JPA使用Specification like查询时特殊字符%和_处理问题 Escape示例

当使用JPA的Specification处理like查询时，如果含有特殊字符%和_，则需要使用以下API处理问题：

hibernate-jpa-2.1-api-1.0.2.Final.jar

Predicate like(Expression<String> var1, String var2, char var3);第三个参数是escape关键字，必须是char。此api存在hibernate-jpa-2.1-api-1.0.2.Final.jar包的CriteriaBuilder中。代码如下：

 Map para = new HashMap();
        para.put("isSoftDel", 0);        
        para.put("title", title);
        
        Sort sort = new Sort(Sort.Direction.DESC, "createTime");
        Page pageInfo = repository.findAll(service.getSpecificationForPage(para), getPageable(limit, page, sort));

　　

public Specification getSpecificationForPage(Map para) {
        return new Specification() {
            @Override
            public Predicate toPredicate(Root root, CriteriaQuery query, CriteriaBuilder criteriaBuilder) {
                List<Predicate> list = new ArrayList<>();              

                Predicate predicate1 = criteriaBuilder.and(criteriaBuilder.equal(createBy, para.get("createBy")));
                Predicate predicate2 = criteriaBuilder.and(criteriaBuilder.notEqual(createBy, para.get("createBy")), criteriaBuilder.equal(publishStatus, para.get("publishStatus")));
                Predicate predicate = criteriaBuilder.or(predicate1, predicate2);
                list.add(predicate);

                JPAUtil.like(list, criteriaBuilder, root, "title", para);

                return criteriaBuilder.and(list.toArray(new Predicate[list.size()]));
            }
        };
    }

　　

public static void like(List<Predicate> predicates,CriteriaBuilder cb, Root<?> root, String colmun, Map para) {
        like(predicates,cb,root,colmun,para,colmun);
    }

    public static void like(List<Predicate> predicates,CriteriaBuilder cb, Root<?> root, String colmun, Map para,String paraKey) {
        if(!checkPara(paraKey,para)){
            return;
        }
        try {
            String title = (String) para.get(paraKey);
            if(title.contains("_") || title.contains("%")){
                //注："\"被作为转义字符时必须也被转义
                title = title.replace("\\","\\\\").replace("_","\\_").replace("%","\\%");
                predicates.add(cb.like(root.get(colmun), "%" + title + "%",'\\'));
            }else{
                predicates.add(cb.like(root.get(colmun), "%" + para.get(paraKey) + "%"));
            }
        } catch (Exception e) {
            e.printStackTrace();
            predicates.add(cb.like(root.get(colmun), "%" + para.get(paraKey) + "%"));
        }
    }

　　在此做以记录。

来源：https://www.cnblogs.com/weizhxa/p/12264864.html