树形结构业务模型实践
业务场景
# 数据库表结构
TREE表：
ID P_CODE CODE NAME
1 null 001 1级1
2 null 002 1级2
3 null 003 1级3
4 001 001001 2级1
5 002 002001 2级2
6 002 002002 2级3
7 003 003001 2级4
8 003001 003001001 3级1
9 003001001 003001001001 4级1
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# Mybatis
treeMapper.xml：
<mapper ...>
<select id="list" ...>
SELECT * FROM TREE
</select>
</mapper>
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# Java
Node:
public class Node {
private Long id;
private String pCode;
private String code;
private String name;
private List<Node> children;
}
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TreeMapper：
public interface TreeMapper {
List<Node> list();
}
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TreeService:
@Service
public class TreeService {
@Autowired
private TreeMapper treeMapper;
public List<Node> getTree() {
List<Node> list = treeMapper.list();
return getFatherNode(list);
}
private List<Node> getFatherNode(List<Node> treesList) {
List<Node> newTrees = new ArrayList<>();
for (Node node : treesList) {
if (StringUtils.isEmpty(node.getPCode())) {//如果pCode为空，则该节点为父节点
//递归获取父节点下的子节点
node.setChildren(getChildrenNode(node.getCode(), treesList));
newTrees.add(node);
}
}
return newTrees;
}
private List<Node> getChildrenNode(String pCode, List<Node> treesList) {
List<Node> newTrees = new ArrayList<>();
for (Node node : treesList) {
if (StringUtils.isEmpty(node.getPCode())) continue;
if (node.getPCode().equals(pCode)) {
//递归获取子节点下的子节点，即设置树控件中的children
node.setChildren(getChildrenNode(node.getCode(), treesList));
newTrees.add(node);
}
}
return newTrees;
}
}
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参考：
https://www.cnblogs.com/WHqingwei/p/5852657.html (opens new window)
https://www.cnblogs.com/lwenbo/archive/2012/12/19/2824959.html (opens new window)