com.fasterxml.jackson.databind.deser.impl.JDKValueInstantiators Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including
all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and
Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
package com.fasterxml.jackson.databind.deser.impl;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import com.fasterxml.jackson.core.JsonLocation;
import com.fasterxml.jackson.databind.DeserializationConfig;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.deser.ValueInstantiator;
import com.fasterxml.jackson.databind.deser.std.JsonLocationInstantiator;
/**
* Container for a set of {@link ValueInstantiator}s used for certain critical
* JDK value types, either as performance optimization for initialization time observed
* by profiling, or due to difficulty in otherwise finding constructors.
*
* @since 2.10
*/
public abstract class JDKValueInstantiators
{
public static ValueInstantiator findStdValueInstantiator(DeserializationConfig config,
Class> raw)
{
if (raw == JsonLocation.class) {
return new JsonLocationInstantiator();
}
// [databind#1868]: empty List/Set/Map
// [databind#2416]: optimize commonly needed default creators
if (Collection.class.isAssignableFrom(raw)) {
if (raw == ArrayList.class) {
return ArrayListInstantiator.INSTANCE;
}
if (Collections.EMPTY_SET.getClass() == raw) {
return new ConstantValueInstantiator(Collections.EMPTY_SET);
}
if (Collections.EMPTY_LIST.getClass() == raw) {
return new ConstantValueInstantiator(Collections.EMPTY_LIST);
}
} else if (Map.class.isAssignableFrom(raw)) {
if (raw == LinkedHashMap.class) {
return LinkedHashMapInstantiator.INSTANCE;
}
if (raw == HashMap.class) {
return HashMapInstantiator.INSTANCE;
}
if (Collections.EMPTY_MAP.getClass() == raw) {
return new ConstantValueInstantiator(Collections.EMPTY_MAP);
}
}
return null;
}
private static class ArrayListInstantiator
extends ValueInstantiator.Base
implements java.io.Serializable
{
private static final long serialVersionUID = 2L;
public final static ArrayListInstantiator INSTANCE = new ArrayListInstantiator();
public ArrayListInstantiator() {
super(ArrayList.class);
}
@Override
public boolean canInstantiate() { return true; }
@Override
public boolean canCreateUsingDefault() { return true; }
@Override
public Object createUsingDefault(DeserializationContext ctxt) throws IOException {
return new ArrayList<>();
}
}
private static class HashMapInstantiator
extends ValueInstantiator.Base
implements java.io.Serializable
{
private static final long serialVersionUID = 2L;
public final static HashMapInstantiator INSTANCE = new HashMapInstantiator();
public HashMapInstantiator() {
super(HashMap.class);
}
@Override
public boolean canInstantiate() { return true; }
@Override
public boolean canCreateUsingDefault() { return true; }
@Override
public Object createUsingDefault(DeserializationContext ctxt) throws IOException {
return new HashMap<>();
}
}
private static class LinkedHashMapInstantiator
extends ValueInstantiator.Base
implements java.io.Serializable
{
private static final long serialVersionUID = 2L;
public final static LinkedHashMapInstantiator INSTANCE = new LinkedHashMapInstantiator();
public LinkedHashMapInstantiator() {
super(LinkedHashMap.class);
}
@Override
public boolean canInstantiate() { return true; }
@Override
public boolean canCreateUsingDefault() { return true; }
@Override
public Object createUsingDefault(DeserializationContext ctxt) throws IOException {
return new LinkedHashMap<>();
}
}
private static class ConstantValueInstantiator
extends ValueInstantiator.Base
implements java.io.Serializable
{
private static final long serialVersionUID = 2L;
protected final Object _value;
public ConstantValueInstantiator(Object value) {
super(value.getClass());
_value = value;
}
@Override // yes, since default ctor works
public boolean canInstantiate() { return true; }
@Override
public boolean canCreateUsingDefault() { return true; }
@Override
public Object createUsingDefault(DeserializationContext ctxt) throws IOException {
return _value;
}
}
}
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