selenium中ByChained方法

ByChained是一个存储By数组的类，和ByAll的区别就是ByChained能够把子元素也存储起来。

ByChained应该也是可以实现远程测试的。

import org.openqa.selenium.By;
import org.openqa.selenium.NoSuchElementException;
import org.openqa.selenium.SearchContext;
import org.openqa.selenium.WebElement;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class ByChained extends By implements Serializable {

  private static final long serialVersionUID = 1563769051170172451L;

  private By[] bys;

  public ByChained(By... bys) {
    this.bys = bys;
  }

  @Override
  public WebElement findElement(SearchContext context) {
    List<WebElement> elements = findElements(context);
    if (elements.isEmpty())
      throw new NoSuchElementException("Cannot locate an element using " + toString());
    return elements.get(0);
  }

  @Override
  public List<WebElement> findElements(SearchContext context) {
    if (bys.length == 0) {
      return new ArrayList<>();
    }

    List<WebElement> elems = null;
    for (By by : bys) {
      List<WebElement> newElems = new ArrayList<>();

      if (elems == null) {
        newElems.addAll(by.findElements(context));
      } else {
        for (WebElement elem : elems) {
          newElems.addAll(elem.findElements(by));
        }
      }
      elems = newElems;
    }

    return elems;
  }

  @Override
  public String toString() {
    StringBuilder stringBuilder = new StringBuilder("By.chained(");
    stringBuilder.append("{");

    boolean first = true;
    for (By by : bys) {
      stringBuilder.append((first ? "" : ",")).append(by);
      first = false;
    }
    stringBuilder.append("})");
    return stringBuilder.toString();
  }

}