递归查询树形菜单

菜单表设计，一级菜单parentId都是0，二级菜单直接是插入对应得父级id即可

public List<TResource> queryResource() {
    //查询所有得一级菜单
    Example example = new Example(TResource.class);
    Example.Criteria resourceCriteria = example.createCriteria();
    resourceCriteria.andEqualTo("parentId", 0L);
    example.orderBy("resOrder").asc();
    List<TResource> parentList =  resourceMapper.selectByExample(example);
    for(TResource tResource : parentList){
        tResource.setChildren(childList(tResource.getId()));
    }
    return parentList;
}

/**
 * 查询子菜单
 * @param parentId
 * @return
 */
public List<TResource> childList(Long parentId){
    Example example = new Example(TResource.class);
    Example.Criteria resourceCriteria = example.createCriteria();
    resourceCriteria.andEqualTo("parentId", parentId);
    example.orderBy("resOrder").asc();
    List<TResource> childList = resourceMapper.selectByExample(example);
　　
    for(TResource tResource : childList){
　　　　　//递归查询子菜单下面是否还存在子菜单
        tResource.setChildren(childList(tResource.getId()));
    }
    return childList;
}

这里我用得是tk-mybatis，和mybatis-plus是差不多得功能，都是对mybaits得进一步封装，不需要我们去手动得写单表得sql语句。