最近的项目中遇到了一个含有大量数据的树结构的展示，不要跟我说什么树都是数据量不大的之类的话。大不大我能控制吗？
我能控制的只是怎么用更好的方法把遇到的问题解决了。
代码都在下面了，基本已经可以说是通用的了，谁有用的话直接复制走，改吧改吧就能用。而却算法我也已经进行了大量的优化。all是树所有节点，in是选中节点，combotreeModel是用来反射的模型，可有可无，不用模型直接用字符串也行。
@RequestMapping(params = "setnornBusiness")
@ResponseBody
public List setPFunction(HttpServletRequest request,
ComboTree comboTree, HttpSession session) {
CriteriaQuery cq = new CriteriaQuery(TreeNornBusiness.class);
cq.addOrder("cmdsort", SortDirection.asc);
cq.eq("isuse", "1");
List treeNornBusinessList = systemService.getListByCriteriaQuery(
cq, false);
List comboTrees;
ComboTreeModel comboTreeModel = new ComboTreeModel("id",
"name", "nornBusinessPid");
//获取已有指令
String nornuserid = String.valueOf(session.getAttribute("nornuserid"));
List cmdtreeList = systemService.findByProperty(NornCmdtreeEntity.class, "nornuserid", nornuserid);
comboTrees = systemService.ComboTree(treeNornBusinessList, comboTreeModel, cmdtreeList);
return comboTrees;
} /**
* 根据模型生成ComboTree JSON
*
* @param all全部对象
* @param in已拥有的对象
* @param comboTreeModel模型
* @return
*/
public List ComboTree(List all, ComboTreeModel comboTreeModel, List in) {
Set inIDs = new HashSet();
if (in != null) {
for (Object o : in) {
if (o != null) {
ReflectHelper reflectHelper = new ReflectHelper(o);
String id = oConvertUtils.getString(reflectHelper.getMethodValue("businessid"));
inIDs.add(id);
}
}
}
List trees = new ArrayList();//顶级节点集合
Set pIds = new HashSet();
Map> pIdMap = new HashMap>();
for (Object obj : all) {
// ComboTree comboTree = new ComboTree();
ComboTree comboTree = myComboTree(obj, comboTreeModel, inIDs);
if (comboTree.getpId() == "") {//如果pid==null则是顶级节点
trees.add(comboTree);
} else {
boolean add = pIds.add(comboTree.getpId());
if (add) {//如果pId添加进去了则说明第一次
List comboTrees = new ArrayList();
comboTrees.add(comboTree);
pIdMap.put(comboTree.getpId(), comboTrees);
} else {//否则这个pId之前就已经被添加过了
List comboTrees = pIdMap.get(comboTree.getpId());
comboTrees.add(comboTree);
pIdMap.put(comboTree.getpId(), comboTrees);
}
}
}
if (trees != null) {
for (ComboTree tree : trees) {
createResultTree(tree, pIdMap);
}
}
return trees;
} /**
* @LiYuKun 2017/7/31 13:50 构建一个节点
* @param obj
* @param comboTreeModel
* @param inIDs
* @return
*/
private ComboTree myComboTree(Object obj, ComboTreeModel comboTreeModel, Set inIDs) {
ComboTree tree = new ComboTree();
Map attributes = new HashMap();
ReflectHelper reflectHelper = new ReflectHelper(obj);
String id = oConvertUtils.getString(reflectHelper.getMethodValue(comboTreeModel.getIdField()));
tree.setId(id);
tree.setpId(oConvertUtils.getString(reflectHelper.getMethodValue(comboTreeModel.getpId())));
tree.setText(oConvertUtils.getString(reflectHelper.getMethodValue(comboTreeModel.getTextField())));
if (comboTreeModel.getSrcField() != null) {
attributes.put("href", oConvertUtils.getString(reflectHelper.getMethodValue(comboTreeModel.getSrcField())));
tree.setAttributes(attributes);
}
if (inIDs == null) {
} else {
if (inIDs.size() > 0) {
boolean add = inIDs.add(id);//为true 添加成功了，则说明该节点没有在被选中；为false则说明已经被选中了
if (!add) {
tree.setChecked(true);
}
}
}
return tree;
}public class ReflectHelper {
private Class cls;
/**
* 传过来的对象
*/
private Object obj;
/**
* 存放get方法
*/
private Hashtable getMethods = null;
/**
* 存放set方法
*/
private Hashtable setMethods = null;
/**
* 定义构造方法 -- 一般来说是个pojo
*
* @param o
* 目标对象
*/
public ReflectHelper(Object o) {
obj = o;
initMethods();
}
/**
*
* @desc 初始化
*/
public void initMethods() {
getMethods = new Hashtable();
setMethods = new Hashtable();
cls = obj.getClass();
Method[] methods = cls.getMethods();
// 定义正则表达式，从方法中过滤出getter / setter 函数.
String gs = "get(\\w+)";
Pattern getM = Pattern.compile(gs);
String ss = "set(\\w+)";
Pattern setM = Pattern.compile(ss);
// 把方法中的"set" 或者 "get" 去掉
String rapl = "$1";
String param;
for (int i = 0; i < methods.length; ++i) {
Method m = methods[i];
String methodName = m.getName();
if (Pattern.matches(gs, methodName)) {
param = getM.matcher(methodName).replaceAll(rapl).toLowerCase();
getMethods.put(param, m);
} else if (Pattern.matches(ss, methodName)) {
param = setM.matcher(methodName).replaceAll(rapl).toLowerCase();
setMethods.put(param, m);
} else {
// org.jeecgframework.core.util.LogUtil.info(methodName + " 不是getter,setter方法！");
}
}
}
/**
*
* @desc 调用set方法
*/
public boolean setMethodValue(String property,Object object) {
Method m = setMethods.get(property.toLowerCase());
if (m != null) {
try {
// 调用目标类的setter函数
m.invoke(obj, object);
return true;
} catch (Exception ex) {
org.jeecgframework.core.util.LogUtil.info("invoke getter on " + property + " error: " + ex.toString());
return false;
}
}
return false;
}
/**
*
* @desc 调用set方法
*/
public Object getMethodValue(String property) {
Object value=null;
Method m = getMethods.get(property.toLowerCase());
if (m != null) {
try {
/**
* 调用obj类的setter函数
*/
value=m.invoke(obj, new Object[] {});
} catch (Exception ex) {
org.jeecgframework.core.util.LogUtil.info("invoke getter on " + property + " error: " + ex.toString());
}
}
return value;
}
} /**
* @param comboTree
* @param pIdMap
* @LiYuKun 2017/7/31 8:13,递归填充树结构,填充完之后即为要返回的数据
*/
private void createResultTree(ComboTree comboTree, Map> pIdMap) {
if (pIdMap.get(comboTree.getId()) != null) {
comboTree.setChildren(pIdMap.get(comboTree.getId()));
if (pIdMap.get(comboTree.getId()) != null) {
for (ComboTree tree : pIdMap.get(comboTree.getId())) {
createResultTree(tree, pIdMap);
}
}
}
}