Я пытаюсь написать объектный запрос с JDBI, чтобы иметь дело с отношением один-ко-многим. Как видно из документации, reduceRows
- это способ сделать это. Но я получил эти ошибки, обвиняя конструктора;
Обновление: оставьте по одному конструктору для каждой сущности.
Я проверил 2 кода из документов и получил следующие трассировки стека:
get1
Exception in thread "main" java.lang.IllegalArgumentException: Could not find column mapper for type 'join.AppJoin' of parameter 'c_id' for instance factory 'public join.AppJoin$Contact(join.AppJoin,int,java.lang.String)'
at org.jdbi.v3.core.mapper.reflect.ConstructorMapper.lambda$specialize0$3(ConstructorMapper.java:231)
at java.base/java.util.Optional.orElseThrow(Optional.java:408)
at org.jdbi.v3.core.mapper.reflect.ConstructorMapper.specialize0(ConstructorMapper.java:230)
at org.jdbi.v3.core.mapper.reflect.ConstructorMapper.specialize(ConstructorMapper.java:189)
at org.jdbi.v3.core.result.internal.RowViewImpl.rowMapperFor(RowViewImpl.java:63)
at org.jdbi.v3.core.result.internal.RowViewImpl.getRow(RowViewImpl.java:50)
at org.jdbi.v3.core.result.RowView.getRow(RowView.java:35)
at join.AppJoin.lambda$get1$0(AppJoin.java:70)
get2
Exception in thread "main" java.lang.NoSuchMethodException: no such constructor: join.AppJoin$Contact.<init>()void/newInvokeSpecial
at java.base/java.lang.invoke.MemberName.makeAccessException(MemberName.java:961)
at java.base/java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:1101)
at java.base/java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:2030)
at java.base/java.lang.invoke.MethodHandles$Lookup.findConstructor(MethodHandles.java:1264)
at org.jdbi.v3.core.mapper.reflect.internal.BeanPropertiesFactory$BeanPojoProperties$PropertiesHolder.<init>(BeanPropertiesFactory.java:200)
at org.jdbi.v3.core.config.JdbiCaches.lambda$declare$0(JdbiCaches.java:49)
at org.jdbi.v3.core.config.JdbiCaches$1.lambda$get$1(JdbiCaches.java:63)
at java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1705)
at org.jdbi.v3.core.config.JdbiCaches$1.get(JdbiCaches.java:63)
at org.jdbi.v3.core.mapper.reflect.internal.BeanPropertiesFactory$BeanPojoProperties.getProperties(BeanPropertiesFactory.java:81)
at org.jdbi.v3.core.mapper.reflect.internal.PojoMapper.specialize0(PojoMapper.java:99)
at org.jdbi.v3.core.mapper.reflect.internal.PojoMapper.specialize(PojoMapper.java:80)
at org.jdbi.v3.core.result.internal.RowViewImpl.rowMapperFor(RowViewImpl.java:63)
at org.jdbi.v3.core.result.internal.RowViewImpl.getRow(RowViewImpl.java:50)
at org.jdbi.v3.core.result.RowView.getRow(RowView.java:35)
at join.AppJoin.lambda$getList$1(AppJoin.java:92)
at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1133)
at join.AppJoin.lambda$getList$2(AppJoin.java:90)
at org.jdbi.v3.core.result.ResultBearing.lambda$reduceRows$5(ResultBearing.java:236)
Мой код:
import org.jdbi.v3.core.Handle;
import org.jdbi.v3.core.Jdbi;
import org.jdbi.v3.core.mapper.reflect.BeanMapper;
import org.jdbi.v3.core.mapper.reflect.ColumnName;
import org.jdbi.v3.core.mapper.reflect.ConstructorMapper;
import org.jdbi.v3.core.result.RowView;
import org.jdbi.v3.sqlobject.SqlObjectPlugin;
import java.beans.ConstructorProperties;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import static java.util.stream.Collectors.toList;
public class AppJoin {
public static void main(final String[] args) {
Properties properties = new Properties();
properties.setProperty("username", "sa");
properties.setProperty("password", "");
Jdbi jdbi = Jdbi.create("jdbc:h2:mem:testDB", properties);
jdbi.installPlugin(new SqlObjectPlugin());
try (final var handle = jdbi.open()) {
String sqlc1 = "CREATE TABLE contacts ( \n" +
" id BIGSERIAL PRIMARY KEY, \n" +
" name VARCHAR(255)\n" +
")";
String sqlc2 = "CREATE TABLE phones ( \n" +
" id BIGSERIAL PRIMARY KEY, \n" +
" phone VARCHAR(255), \n" +
" contactId int, \n" +
" foreign key (contactId) references contacts(id) on delete cascade \n" +
")";
handle.createUpdate(sqlc1).execute();
handle.createUpdate(sqlc2).execute();
handle.createUpdate("insert into contacts (name) values (:name)")
.bind("name", "str")
.execute();
handle.createUpdate("insert into phones (phone, contactId) values (:phone, :contactId)")
.bind("phone", "1111111")
.bind("contactId", "1")
.execute();
// List<Contact> list = handle.select("select id, name from contacts")
// .mapToBean(Contact.class).list();
// System.out.println(list);
System.out.println(get1(handle));
// System.out.println(get2(handle));
}
}
private static Contact get1(Handle handle) {
return handle.createQuery("select contacts.id c_id, name c_name, "
+ "phones.id p_id, phones.phone p_phone "
+ "from contacts left join phones on contacts.id = phones.contactId "
+ "where contacts.id = :id")
.bind("id", 1)
.registerRowMapper(ConstructorMapper.factory(Contact.class, "c_"))
.registerRowMapper(ConstructorMapper.factory(Phone.class, "p_"))
.reduceRows(null, (contact, rowView) -> {
if (contact == null) {
contact = rowView.getRow(Contact.class);
}
if (rowView.getColumn("p_id", Integer.class) != null) {
contact.addPhone(rowView.getRow(Phone.class));
}
return contact;
});
}
private static List<Contact> get2(Handle handle) {
return handle.createQuery(
"select contacts.id c_id, name c_name, phones.id p_id, phones.phone p_phone "
+ " from contacts "
+ " left join phones on contacts.id = phones.contactId ")
.registerRowMapper(BeanMapper.factory(Contact.class, "c"))
.registerRowMapper(BeanMapper.factory(Phone.class, "p"))
.reduceRows((Map<Long, Contact> map, RowView rowView) -> {
Contact contact = map.computeIfAbsent(
rowView.getColumn("c_id", Long.class),
id -> rowView.getRow(Contact.class));
if (rowView.getColumn("p_id", Long.class) != null) {
contact.addPhone(rowView.getRow(Phone.class));
}
})
.collect(toList());
}
public class Contact {
@ColumnName("id")
private final int id;
@ColumnName("name")
private final String name;
@ColumnName("phones")
private List<Phone> phones;
@ConstructorProperties({"id", "name"})
public Contact(int id, String name) {
this.id = id;
this.name = name;
this.phones = new ArrayList<>();
}
public int getId() {
return id;
}
public String getName() {
return name;
}
public List<Phone> getPhones() {
return phones;
}
public void addPhone(Phone phone) {
phones.add(phone);
}
@Override
public String toString() {
return "Contact{" +
"id=" + id +
", name='" + name + '\'' +
", phones=" + phones +
'}';
}
}
public class Phone {
@ColumnName("id")
private final int id;
@ColumnName("phone")
private final String phone;
@ConstructorProperties({"id", "phone"})
public Phone(int id, String phone) {
this.id = id;
this.phone = phone;
}
public int getId() {
return id;
}
public String getPhone() {
return phone;
}
@Override
public String toString() {
return "Phone{" +
"id=" + id +
", phone='" + phone + '\'' +
'}';
}
}
}
Зависимости Gradle:
compile "com.h2database:h2:1.4.199"
compile group: 'org.jdbi', name: 'jdbi3-core', version: '3.12.2'
compile group: 'org.jdbi', name: 'jdbi3-sqlobject', version: '3.12.2'
Буду признателен за любую помощь / кто-то, указывающий мне в правильном направлении! Можно ли это сделать в интерфейсе Дао?