com.fasterxml.jackson.databind.deser.std.FromStringDeserializer Maven / Gradle / Ivy
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package com.fasterxml.jackson.databind.deser.std;
import java.io.*;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Currency;
import java.util.IllformedLocaleException;
import java.util.Locale;
import java.util.TimeZone;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.util.VersionUtil;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.cfg.CoercionAction;
import com.fasterxml.jackson.databind.cfg.CoercionInputShape;
import com.fasterxml.jackson.databind.exc.InvalidFormatException;
import com.fasterxml.jackson.databind.type.LogicalType;
import com.fasterxml.jackson.databind.util.ClassUtil;
/**
* Base class for simple deserializers that serialize values from String
* representation: this includes JSON Strings and other Scalar values that
* can be coerced into text, like Numbers and Booleans).
* Simple JSON String values are trimmed using {@link java.lang.String#trim}.
* Partial deserializer implementation will try to first access current token as
* a String, calls {@code _deserialize(String,DeserializationContext)} and
* returns return value.
* If this does not work (current token not a simple scalar type), attempts
* are made so that:
*
* - Embedded values ({@link JsonToken#VALUE_EMBEDDED_OBJECT}) are returned as-is
* if they are of compatible type
*
* - Arrays may be "unwrapped" if (and only if) {@link DeserializationFeature#UNWRAP_SINGLE_VALUE_ARRAYS}
* is enabled, and array contains just a single scalar value that can be deserialized
* (for example, JSON Array with single JSON String element).
*
*
*
* Special handling includes:
*
* - Null values ({@link JsonToken#VALUE_NULL}) are handled by returning value
* returned by {@link JsonDeserializer#getNullValue(DeserializationContext)}: default
* implementation simply returns Java `null` but this may be overridden.
*
* - Empty String (after trimming) will result in {@link #_deserializeFromEmptyString}
* getting called, and return value being returned as deserialization: default implementation
* simply returns `null`.
*
*
*/
@SuppressWarnings("serial")
public abstract class FromStringDeserializer extends StdScalarDeserializer
{
public static Class>[] types() {
return new Class>[] {
File.class,
URL.class,
URI.class,
Class.class,
JavaType.class,
Currency.class,
Pattern.class,
Locale.class,
Charset.class,
TimeZone.class,
InetAddress.class,
InetSocketAddress.class,
// Special impl:
StringBuilder.class,
StringBuffer.class, // since 2.13.3
};
}
/*
/**********************************************************
/* Life-cycle
/**********************************************************
*/
protected FromStringDeserializer(Class> vc) {
super(vc);
}
/**
* Factory method for trying to find a deserializer for one of supported
* types that have simple from-String serialization.
*/
public static FromStringDeserializer> findDeserializer(Class> rawType)
{
int kind = 0;
if (rawType == File.class) {
kind = Std.STD_FILE;
} else if (rawType == URL.class) {
kind = Std.STD_URL;
} else if (rawType == URI.class) {
kind = Std.STD_URI;
} else if (rawType == Class.class) {
kind = Std.STD_CLASS;
} else if (rawType == JavaType.class) {
kind = Std.STD_JAVA_TYPE;
} else if (rawType == Currency.class) {
kind = Std.STD_CURRENCY;
} else if (rawType == Pattern.class) {
kind = Std.STD_PATTERN;
} else if (rawType == Locale.class) {
kind = Std.STD_LOCALE;
} else if (rawType == Charset.class) {
kind = Std.STD_CHARSET;
} else if (rawType == TimeZone.class) {
kind = Std.STD_TIME_ZONE;
} else if (rawType == InetAddress.class) {
kind = Std.STD_INET_ADDRESS;
} else if (rawType == InetSocketAddress.class) {
kind = Std.STD_INET_SOCKET_ADDRESS;
} else if (rawType == StringBuilder.class) {
return new StringBuilderDeserializer();
} else if (rawType == StringBuffer.class) { // since 2.13.3
return new StringBufferDeserializer();
} else {
return null;
}
return new Std(rawType, kind);
}
@Override // since 2.12
public LogicalType logicalType() {
return LogicalType.OtherScalar;
}
/*
/**********************************************************
/* Deserializer implementations
/**********************************************************
*/
@SuppressWarnings("unchecked")
@Override
public T deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
{
// Let's get textual value, possibly via coercion from other scalar types
String text = p.getValueAsString();
if (text == null) {
JsonToken t = p.currentToken();
if (t != JsonToken.START_OBJECT) {
return (T) _deserializeFromOther(p, ctxt, t);
}
// 29-Jun-2020, tatu: New! "Scalar from Object" (mostly for XML)
text = ctxt.extractScalarFromObject(p, this, _valueClass);
}
if (text.isEmpty()) {
// 09-Jun-2020, tatu: Commonly `null` but may coerce to "empty" as well
return (T) _deserializeFromEmptyString(ctxt);
}
if (_shouldTrim()) {
final String old = text;
text = text.trim();
if (text != old) {
if (text.isEmpty()) {
return (T) _deserializeFromEmptyString(ctxt);
}
}
}
Exception cause = null;
try {
// 19-May-2017, tatu: Used to require non-null result (assuming `null`
// indicated error; but that seems wrong. Should be able to return
// `null` as value.
return _deserialize(text, ctxt);
} catch (IllegalArgumentException | MalformedURLException e) {
cause = e;
}
// note: `cause` can't be null
String msg = "not a valid textual representation";
String m2 = cause.getMessage();
if (m2 != null) {
msg = msg + ", problem: "+m2;
}
// 05-May-2016, tatu: Unlike most usage, this seems legit, so...
throw ctxt.weirdStringException(text, _valueClass, msg)
.withCause(cause);
}
/**
* Main method from trying to deserialize actual value from non-empty
* String.
*/
protected abstract T _deserialize(String value, DeserializationContext ctxt) throws IOException;
// @since 2.13.1
protected boolean _shouldTrim() {
return true;
}
// @since 2.12
protected Object _deserializeFromOther(JsonParser p, DeserializationContext ctxt,
JsonToken t) throws IOException
{
// [databind#381]
if (t == JsonToken.START_ARRAY) {
return _deserializeFromArray(p, ctxt);
}
if (t == JsonToken.VALUE_EMBEDDED_OBJECT) {
// Trivial cases; null to null, instance of type itself returned as is
Object ob = p.getEmbeddedObject();
if (ob == null) {
return null;
}
if (_valueClass.isAssignableFrom(ob.getClass())) {
return ob;
}
return _deserializeEmbedded(ob, ctxt);
}
return ctxt.handleUnexpectedToken(_valueClass, p);
}
/**
* Overridable method to allow coercion from embedded value that is neither
* {@code null} nor directly assignable to target type.
* Used, for example, by {@link UUIDDeserializer} to coerce from {@code byte[]}.
*/
protected T _deserializeEmbedded(Object ob, DeserializationContext ctxt) throws IOException {
// default impl: error out
ctxt.reportInputMismatch(this,
"Don't know how to convert embedded Object of type %s into %s",
ob.getClass().getName(), _valueClass.getName());
return null;
}
@Deprecated // since 2.12 -- override variant that takes context
protected final T _deserializeFromEmptyString() throws IOException {
return null;
}
/**
* @since 2.12
*/
protected Object _deserializeFromEmptyString(DeserializationContext ctxt) throws IOException {
CoercionAction act = ctxt.findCoercionAction(logicalType(), _valueClass,
CoercionInputShape.EmptyString);
if (act == CoercionAction.Fail) {
ctxt.reportInputMismatch(this,
"Cannot coerce empty String (\"\") to %s (but could if enabling coercion using `CoercionConfig`)",
_coercedTypeDesc());
}
if (act == CoercionAction.AsNull) {
return getNullValue(ctxt);
}
if (act == CoercionAction.AsEmpty) {
return getEmptyValue(ctxt);
}
// 09-Jun-2020, tatu: semantics for `TryConvert` are bit interesting due to
// historical reasons
return _deserializeFromEmptyStringDefault(ctxt);
}
/**
* @since 2.12
*/
protected Object _deserializeFromEmptyStringDefault(DeserializationContext ctxt) throws IOException {
// by default, "as-null", but overridable by sub-classes
return getNullValue(ctxt);
}
/*
/**********************************************************
/* A general-purpose implementation
/**********************************************************
*/
/**
* "Chameleon" deserializer that works on simple types that are deserialized
* from a simple String.
*
* @since 2.4
*/
public static class Std extends FromStringDeserializer