方式一

new Specification匿名内部类，通过实现该匿名内部类的toPredicate方法构建查询sql

Specification<T> specification = new Specification<T>() {@Overridepublic Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder cb) {List<Predicate> predicateList = new ArrayList<Predicate>();predicateList.add(cb.equal(root.get("col1").as(String.class), "0"));predicateList.add(cb.equal(root.get("col2").as(String.class), "5"));predicateList.add(cb.equal(root.get("col3").as(String.class), t));// 构建(col4 != '24' or col3 is null)条件predicateList.add(cb.or(cb.notEqual(root.get("col4").as(String.class), "24"),cb.isNull(root.get("col4").as(String.class))));if (map.get("col4") != null){predicateList.add(cb.equal(root.get("col4").as(String.class), map.get("col4")));}if (map.get("col5") != null){predicateList.add(cb.equal(root.get("col5").as(String.class), map.get("col5")));}if (map.get("col6") != null){predicateList.add(cb.equal(root.get("col6").as(String.class), map.get("col6")));}if (map.get("col7") != null){predicateList.add(cb.equal(root.get("col7").as(String.class), map.get("col7")));}if (map.get("col8") != null){predicateList.add(cb.like(root.get("col8").as(String.class), "%" + map.get("col8").toString().trim() + "%"));}if (map.get("col9") != null){Object obj = map.get("col9");if (obj instanceof List){List list = (List) obj;List<Integer> orgList = new ArrayList<>();list.forEach(o -> {if (o != null){try{orgList.add(Integer.valueOf(o.toString()));}catch (NumberFormatException e){log.error("传参col9格式错误");}}});if (!orgList.isEmpty()){predicateList.add(root.get("col").as(Integer.class).in(list));}}}Predicate[] p = new Predicate[predicateList.size()];query.where(predicateList.toArray(p));query.orderBy(cb.desc(root.get("id").as(Integer.class)));return query.getRestriction();}};Pageable pageable = PageRequest.of(page, size);
// 得到查询结果
Page<T> pageResult = tDao.findAll(specification, pageable);

方式二

根据参数组装sql条件，设置对应位置参数。缺点：in查询支持比较麻烦

@PersistenceContext
private EntityManager entityManager;// 构建in查询sql,使用list接收参数,为后续设置对应位置参数
Object obj = map.get("list");
if (obj instanceof List){sql.append(" and col in (");List orgList = (List) obj;orgList.forEach(o -> {queryCondition.add(o);});sql.append(orgList.stream().map(o -> "?").collect(Collectors.joining(","))).append(")");
}// 普通查询条件构建
if (!isNullOrBlank(String.valueOf(map.get("col2")))) {sql.append(" and col2= ?");queryCondition.add(map.get("col2"));
}// 根据sql List<Object> queryCondition list,
Query query = entityManager.createNativeQuery(sql,clazz);
query.setFirstResult((int) pageable.getOffset());
query.setMaxResults(pageable.getPageSize());for (int batch = 0; batch < queryCondition.size(); batch++) {query.setParameter(batch + 1,queryCondition.get(batch));
}