63 lines
2.3 KiB
Java
63 lines
2.3 KiB
Java
|
import com.alibaba.fastjson.JSON;
|
||
|
|
import com.google.common.collect.Lists;
|
||
|
|
import org.apache.commons.collections.CollectionUtils;
|
||
|
|
|
||
|
|
import java.io.File;
|
||
|
|
import java.io.FileInputStream;
|
||
|
|
import java.io.IOException;
|
||
|
|
import java.util.ArrayList;
|
||
|
|
import java.util.List;
|
||
|
|
import java.util.Objects;
|
||
|
|
import java.util.stream.Collectors;
|
||
|
|
|
||
|
|
public class Main {
|
||
|
|
public static void main(String[] args) throws IOException {
|
||
|
|
String path = ClassLoader.getSystemClassLoader().getResource("data.json").getPath();
|
||
|
|
String s = readToString(path).trim();
|
||
|
|
List<Type> types = JSON.parseArray(s, Type.class);
|
||
|
|
List<Type> types1 = builldTree(types);
|
||
|
|
// 如何取值 id为 842362469438455808 的所有父id需要保持顺序
|
||
|
|
System.out.println(types1);
|
||
|
|
}
|
||
|
|
public static List<Type> builldTree(List<Type> list){
|
||
|
|
ArrayList<Type> tree = Lists.newArrayList();
|
||
|
|
if(CollectionUtils.isNotEmpty(list)){
|
||
|
|
// 添加父节点
|
||
|
|
tree.addAll(
|
||
|
|
list.stream()
|
||
|
|
.filter(Objects::nonNull)
|
||
|
|
.filter(type -> type.getParentId() != null)
|
||
|
|
.filter(type -> type.getParentId() == 0L)
|
||
|
|
.collect(Collectors.toList())
|
||
|
|
);
|
||
|
|
// 添加子节点
|
||
|
|
tree.parallelStream().forEach(t -> {
|
||
|
|
t.setChildList(setChildList(t.getId(),list));
|
||
|
|
});
|
||
|
|
}
|
||
|
|
return tree;
|
||
|
|
}
|
||
|
|
private static List<Type> setChildList(Long id,List<Type> list){
|
||
|
|
List<Type> child = list.stream().filter(t -> Objects.equals(id, t.getParentId())).collect(Collectors.toList());
|
||
|
|
if(CollectionUtils.isEmpty(child)){
|
||
|
|
return child;
|
||
|
|
}
|
||
|
|
child.parallelStream().forEach(t -> t.setChildList(setChildList(t.getId(),list)));
|
||
|
|
return child;
|
||
|
|
}
|
||
|
|
public static String readToString(String fileName) {
|
||
|
|
String encoding = "UTF-8";
|
||
|
|
File file = new File(fileName);
|
||
|
|
Long filelength = file.length();
|
||
|
|
byte[] filecontent = new byte[filelength.intValue()];
|
||
|
|
try {
|
||
|
|
FileInputStream in = new FileInputStream(file);
|
||
|
|
in.read(filecontent);
|
||
|
|
return new String(filecontent, encoding);
|
||
|
|
} catch (Exception e) {
|
||
|
|
e.printStackTrace();
|
||
|
|
return null;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|