JAVA根据数据库表内容生产树结构JSON数据

JAVA根据数据库表内容生产树结构JSON数据2017-01-08 博客园 kangxu1、利用场景

组织机构树，通常会有组织机构表，其中有code（代码）,pcode（上级代码）,name（组织名称）等字段

2、构造数据（以下数据并不是组织机构数据，而纯属本人胡编乱造的数据）

 1 List<Tree<Test>> trees = new ArrayList<Tree<Test>>（）; 2 tests.add（new Test（"0", "", "关于本人"））; 3 tests.add（new Test（"1", "0", "技术学习"））; 4 tests.add（new Test（"2", "0", "兴趣"））; 5 tests.add（new Test（"3", "1", "JAVA"））; 6 tests.add（new Test（"4", "1", "oracle"））; 7 tests.add（new Test（"5", "1", "spring"））; 8 tests.add（new Test（"6", "1", "springmvc"））; 9 tests.add（new Test（"7", "1", "fastdfs"））;10 tests.add（new Test（"8", "1", "linux"））;11 tests.add（new Test（"9", "2", "骑行"））;12 tests.add（new Test（"10", "2", "吃喝玩乐"））;13 tests.add（new Test（"11", "2", "学习"））;14 tests.add（new Test（"12", "3", "String"））;15 tests.add（new Test（"13", "4", "sql"））;16 tests.add（new Test（"14", "5", "ioc"））;17 tests.add（new Test（"15", "5", "aop"））;18 tests.add（new Test（"16", "1", "等等"））;19 tests.add（new Test（"17", "2", "等等"））;20 tests.add（new Test（"18", "3", "等等"））;21 tests.add（new Test（"19", "4", "等等"））;22 tests.add（new Test（"20", "5", "等等"））;

3、源码

Tree.java

1 package pers.kangxu.datautils.bean.tree;2 3 import java.util.ArrayList;4 import java.util.List;5 import java.util.Map;6 7 import com.alibaba.fastjson.JSON;8 9 /** 10* tree TODO <br> 11*12* @author kangxu2 2017-1-7 13*14*/ 15 public class Tree<T> { 16 /** 17* 节点ID 18*/ 19 private String id; 20 /** 21* 显示节点文本 22*/ 23 private String text; 24 /** 25* 节点状态，open closed 26*/ 27 private String state = "open"; 28 /** 29* 节点是否被选中 true false 30*/ 31 private boolean checked = false; 32 /** 33* 节点属性 34*/ 35 private List<Map<String, Object>> attributes; 36 /** 37* 节点的子节点 38*/ 39 private List<Tree<T>> children = new ArrayList<Tree<T>>（）; 4041 /** 42* 父ID 43*/ 44 private String parentId; 45 /** 46* 是否有父节点 47*/ 48 private boolean isParent = false; 49 /** 50* 是否有子节点 51*/ 52 private boolean isChildren = false; 5354 public String getId（） { 55 return id; 56 } 5758 public void setId（String id） { 59 this.id = id; 60 } 6162 public String getText（） { 63 return text; 64 } 6566 public void setText（String text） { 67 this.text = text; 68 } 6970 public String getState（） { 71 return state; 72 } 7374 public void setState（String state） { 75 this.state = state; 76 } 7778 public boolean isChecked（） { 79 return checked; 80 } 8182 public void setChecked（boolean checked） { 83 this.checked = checked; 84 } 8586 public List<Map<String, Object>> getAttributes（） { 87 return attributes; 88 } 8990 public void setAttributes（List<Map<String, Object>> attributes） { 91 this.attributes = attributes; 92 } 9394 public List<Tree<T>> getChildren（） { 95 return children; 96 } 9798 public void setChildren（List<Tree<T>> children） { 99 this.children = children;100 }101 102 public boolean isParent（） {103 return isParent;104 }105 106 public void setParent（boolean isParent） {107 this.isParent = isParent;108 }109 110 public boolean isChildren（） {111 return isChildren;112 }113 114 public void setChildren（boolean isChildren） {115 this.isChildren = isChildren;116 }117 118 public String getParentId（） {119 return parentId;120 }121 122 public void setParentId（String parentId） {123 this.parentId = parentId;124 }125 126 public Tree（String id, String text, String state, boolean checked,127 List<Map<String, Object>> attributes, List<Tree<T>> children,128 boolean isParent, boolean isChildren, String parentID） {129 super（）;130 this.id = id;131 this.text = text;132 this.state = state;133 this.checked = checked;134 this.attributes = attributes;135 this.children = children;136 this.isParent = isParent;137 this.isChildren = isChildren;138 this.parentId = parentID;139 }140 141 public Tree（） {142 super（）;143 }144 145 @Override146 public String toString（） {147 148 return JSON.toJSONString（this）;149 }150 151 }

BuildTree.java

 1 package pers.kangxu.datautils.common.tree; 23 import java.util.ArrayList; 4 import java.util.List; 56 import pers.kangxu.datautils.bean.tree.Tree; 78 /** 9* 构建tree10* TODO11* <br>12* @author kangxu2 2017-1-713*14*/15 public class BuildTree {16 17 /**18* 19* TODO20* <br>21* @author kangxu2 2017-1-722*23* @param nodes24* @return25*/26 public static <T> Tree<T> build（List<Tree<T>> nodes） {27 28 if（nodes == null）{29 return null;30 }31 List<Tree<T>> topNodes = new ArrayList<Tree<T>>（）;32 33 for （Tree<T> children : nodes） {34 35 String pid = children.getParentId（）;36 if （pid == null || "".equals（pid）） {37 topNodes.add（children）;38 39 continue;40 }41 42 for （Tree<T> parent : nodes） {43 String id = parent.getId（）;44 if （id ！= null && id.equals（pid）） {45 parent.getChildren（）.add（children）;46 children.setParent（true）;47 parent.setChildren（true）;48 49 continue;50 }51 }52 53 }54 55 Tree<T> root = new Tree<T>（）;56 if （topNodes.size（） == 0） {57 root = topNodes.get（0）;58 } else {59 root.setId（"-1"）;60 root.setParentId（""）;61 root.setParent（false）;62 root.setChildren（true）;63 root.setChecked（true）;64 root.setChildren（topNodes）;65 root.setText（"顶级节点"）;66 67 }68 69 return root;70 }71 72 }

BuildTreeTester.java

 1 package pers.kangxu.datautils.test; 23 import java.util.ArrayList; 4 import java.util.List; 56 import pers.kangxu.datautils.bean.tree.Tree; 7 import pers.kangxu.datautils.common.tree.BuildTree; 89 public class BuildTreeTester {10 11 public static void main（String[] args） {12 13 14 List<Tree<Test>> trees = new ArrayList<Tree<Test>>（）;15 List<Test> tests = new ArrayList<Test>（）;16 tests.add（new Test（"0", "", "关于本人"））;17 tests.add（new Test（"1", "0", "技术学习"））;18 tests.add（new Test（"2", "0", "兴趣"））;19 tests.add（new Test（"3", "1", "JAVA"））;20 tests.add（new Test（"4", "1", "oracle"））;21 tests.add（new Test（"5", "1", "spring"））;22 tests.add（new Test（"6", "1", "springmvc"））;23 tests.add（new Test（"7", "1", "fastdfs"））;24 tests.add（new Test（"8", "1", "linux"））;25 tests.add（new Test（"9", "2", "骑行"））;26 tests.add（new Test（"10", "2", "吃喝玩乐"））;27 tests.add（new Test（"11", "2", "学习"））;28 tests.add（new Test（"12", "3", "String"））;29 tests.add（new Test（"13", "4", "sql"））;30 tests.add（new Test（"14", "5", "ioc"））;31 tests.add（new Test（"15", "5", "aop"））;32 tests.add（new Test（"16", "1", "等等"））;33 tests.add（new Test（"17", "2", "等等"））;34 tests.add（new Test（"18", "3", "等等"））;35 tests.add（new Test（"19", "4", "等等"））;36 tests.add（new Test（"20", "5", "等等"））;37 38 for （Test test : tests） {39 Tree<Test> tree = new Tree<Test>（）;40 tree.setId（test.getId（））;41 tree.setParentId（test.getPid（））;42 tree.setText（test.getText（））;43 44 trees.add（tree）;45 }46 47 Tree<Test> t = BuildTree.build（trees）;48 System.out.println（t）;49 }50 }51 52 class Test {53 54 private String id;55 private String pid;56 private String text;57 58 public String getId（） {59 return id;60 }61 62 public void setId（String id） {63 this.id = id;64 }65 66 public String getPid（） {67 return pid;68 }69 70 public void setPid（String pid） {71 this.pid = pid;72 }73 74 public String getText（） {75 return text;76 }77 78 public void setText（String text） {79 this.text = text;80 }81 82 public Test（String id, String pid, String text） {83 super（）;84 this.id = id;85 this.pid = pid;86 this.text = text;87 }88 89 public Test（） {90 super（）;91 }92 93 @Override94 public String toString（） {95 return "Test [id=" + id + ", pid=" + pid + ", text=" + text + "]";96 }97 98 }

4、运行结果

JSON数据：

{"checked": true,"children": [{"checked": false,"children": [{"checked": false,"children": [{"checked": false,"children": [{"checked": false,"children": [],"id": "12","parent": true,"parentId": "3","state": "open","text": "String"},{"checked": false,"children": [],"id": "18","parent": true,"parentId": "3","state": "open","text": "等等"}],"id": "3","parent": true,"parentId": "1","state": "open","text": "JAVA"},{"checked": false,"children": [{"checked": false,"children": [],"id": "13","parent": true,"parentId": "4","state": "open","text": "sql"},{"checked": false,"children": [],"id": "19","parent": true,"parentId": "4","state": "open","text": "等等"}],"id": "4","parent": true,"parentId": "1","state": "open","text": "oracle"},{"checked": false,"children": [{"checked": false,"children": [],"id": "14","parent": true,"parentId": "5","state": "open","text": "ioc"},{"checked": false,"children": [],"id": "15","parent": true,"parentId": "5","state": "open","text": "aop"},{"checked": false,"children": [],"id": "20","parent": true,"parentId": "5","state": "open","text": "等等"}],"id": "5","parent": true,"parentId": "1","state": "open","text": "spring"},{"checked": false,"children": [],"id": "6","parent": true,"parentId": "1","state": "open","text": "springmvc"},{"checked": false,"children": [],"id": "7","parent": true,"parentId": "1","state": "open","text": "fastdfs"},{"checked": false,"children": [],"id": "8","parent": true,"parentId": "1","state": "open","text": "linux"},{"checked": false,"children": [],"id": "16","parent": true,"parentId": "1","state": "open","text": "等等"}],"id": "1","parent": true,"parentId": "0","state": "open","text": "技术学习"},{"checked": false,"children": [{"checked": false,"children": [],"id": "9","parent": true,"parentId": "2","state": "open","text": "骑行"},{"checked": false,"children": [],"id": "10","parent": true,"parentId": "2","state": "open","text": "吃喝玩乐"},{"checked": false,"children": [],"id": "11","parent": true,"parentId": "2","state": "open","text": "学习"},{"checked": false,"children": [],"id": "17","parent": true,"parentId": "2","state": "open","text": "等等"}],"id": "2","parent": true,"parentId": "0","state": "open","text": "兴趣"}],"id": "0","parent": false,"parentId": "","state": "open","text": "关于本人"}],"id": "-1","parent": false,"parentId": "","state": "open","text": "顶级节点"}

学习无止尽，代码我疯狂

原文：