举例部门级别
//节点对象类 package com.test; import java.util.List; /** * ClassName: TestMode * @Description: 测试对象 */ public class TestMode { /** 节点id */ private String id; /** 节点名称 */ private String name; /** 父节点id */ private String parentId; /** 节点下的子节点 */ private List<TestMode> children; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getParentId() { return parentId; } public void setParentId(String parentId) { this.parentId = parentId; } public List<TestMode> getChildren() { return children; } public void setChildren(List<TestMode> children) { this.children = children; } @Override public String toString() { return "{"+"id=" + id + ", name=" + name + ", parentId=" + parentId + ", children=" + children+"}"; } } 测试类
package com.test; import java.util.ArrayList; import java.util.List; /** * @Description: 转化List为树形结构 */ public class ListToTreeUtil { public static void main(String[] args) { List<TestMode> list = new ArrayList<TestMode>(); TestMode testMode1 = new TestMode(); testMode1.setId("-1"); testMode1.setName("父节点"); testMode1.setParentId("0");//其实-1节点没有父节点，只是为了方便 TestMode testMode2 = new TestMode(); testMode2.setId("1"); testMode2.setName("第一级节点1"); testMode2.setParentId("-1"); TestMode testMode3 = new TestMode(); testMode3.setId("2"); testMode3.setName("第一级节点2"); testMode3.setParentId("-1"); TestMode testMode4 = new TestMode(); testMode4.setId("11"); testMode4.setName("第二级节点11"); testMode4.setParentId("1"); TestMode testMode5 = new TestMode(); testMode5.setId("111"); testMode5.setName("第三级节点111"); testMode5.setParentId("11"); TestMode testMode6 = new TestMode(); testMode6.setId("21"); testMode6.setName("第二级级节点21"); testMode6.setParentId("2"); list.add(testMode1); list.add(testMode2); list.add(testMode3); list.add(testMode4); list.add(testMode5); list.add(testMode6); System.out.println("处理前的数据格式:"+ list.toString()); list = getDeptTree(list,"0"); System.out.println("处理后的数据格式:"+ list.toString()); } public static List<TestMode> getDeptTree(List<TestMode> list,String pid){ List<TestMode> result = new ArrayList<TestMode>(); List<TestMode> temp = new ArrayList<TestMode>(); for(TestMode entity : list){ if(entity.getParentId().equals(pid)){ TestMode deptScopeMode = new TestMode(); deptScopeMode.setId(entity.getId()); deptScopeMode.setName(entity.getName()); deptScopeMode.setParentId(entity.getParentId()); temp = getDeptTree(list,entity.getId()); if(temp.size() > 0){ deptScopeMode.setChildren(temp); } result.add(deptScopeMode); } } return result; } } 处理签的数据格式：
[{ id = -1, name = 父节点, parentId = 0, children = null }, { id = 1, name = 第一级节点1, parentId = -1, children = null }, { id = 2, name = 第一级节点2, parentId = -1, children = null }, { id = 11, name = 第二级节点11, parentId = 1, children = null }, { id = 111, name = 第三级节点111, parentId = 11, children = null }, { id = 21, name = 第二级级节点21, parentId = 2, children = null }] 处理后的数据格式：
[{ id = -1, name = 父节点, parentId = 0, children = [{ id = 1, name = 第一级节点1, parentId = -1, children = [{ id = 11, name = 第二级节点11, parentId = 1, children = [{ id = 111, name = 第三级节点111, parentId = 11, children = null }] }] }, { id = 2, name = 第一级节点2, parentId = -1, children = [{ id = 21, name = 第二级级节点21, parentId = 2, children = null }] }] }] 文章来源: java-树形结构的list，转化为树形结构