Querydsl를 사용한 쿼리 결과를DTO로 받는 실습을 하고 있었다.
MemberDto
kage query.dsltest.exer.dto;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
@Getter @Setter @ToString
public class MemberDto
{
private String username;
private int age;
public MemberDto(String username, int age)
{
this.username =username;
this.age = age;
}
}
Test
@Test
@DisplayName("DTO 1")
void useDto1()
{
List<MemberDto> dto = jpaQueryFactory
.select(Projections.bean(MemberDto.class,member.username, member.age))
.from(member)
.fetch();
for (MemberDto memberDto : dto) {
System.out.println("memberDto.getAge() : "+memberDto.getAge());
System.out.println("memberDto.getUsername() : "+memberDto.getUsername());
}
}query.dsltest.exer.dto.MemberDto java.lang.InstantiationException: query.dsltest.exer.dto.MemberDto at java.base/java.lang.Class.newInstance(Class.java:639) at com.querydsl.core.types.QBean.create(QBean.java:251) at com.querydsl.core.types.QBean.newInstance(QBean.java:222) at com.querydsl.jpa.FactoryExpressionTransformer.transformTuple(FactoryExpressionTransformer.java:51) at org.hibernate.sql.results.internal.RowTransformerTupleTransformerAdapter.transformRow(RowTransformerTupleTransformerAdapter.java:30) at org.hibernate.sql.results.internal.StandardRowReader.readRow(StandardRowReader.java:98) at org.hibernate.sql.results.spi.ListResultsConsumer.consume(ListResultsConsumer.java:204) at org.hibernate.sql.results.spi.ListResultsConsumer.consume(ListResultsConsumer.java:33) at org.hibernate.sql.exec.internal.JdbcSelectExecutorStandardImpl.doExecuteQuery(JdbcSelectExecutorStandardImpl.java:209) at org.hibernate.sql.exec.internal.JdbcSelectExecutorStandardImpl.executeQuery(JdbcSelectExecutorStandardImpl.java:83) at org.hibernate.sql.exec.spi.JdbcSelectExecutor.list(JdbcSelectExecutor.java:76) at org.hibernate.sql.exec.spi.JdbcSelectExecutor.list(JdbcSelectExecutor.java:65) at org.hibernate.query.sqm.internal.ConcreteSqmSelectQueryPlan.lambda$new$2(ConcreteSqmSelectQueryPlan.java:137) at org.hibernate.query.sqm.internal.ConcreteSqmSelectQueryPlan.withCacheableSqmInterpretation(ConcreteSqmSelectQueryPlan.java:359) at org.hibernate.query.sqm.internal.ConcreteSqmSelectQueryPlan.performList(ConcreteSqmSelectQueryPlan.java:300) at org.hibernate.query.sqm.internal.QuerySqmImpl.doList(QuerySqmImpl.java:509) at org.hibernate.query.spi.AbstractSelectionQuery.list(AbstractSelectionQuery.java:427) at org.hibernate.query.Query.getResultList(Query.java:120) at com.querydsl.jpa.impl.AbstractJPAQuery.getResultList(AbstractJPAQuery.java:191) at com.querydsl.jpa.impl.AbstractJPAQuery.fetch(AbstractJPAQuery.java:243) at query.dsltest.exer.Section4.useDto1(Section4.java:111) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:568) at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:728) at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60) at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131) at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:156) at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:147) at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:86) at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(InterceptingExecutableInvoker.java:103) at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.lambda$invoke$0(InterceptingExecutableInvoker.java:93) at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106) at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64) at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45) at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37) at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:92) at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:86) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(TestMethodTestDescriptor.java:218) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:214) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:139) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:69) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141) at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138) at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95) at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141) at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138) at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95) at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141) at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138) at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95) at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35) at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57) at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54) at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107) at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88) at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54) at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67) at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86) at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86) at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:119) at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:94) at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:89) at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:62) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:568) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33) at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94) at jdk.proxy1/jdk.proxy1.$Proxy2.stop(Unknown Source) at org.gradle.api.internal.tasks.testing.worker.TestWorker$3.run(TestWorker.java:193) at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:129) at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:100) at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:60) at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56) at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:113) at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:65) at worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69) at worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74) Caused by: java.lang.NoSuchMethodException: query.dsltest.exer.dto.MemberDto.<init>() at java.base/java.lang.Class.getConstructor0(Class.java:3585) at java.base/java.lang.Class.newInstance(Class.java:626) ... 104 more다음과 같은 예외가 발생했다.
왜그런가 찾아보다가 QueryDsl 이 쿼리를 생성할 때reflection을 사용하고 이때 기본 생성자가 존재하지 않으면 인스reflection를 사용할 수 없기 때문이다,
package query.dsltest.exer.dto;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
@Getter @Setter @ToString
public class MemberDto
{
private String username;
private int age;
public MemberDto(String username, int age)
{
this.username =username;
this.age = age;
}
public MemberDto()
{}
}memberDto.getAge() : 10
memberDto.getUsername() : member1
memberDto.getAge() : 20
memberDto.getUsername() : member2
memberDto.getAge() : 30
memberDto.getUsername() : member3
memberDto.getAge() : 40
memberDto.getUsername() : member4
정상적으로 작동이 된다!
