spring date JPA动态条件查询

spring date Jpa 动态条件查询
构建动态sql前需要给Subscribe 实体 实现 Serializable
dao需要继承 extends JpaRepository, JpaSpecificationExecutor
主要代码：

 public Page findSubscribeByCondition(int i,String name,String phone,String date,String bwg){
        PageRequest page = PageRequest.of(i,10);
        Specification specification = new Specification() {
            @Override
            public Predicate toPredicate(Root root, CriteriaQuery criteriaQuery, CriteriaBuilder criteriaBuilder) {
                // 动态 SQL表达式
                Predicate predicate = criteriaBuilder.conjunction();
                // 动态 SQL表达式集合
                List> expressions = predicate.getExpressions();
                if(name != null || name != ""){
                    expressions.add(criteriaBuilder.like(root.get("name").as(String.class),"%"+name+"%"));
                }
                if(phone != null || phone != ""){
                    expressions.add(criteriaBuilder.equal(root.get("number").as(String.class),phone));
                }
                if(date != null || date != ""){
                    expressions.add(criteriaBuilder.equal(root.get("date").as(String.class),date));
                }
                if(bwg != null || bwg != ""){
                    expressions.add(criteriaBuilder.equal(root.get("bwg").as(String.class),bwg));
                }
                return predicate;
            }
        };
        return subscribeDao.findAll(specification, page);
    }