이 응용 프로그램 RomeCNN은 Rome 1.5.0을 사용하여 CNN 뉴스 피드를 반복하고 URL을 데이터베이스에 유지합니다. 데이터베이스가 중복 링크를 거부합니다.MySQLIntegrityConstraintViolationException 응용 프로그램이 다운 됨
유형 예외가 MySQLIntegrityConstraintViolationException
인 경우 해당 삽입이 데이터베이스에서 거부되어야합니다. 아마도 중복을 피하는 더 좋은 방법이있을 수 있지만, 지금은 충분합니다. (다른 문제가 발생하지 않는다면 "링크가 이미 존재하고 예외를 잡아서 다음으로 넘어 간다"라고 생각하고있었습니다.)
응용 프로그램이 충돌하는 이유는 무엇입니까? 무결성 제약 조건 위반의 특정 임계 값 이후에 연결이 끊어 졌습니까?
run:
[java] [EL Info]: 2014-11-03 01:20:39.432--ServerSession(28432534)--EclipseLink, version: Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd
[java] [EL Info]: connection: 2014-11-03 01:20:40.173--ServerSession(28432534)--file:/home/thufir/NetBeansProjects/RomeCNN/build/classes/_RomeReaderPU login successful
[java] [EL Warning]: 2014-11-03 01:20:40.405--UnitOfWork(6261946)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
[java] Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'http://rss.cnn.com/~r/rss/cnn_topstories/~3/WD5Aw61It7M/nr-kenya' for key 'UNQ_links_0'
[java] Error Code: 1062
[java] Call: INSERT INTO links.links (created, link, status) VALUES (?, ?, ?)
[java] bind => [3 parameters bound]
[java] Query: InsertObjectQuery(romereader.Link[ id=null ])
[java] Exception in thread "main" javax.persistence.RollbackException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
[java] Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'http://rss.cnn.com/~r/rss/cnn_topstories/~3/WD5Aw61It7M/nr-kenya' for key 'UNQ_links_0'
[java] Error Code: 1062
[java] Call: INSERT INTO links.links (created, link, status) VALUES (?, ?, ?)
[java] bind => [3 parameters bound]
[java] Query: InsertObjectQuery(romereader.Link[ id=null ])
[java] at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:157)
[java] at romereader.LinkJpaController.create(LinkJpaController.java:31)
[java] at romereader.Main.getLinks(Main.java:41)
[java] at romereader.Main.main(Main.java:21)
[java] Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
[java] Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'http://rss.cnn.com/~r/rss/cnn_topstories/~3/WD5Aw61It7M/nr-kenya' for key 'UNQ_links_0'
[java] Error Code: 1062
[java] Call: INSERT INTO links.links (created, link, status) VALUES (?, ?, ?)
[java] bind => [3 parameters bound]
[java] Query: InsertObjectQuery(romereader.Link[ id=null ])
[java] at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:331)
[java] at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:900)
[java] at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeNoSelect(DatabaseAccessor.java:962)
[java] at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:631)
[java] at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeCall(DatabaseAccessor.java:558)
[java] at org.eclipse.persistence.internal.sessions.AbstractSession.basicExecuteCall(AbstractSession.java:2002)
[java] at org.eclipse.persistence.sessions.server.ClientSession.executeCall(ClientSession.java:298)
[java] at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:242)
[java] at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:228)
[java] at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.insertObject(DatasourceCallQueryMechanism.java:377)
[java] at org.eclipse.persistence.internal.queries.StatementQueryMechanism.insertObject(StatementQueryMechanism.java:165)
[java] at org.eclipse.persistence.internal.queries.StatementQueryMechanism.insertObject(StatementQueryMechanism.java:180)
[java] at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.insertObjectForWrite(DatabaseQueryMechanism.java:489)
[java] at org.eclipse.persistence.queries.InsertObjectQuery.executeCommit(InsertObjectQuery.java:80)
[java] at org.eclipse.persistence.queries.InsertObjectQuery.executeCommitWithChangeSet(InsertObjectQuery.java:90)
[java] at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.executeWriteWithChangeSet(DatabaseQueryMechanism.java:301)
[java] at org.eclipse.persistence.queries.WriteObjectQuery.executeDatabaseQuery(WriteObjectQuery.java:58)
[java] at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:899)
[java] at org.eclipse.persistence.queries.DatabaseQuery.executeInUnitOfWork(DatabaseQuery.java:798)
[java] at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWorkObjectLevelModifyQuery(ObjectLevelModifyQuery.java:108)
[java] at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWork(ObjectLevelModifyQuery.java:85)
[java] at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2896)
[java] at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1804)
[java] at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1786)
[java] at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1737)
[java] at org.eclipse.persistence.internal.sessions.CommitManager.commitNewObjectsForClassWithChangeSet(CommitManager.java:226)
[java] at org.eclipse.persistence.internal.sessions.CommitManager.commitAllObjectsWithChangeSet(CommitManager.java:125)
[java] at org.eclipse.persistence.internal.sessions.AbstractSession.writeAllObjectsWithChangeSet(AbstractSession.java:4207)
[java] at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1441)
[java] at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithChangeSet(UnitOfWorkImpl.java:1531)
[java] at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.commitRootUnitOfWork(RepeatableWriteUnitOfWork.java:277)
[java] at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitAndResume(UnitOfWorkImpl.java:1169)
[java] at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:132)
[java] ... 3 more
[java] Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'http://rss.cnn.com/~r/rss/cnn_topstories/~3/WD5Aw61It7M/nr-kenya' for key 'UNQ_links_0'
[java] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
[java] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
[java] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
[java] at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
[java] at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
[java] at com.mysql.jdbc.Util.getInstance(Util.java:386)
[java] at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1040)
[java] at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4120)
[java] at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4052)
[java] at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2503)
[java] at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2664)
[java] at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2794)
[java] at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155)
[java] at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2458)
[java] at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2375)
[java] at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2359)
[java] at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:890)
[java] ... 34 more
[java] Java Result: 1
BUILD SUCCESSFUL
Total time: 6 seconds
[email protected]:~/NetBeansProjects/RomeCNN$
[email protected]:~/NetBeansProjects/RomeCNN$
JpaController : 삽입은이 중 제약 조건 위반 또는 특정 URL에 분명히된다는 이유를 데이터베이스로 만들어 동안
이package romereader;
import java.io.Serializable;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Query;
import javax.persistence.EntityNotFoundException;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import romereader.exceptions.NonexistentEntityException;
public class LinkJpaController implements Serializable {
public LinkJpaController(EntityManagerFactory emf) {
this.emf = emf;
}
private EntityManagerFactory emf = null;
public EntityManager getEntityManager() {
return emf.createEntityManager();
}
public void create(Link link) {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
em.persist(link);
em.getTransaction().commit();
} finally {
if (em != null) {
em.close();
}
}
}
public void edit(Link link) throws NonexistentEntityException, Exception {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
link = em.merge(link);
em.getTransaction().commit();
} catch (Exception ex) {
String msg = ex.getLocalizedMessage();
if (msg == null || msg.length() == 0) {
Integer id = link.getId();
if (findLink(id) == null) {
throw new NonexistentEntityException("The link with id " + id + " no longer exists.");
}
}
throw ex;
} finally {
if (em != null) {
em.close();
}
}
}
public void destroy(Integer id) throws NonexistentEntityException {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
Link link;
try {
link = em.getReference(Link.class, id);
link.getId();
} catch (EntityNotFoundException enfe) {
throw new NonexistentEntityException("The link with id " + id + " no longer exists.", enfe);
}
em.remove(link);
em.getTransaction().commit();
} finally {
if (em != null) {
em.close();
}
}
}
public List<Link> findLinkEntities() {
return findLinkEntities(true, -1, -1);
}
public List<Link> findLinkEntities(int maxResults, int firstResult) {
return findLinkEntities(false, maxResults, firstResult);
}
private List<Link> findLinkEntities(boolean all, int maxResults, int firstResult) {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
cq.select(cq.from(Link.class));
Query q = em.createQuery(cq);
if (!all) {
q.setMaxResults(maxResults);
q.setFirstResult(firstResult);
}
return q.getResultList();
} finally {
em.close();
}
}
public Link findLink(Integer id) {
EntityManager em = getEntityManager();
try {
return em.find(Link.class, id);
} finally {
em.close();
}
}
public int getLinkCount() {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
Root<Link> rt = cq.from(Link.class);
cq.select(em.getCriteriaBuilder().count(rt));
Query q = em.createQuery(cq);
return ((Long) q.getSingleResult()).intValue();
} finally {
em.close();
}
}
}
, 나에게 분명하지 않다.
persistence.xml
파일 : 나는 그렇게 같은 방법을 만들 업데이트
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="RomeReaderPU" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>romereader.Links</class>
<class>romereader.Link</class>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/links?zeroDateTimeBehavior=convertToNull"/>
<property name="javax.persistence.jdbc.password" value="password"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.user" value="jdbc"/>
</properties>
</persistence-unit>
</persistence>