avro schema LocalDate mapping - date

Question

How to map avro schema to a LocalDate / LocaldateTime?
The spec says we can use logicalType. But DOES NOT CARE TO SHOW AN EXAMPLE of how it maps to LocalDate in Java. Why is a good example not part of the spec? that is for the specwriters.
Anyay
e.g.
{"namespace": "example.avro",
"type": "record",
"name": "User",
"fields": [
{"name": "date", "type": "int", "logicalType": "date"}
]
}
This maps to int and not to LocalDate e.g,
How to map in avro schema LocalDate?
#org.apache.avro.specific.AvroGenerated
public class User extends org.apache.avro.specific.SpecificRecordBase implements
org.apache.avro.specific.SpecificRecord {
private int date;// This should be LocalDate
}

Answer 1

{
"namespace": "example.avro",
"type": "record",
"name": "User",
"fields": [
{
"name": "date",
"type": {
"type": "int",
"logicalType": "date"
}
}
]
}
//this will generate following mapping to private java.time.LocalDate date;as below with maven-avro-plugin.
/**
* Autogenerated by Avro
*
* DO NOT EDIT DIRECTLY
*/
package example.avro;
import org.apache.avro.generic.GenericArray;
import org.apache.avro.specific.SpecificData;
import org.apache.avro.util.Utf8;
import org.apache.avro.message.BinaryMessageEncoder;
import org.apache.avro.message.BinaryMessageDecoder;
import org.apache.avro.message.SchemaStore;
#org.apache.avro.specific.AvroGenerated
public class User extends org.apache.avro.specific.SpecificRecordBase implements org.apache.avro.specific.SpecificRecord {
private static final long serialVersionUID = -2875816324033601436L;
public static final org.apache.avro.Schema SCHEMA$ = new org.apache.avro.Schema.Parser().parse("{\"type\":\"record\",\"name\":\"User\",\"namespace\":\"example.avro\",\"fields\":[{\"name\":\"date\",\"type\":{\"type\":\"int\",\"logicalType\":\"date\"}}]}");
public static org.apache.avro.Schema getClassSchema() { return SCHEMA$; }
private static SpecificData MODEL$ = new SpecificData();
static {
MODEL$.addLogicalTypeConversion(new org.apache.avro.data.TimeConversions.DateConversion());
}
private static final BinaryMessageEncoder<User> ENCODER =
new BinaryMessageEncoder<User>(MODEL$, SCHEMA$);
private static final BinaryMessageDecoder<User> DECODER =
new BinaryMessageDecoder<User>(MODEL$, SCHEMA$);
/**
* Return the BinaryMessageEncoder instance used by this class.
* #return the message encoder used by this class
*/
public static BinaryMessageEncoder<User> getEncoder() {
return ENCODER;
}
/**
* Return the BinaryMessageDecoder instance used by this class.
* #return the message decoder used by this class
*/
public static BinaryMessageDecoder<User> getDecoder() {
return DECODER;
}
/**
* Create a new BinaryMessageDecoder instance for this class that uses the specified {#link SchemaStore}.
* #param resolver a {#link SchemaStore} used to find schemas by fingerprint
* #return a BinaryMessageDecoder instance for this class backed by the given SchemaStore
*/
public static BinaryMessageDecoder<User> createDecoder(SchemaStore resolver) {
return new BinaryMessageDecoder<User>(MODEL$, SCHEMA$, resolver);
}
/**
* Serializes this User to a ByteBuffer.
* #return a buffer holding the serialized data for this instance
* #throws java.io.IOException if this instance could not be serialized
*/
public java.nio.ByteBuffer toByteBuffer() throws java.io.IOException {
return ENCODER.encode(this);
}
/**
* Deserializes a User from a ByteBuffer.
* #param b a byte buffer holding serialized data for an instance of this class
* #return a User instance decoded from the given buffer
* #throws java.io.IOException if the given bytes could not be deserialized into an instance of this class
*/
public static User fromByteBuffer(
java.nio.ByteBuffer b) throws java.io.IOException {
return DECODER.decode(b);
}
private java.time.LocalDate date;
/**
* Default constructor. Note that this does not initialize fields
* to their default values from the schema. If that is desired then
* one should use <code>newBuilder()</code>.
*/
public User() {}
/**
* All-args constructor.
* #param date The new value for date
*/
public User(java.time.LocalDate date) {
this.date = date;
}
public org.apache.avro.specific.SpecificData getSpecificData() { return MODEL$; }
public org.apache.avro.Schema getSchema() { return SCHEMA$; }
// Used by DatumWriter. Applications should not call.
public java.lang.Object get(int field$) {
switch (field$) {
case 0: return date;
default: throw new IndexOutOfBoundsException("Invalid index: " + field$);
}
}
private static final org.apache.avro.Conversion<?>[] conversions =
new org.apache.avro.Conversion<?>[] {
new org.apache.avro.data.TimeConversions.DateConversion(),
null
};
#Override
public org.apache.avro.Conversion<?> getConversion(int field) {
return conversions[field];
}
// Used by DatumReader. Applications should not call.
#SuppressWarnings(value="unchecked")
public void put(int field$, java.lang.Object value$) {
switch (field$) {
case 0: date = (java.time.LocalDate)value$; break;
default: throw new IndexOutOfBoundsException("Invalid index: " + field$);
}
}
/**
* Gets the value of the 'date' field.
* #return The value of the 'date' field.
*/
public java.time.LocalDate getDate() {
return date;
}
/**
* Sets the value of the 'date' field.
* #param value the value to set.
*/
public void setDate(java.time.LocalDate value) {
this.date = value;
}
/**
* Creates a new User RecordBuilder.
* #return A new User RecordBuilder
*/
public static example.avro.User.Builder newBuilder() {
return new example.avro.User.Builder();
}
/**
* Creates a new User RecordBuilder by copying an existing Builder.
* #param other The existing builder to copy.
* #return A new User RecordBuilder
*/
public static example.avro.User.Builder newBuilder(example.avro.User.Builder other) {
if (other == null) {
return new example.avro.User.Builder();
} else {
return new example.avro.User.Builder(other);
}
}
/**
* Creates a new User RecordBuilder by copying an existing User instance.
* #param other The existing instance to copy.
* #return A new User RecordBuilder
*/
public static example.avro.User.Builder newBuilder(example.avro.User other) {
if (other == null) {
return new example.avro.User.Builder();
} else {
return new example.avro.User.Builder(other);
}
}
/**
* RecordBuilder for User instances.
*/
#org.apache.avro.specific.AvroGenerated
public static class Builder extends org.apache.avro.specific.SpecificRecordBuilderBase<User>
implements org.apache.avro.data.RecordBuilder<User> {
private java.time.LocalDate date;
/** Creates a new Builder */
private Builder() {
super(SCHEMA$);
}
/**
* Creates a Builder by copying an existing Builder.
* #param other The existing Builder to copy.
*/
private Builder(example.avro.User.Builder other) {
super(other);
if (isValidValue(fields()[0], other.date)) {
this.date = data().deepCopy(fields()[0].schema(), other.date);
fieldSetFlags()[0] = other.fieldSetFlags()[0];
}
}
/**
* Creates a Builder by copying an existing User instance
* #param other The existing instance to copy.
*/
private Builder(example.avro.User other) {
super(SCHEMA$);
if (isValidValue(fields()[0], other.date)) {
this.date = data().deepCopy(fields()[0].schema(), other.date);
fieldSetFlags()[0] = true;
}
}
/**
* Gets the value of the 'date' field.
* #return The value.
*/
public java.time.LocalDate getDate() {
return date;
}
/**
* Sets the value of the 'date' field.
* #param value The value of 'date'.
* #return This builder.
*/
public example.avro.User.Builder setDate(java.time.LocalDate value) {
validate(fields()[0], value);
this.date = value;
fieldSetFlags()[0] = true;
return this;
}
/**
* Checks whether the 'date' field has been set.
* #return True if the 'date' field has been set, false otherwise.
*/
public boolean hasDate() {
return fieldSetFlags()[0];
}
/**
* Clears the value of the 'date' field.
* #return This builder.
*/
public example.avro.User.Builder clearDate() {
fieldSetFlags()[0] = false;
return this;
}
#Override
#SuppressWarnings("unchecked")
public User build() {
try {
User record = new User();
record.date = fieldSetFlags()[0] ? this.date : (java.time.LocalDate) defaultValue(fields()[0]);
return record;
} catch (org.apache.avro.AvroMissingFieldException e) {
throw e;
} catch (java.lang.Exception e) {
throw new org.apache.avro.AvroRuntimeException(e);
}
}
}
#SuppressWarnings("unchecked")
private static final org.apache.avro.io.DatumWriter<User>
WRITER$ = (org.apache.avro.io.DatumWriter<User>)MODEL$.createDatumWriter(SCHEMA$);
#Override public void writeExternal(java.io.ObjectOutput out)
throws java.io.IOException {
WRITER$.write(this, SpecificData.getEncoder(out));
}
#SuppressWarnings("unchecked")
private static final org.apache.avro.io.DatumReader<User>
READER$ = (org.apache.avro.io.DatumReader<User>)MODEL$.createDatumReader(SCHEMA$);
#Override public void readExternal(java.io.ObjectInput in)
throws java.io.IOException {
READER$.read(this, SpecificData.getDecoder(in));
}
}