java 递归查询某个父节点下的所有叶子节点

id	name	       parent_id
1	qq	       null	
2	qqw	       null	
3	www	       null
4	www	        1	
5	wwwf	          1	
6	dsf	        1	
7	asdfasf	          1	
8	dasfdasf	    2	
9	df	        2	
10	dfd      	    3 
11	fdasf	          3
12	adfasf	          3
13	adsfas	          3	
14	ddd	        4	
15	dddd	          4	
16	dddffd	          6	
17	dfafa	          6	
18	asdfasf	          6	

public List<DocumentTypeModel> getTreeMenuList(List<DocumentTypeModel> domainList ,String pid) {
    //加入它本身
    DocumentTypeModel model = new DocumentTypeModel();
    model.setId(Integer.parseInt(pid));
    domainList.add(model);
    //加入子集
    DocumentTypeDomain domainType = new DocumentTypeDomain();
    domainType.setParentId(Integer.parseInt(pid));
    List<DocumentTypeDomain> list = documentTypeDao.findListByParentId(domainType);
        for(DocumentTypeDomain type : list) {
            getTreeMenuList(domainList,String.valueOf(type.getId()));
        }
    return domainList;
}

public class DocumentTypeModel implements Serializable {
    private Integer id;  //id


    private String name;  //类型名称


    private Integer parentId; //父id
	
	
	 public Integer getId() {
        return id;
    }


    public void setId(Integer id) {
        this.id = id;
    }


    public String getName() {
        return name;
    }


    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }


    public Integer getParentId() {
        return parentId;
    }


    public void setParentId(Integer parentId) {
        this.parentId = parentId;
    }
}




public class DocumentTypeDomain implements Serializable {
    private Integer id;


    private String name;


    private Integer parentId;


	
	 public Integer getId() {
        return id;
    }


    public void setId(Integer id) {
        this.id = id;
    }


    public String getName() {
        return name;
    }


    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }


    public Integer getParentId() {
        return parentId;
    }


    public void setParentId(Integer parentId) {
        this.parentId = parentId;
    }
}