Hibernate + JPA + guice实体不会持久存入数据库

Question

我现在正在使用hibernate，JPA和guice来实现持久性。当我尝试在html页面上创建一个实体时，它不会抛出任何错误，但是在数据库中找不到数据。实际上该实体已创建，但我不知道它保存在哪里。因为当我尝试使用相同的主键创建实体时，它会跳转到entityexistsexception。

service.java

package com.edit.foo.service;

import com.edit.common.domain.Party;
import com.edit.foo.persistence.PartyStore;
import com.google.inject.persist.Transactional;
import org.apache.commons.lang.StringUtils;

import javax.inject.Inject;
import javax.inject.Singleton;
import java.util.List;

@Singleton
public class PartyService {

private final PartyStore store;

@Inject
public PartyService (PartyStore store) {
    this.store = store;
}

@Transactional
public Party findById(String key) {
    if (StringUtils.isBlank(key))
        throw new IllegalArgumentException("");
    return store.findById(key);
}

@Transactional
public List<Party> search(String filter) {
    if (StringUtils.isBlank(filter))
        throw new IllegalArgumentException("");
    return store.findAllWithNameContaining(filter);
}

@Transactional
public Party create(Party party) {
    return store.create(party);
}

@Transactional
public Party update(Party party) {
    return store.update(party);
}
}

接口

package com.edit.foo.persistence;

import com.google.inject.persist.Transactional;
import javax.inject.Inject;
import javax.persistence.EntityManager;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import java.util.List;

public abstract class HibernatePersistentStore<E> implements PersistentStore<E> {
private final Class<E> clazz;

@Inject
protected EntityManager entityManager;

protected HibernatePersistentStore(Class<E> clazz) {
    this.clazz = clazz;
}

@Override
public E findById(String id) {
    return entityManager.find(clazz, id);
}

@Transactional
@Override
public List<E> findAll(Specification<E> filter) {
    CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
    CriteriaQuery<E> criteriaQuery = criteriaBuilder.createQuery(clazz);
    Root<E> root = criteriaQuery.from(clazz);

    criteriaQuery.select(root).where(
            filter.toPredicate(root, criteriaQuery, criteriaBuilder)
    );

    return entityManager
            .createQuery(criteriaQuery)
            .getResultList();
}

@Transactional
@Override
public E create(E entity) {
    entityManager.persist(entity);
    return entity;
}

@Transactional
@Override
public E update(E entity) {
    return entityManager.merge(entity);
}
}

这可能是什么原因？