package com.fasterxml.jackson.jr.ob.impl;
import java.io.IOException;
import java.util.Iterator;
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.type.ResolvedType;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.jr.ob.JSON;
import com.fasterxml.jackson.jr.ob.JSONObjectException;
/**
* Convenience wrapper around {@link JSON} that implements {@link ObjectCodec}.
* Note that implementation is not complete, due to natural limitations of
* {@link JSON} and "simple" object binding.
*<p>
* The main use case is to give minimal context for other components that
* expect to get a {@link ObjectCodec}, such as {@link JsonParser} and
* {@link JsonGenerator}.
*/
public class JSONAsObjectCodec
extends ObjectCodec
{
protected final JSON _json;
protected final JsonFactory _jsonFactory;
protected final TreeCodec _treeCodec;
public JSONAsObjectCodec(JSON json) {
this(json, json.getStreamingFactory());
}
public JSONAsObjectCodec(JSON json, JsonFactory jf)
{
this(json, jf, json.getTreeCodec());
}
public JSONAsObjectCodec(JSON json, JsonFactory jf, TreeCodec treeCodec)
{
_json = json;
_jsonFactory = jf;
_treeCodec = treeCodec;
}
/*
/**********************************************************************
/* ObjectCodec: Object reads
/**********************************************************************
*/
@SuppressWarnings("unchecked")
@Override
public <T> T readValue(JsonParser jp, Class<T> valueType)
throws IOException, JsonProcessingException
{
Object ob = _json.anyFrom(jp);
_checkResultType(valueType, ob);
return (T) ob;
}
@Override
public <T> T readValue(JsonParser jp, TypeReference<?> valueTypeRef)
throws IOException, JsonProcessingException
{
throw _noTypeReference();
}
@SuppressWarnings("unchecked")
@Override
public <T> T readValue(JsonParser jp, ResolvedType valueType)
throws IOException, JsonProcessingException {
return (T) readValue(jp, valueType.getRawClass());
}
@Override
public <T> Iterator<T> readValues(JsonParser jp, Class<T> valueType)
throws IOException, JsonProcessingException {
// May be able to support in future but...
throw new JSONObjectException("Simple JSON does not support 'readValues()' methods");
}
@Override
public <T> Iterator<T> readValues(JsonParser jp,
TypeReference<?> valueTypeRef) throws IOException, JsonProcessingException
{
throw _noTypeReference();
}
@SuppressWarnings("unchecked")
@Override
public <T> Iterator<T> readValues(JsonParser jp, ResolvedType valueType)
throws IOException, JsonProcessingException {
return (Iterator<T>) readValues(jp, valueType.getRawClass());
}
protected JSONObjectException _noTypeReference() {
return new JSONObjectException("Simple JSON does not support use of TypeReference");
}
/*
/**********************************************************************
/* ObjectCodec: Object writes
/**********************************************************************
*/
@Override
public void writeValue(JsonGenerator jgen, Object value)
throws IOException, JsonProcessingException
{
_json.write(value, jgen);
}
/*
/**********************************************************************
/* ObjectCodec: Tree
/**********************************************************************
*/
@Override
public TreeNode createObjectNode() {
return _checkTreeCodec().createObjectNode();
}
@Override
public TreeNode createArrayNode() {
return _checkTreeCodec().createArrayNode();
}
@Override
public <T extends TreeNode> T readTree(JsonParser jp) throws IOException, JsonProcessingException
{
return _checkTreeCodec().readTree(jp);
}
@Override
public void writeTree(JsonGenerator jg, TreeNode tree)
throws IOException, JsonProcessingException
{
_checkTreeCodec().writeTree(jg, tree);
}
@Override
public JsonParser treeAsTokens(TreeNode n) {
return _checkTreeCodec().treeAsTokens(n);
}
@Override
public <T> T treeToValue(TreeNode n, Class<T> valueType)
throws JsonProcessingException
{
/* Without TokenBuffer from jackson-databind, need to actually
* create an intermediate textual representation. Fine,
* we should be able to do that. Bigger question is whether
* actual read works but...
*/
try {
String json = _json.asString(n);
JsonParser jp = _jsonFactory.createParser(json);
T result = readValue(jp, valueType);
jp.close();
return result;
} catch (JsonProcessingException e) { // to support [JACKSON-758]
throw e;
} catch (IOException e) { // shouldn't really happen, but is declared as possibility so:
throw JSONObjectException.fromUnexpectedIOE(e);
}
}
/*
/**********************************************************************
/* ObjectCodec: other
/**********************************************************************
*/
@Override
public JsonFactory getFactory() {
return _jsonFactory;
}
@Deprecated
@Override
public JsonFactory getJsonFactory() {
return _jsonFactory;
}
/*
/**********************************************************************
/* Internal methods
/**********************************************************************
*/
protected TreeCodec _checkTreeCodec()
{
TreeCodec c = _treeCodec;
if (c == null) {
throw new IllegalStateException("No TreeCodec has been configured: can not use tree operations");
}
return c;
}
protected void _checkResultType(Class<?> valueType, Object ob)
throws JSONObjectException
{
if (ob != null) {
if (!valueType.isAssignableFrom(ob.getClass())) {
throw new JSONObjectException("Simple JSON can only bind given JSON as "
+ob.getClass().getName()+", not as "+valueType.getName());
}
}
}
}