자바 도구 클래스 - List 를 트 리 구조 로 변환

import java.lang.reflect.Field;import java.lang.reflect.Modifier;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.function.BiConsumer;import java.util.function.Function;import java.util.function.Supplier;import java.util.stream.Collectors;/**

@program: myUtil

@ description: 도구 류 - 트 리 구조 생 성

@author: syf

@create: 2021-06-15 10:38 */

public class TreeModel {

/**
 *       
 */
private Function superColumn;
/**
 *       
 */
private Function column;
/**
 *        
 */
private BiConsumer> children;
/**
 *     
 */
private List list;
/**
 *             
 */
private Supplier decoupling;
/**
 *       
 */
private TreeModel() {
}
/**
 *           
 *
 * @param list                 
 * @param superColumn     (  ::  get  )
 * @param column          (  ::  get  )
 * @param children            (  ::  set  )
 * @return      
 */
public static  TreeModel load(List list, Function superColumn,
                                    Function column, BiConsumer> children) {
    TreeModel treeModel = new TreeModel<>();
    treeModel.setSuperColumn(superColumn)
            .setColumn(column)
            .setChildren(children)
            .setList(list);
    return treeModel;
}
/**
 *       （                   ）
 *
 * @param initValue    
 * @return         
 */
public List getTree(Object initValue) {
    List tree = treeAll(initValue);
    if (tree != null && tree.size() > 0) {
        return tree.stream().filter(ls -> initValue.equals(superColumn.apply(ls))).collect(Collectors.toList());
    }
    return tree;
}
/**
 *       （                  ）
 *
 * @param initValue     
 * @param decoupling       （  ::new）
 * @return         
 */
public List getTree(Object initValue, Supplier decoupling) {
    this.setDecoupling(decoupling);
    return tree(initValue);
}
/**
 *       
 *
 * @param initValue    
 * @return     
 */
private List treeAll(Object initValue) {
    if (list == null || list.size() < 1) {
        return list;
    }
    List collect = list.stream().filter(f -> initValue.equals(superColumn.apply(f))).collect(Collectors.toList());
    if (collect.size() < 1) {
        return null;
    }
    collect.forEach(c -> children.accept(c, treeAll(column.apply(c))));
    return collect;
}
private List tree(Object o) {
    List childrenList = new ArrayList<>();
    if(o == null){
        return childrenList;
    }
    for (T entity : list) {
        if (o.equals(superColumn.apply(entity))) {
            T now = decoupling.get();
            copy(entity, now);
            childrenList.add(now);
        }
    }
    for (T cs : childrenList) {
        children.accept(cs, tree(column.apply(cs)));
    }
    return childrenList;
}
/**
 *  source       target
 * @param source         
 * @param target         
 */
private void copy(T source, T target) {
    if (source == null) {
        throw new NullPointerException("dataSource");
    }
    if (target == null) {
        target = decoupling.get();
    }
    Field[] sourceFields = source.getClass().getDeclaredFields();
    Field[] targetFields =[  ](https://www.gendan5.com/p/2021-06-11/248014.html) target.getClass().getDeclaredFields();
    Map sourceMap = new HashMap<>(sourceFields.length);
    try {
        for (Field field : sourceFields) {
            if (Modifier.isFinal(field.getModifiers())) {
                continue;
            }
            field.setAccessible(true);
            sourceMap.put(field.getName(), field.get(source));
        }
        for (Field field : targetFields) {
            Object o = sourceMap.get(field.getName());
            if (o == null) {
                continue;
            }
            field.setAccessible(true);
            field.set(target, o);
        }
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    }
}
private TreeModel setSuperColumn(Function superColumn) {
    if (superColumn == null) {
        throw new NullPointerException("superColumn");
    }
    this.superColumn = superColumn;
    return this;
}
private TreeModel setColumn(Function column) {
    if (column == null) {
        throw new NullPointerException("column");
    }
    this.column = column;
    return this;
}
private TreeModel setChildren(BiConsumer> children) {
    if (children == null) {
        throw new NullPointerException("children");
    }
    this.children = children;
    return this;
}
private void setList(List list) {
    if (list == null || list.size() < 1) {
        throw new NullPointerException("list");
    }
    this.list = list;
}
private void setDecoupling(Supplier decoupling) {
    if (decoupling == null) {
        throw new NullPointerException("decoupling");
    }
    this.decoupling = decoupling;
}

}