title="class or interface in java.lang.reflect">Type</A>&nbsp;typeOfSrc,
<A HREF="../../../com/google/gson/JsonSerializationContext.html" title="interface in com.google.gson">JsonSerializationContext</A>&nbsp;context)</PRE>
<DL>
<DD>Gson invokes this call-back method during serialization when it encounters a field of the
specified type.
<p>In the implementation of this call-back method, you should consider invoking
<A HREF="../../../com/google/gson/JsonSerializationContext.html#serialize(java.lang.Object, java.lang.reflect.Type)"><CODE>JsonSerializationContext.serialize(Object, Type)</CODE></A> method to create JsonElements for any
non-trivial field of the <code>src</code> object. However, you should never invoke it on the
<code>src</code> object itself since that will cause an infinite loop (Gson will call your
call-back method again).</p>
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>src</CODE> - the object that needs to be converted to Json.<DD><CODE>typeOfSrc</CODE> - the actual type (fully genericized version) of the source object.
<DT><B>Returns:</B><DD>a JsonElement corresponding to the specified object.</DL>
</DD>
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