java - 使用迭代器对列表进行排序

Question

我需要先按行号，然后按列号对对象列表进行排序。每当用户 set(row, col, x) ，放入rowColSeq在某个位置上。例如，

board.set(1, 1, "aa");
board.set(1, 3, "aa");
board.set(0, 1, "B");
board.set(0, 2, "B");
board.set(1, 0, "aa"); 

列表应按以下方式排序:

[0,1,"B"], [0,2,"B"], [1,0,"aa"], [1,1,"aa"], [1,3,"aa"] 

但是我的代码给了我无限循环。 smb 可以告诉我我用我的代码做了什么吗？

假设列表不为空!

  LinkedList<RowColElem<T>> rowColElems; //contains some info

 private void sortedRowColSeq(int row, int col, T x){
      RowColElem<T> object = new RowColElem<T>(row, col, x);
      ListIterator<RowColElem<T>> iter = rowColSeq.listIterator();
      while(iter.hasNext()){
          RowColElem<T> inListObject = iter.next();
          if(object.getRow() < inListObject.getRow()){
              iter.previous();
              iter.add(object);
          }
          else if(object.getRow() == inListObject.getRow()){
              if(object.getCol() < inListObject.getCol()){
                  iter.previous();
                  iter.add(object);
              }
              else{
                  iter.add(object);
              }
          }
          else{
              iter.add(object);
          }
      }
  }

<强> RowColElem<T>类

public class RowColElem<T>{
  private int row;
  private int col;
  private T elem;

  // Create a RowColElem with the parameter parts
  public RowColElem(int r, int c, T e){
    this.row = r;
    this.col = c;
    this.elem = e;
  }

  // Return the row
  public int getRow(){
    return this.row;
  }

  // Return the column
  public int getCol(){
    return this.col;
  }

  // Return the element
  public T getElem(){
    return this.elem;
  }

  // Return a pretty string version of the triple formated as
  // (row,col,elem)
  public String toString(){
    return String.format("(%d,%d,%s)",row,col,elem);
  }

  @SuppressWarnings("unchecked")
  // Perform a deep equality check between this RowColElem and another
  // object
  public boolean equals(Object other){
    if(other == null || !(other instanceof RowColElem)){
      return false;
    }
    RowColElem<T> that = (RowColElem<T>) other;
    return
      this.row == that.row &&
      this.col == that.col &&
      this.elem.equals(that.elem);
  }
}

Answer 1

您的基本问题是您编写了排序代码。解决方案是单行:

Collections.sort(Comparators.comparing(RowColElem::getRow)
  .andThen(RowColElem::getCol));