java - 这是 switch case 的正确使用方式吗

Question

我有一个开关盒，里面有四个重复代码(用于箭头键，但还有更多其他场景)，唯一的区别是 ArrowDown、ArrowUp、ArrowLeft 和 ArrowRight。下面是代码片段:

    switch (peformAction) {
    case "ArrowDown":
        CommonFunctions.silentWait(1);
        actionToE.moveToElement(currentObject).perform();

        if (CommonFunctions.isElementDisplayed(currentObject)) {
            if (CommonFunctions.isElementEnabled(currentObject)) {
                if (!actionPar.isEmpty()) {
                    int intActionPar = Integer.parseInt(actionPar);
                    for (int i = 0; i < intActionPar; i++) {
                        currentObject.sendKeys(Keys.ARROW_DOWN);
                    }
                } else {
                    currentObject.sendKeys(Keys.ARROW_DOWN);
                }
                isActionSuccess = true;
            }
        }

        break;


    case "ArrowLeft":
        CommonFunctions.silentWait(1);
        actionToE.moveToElement(currentObject).perform();

        if (CommonFunctions.isElementDisplayed(currentObject)) {
            if (CommonFunctions.isElementEnabled(currentObject)) {
                if (!actionPar.isEmpty()) {
                    int intActionPar = Integer.parseInt(actionPar);
                    for (int i = 0; i < intActionPar; i++) {
                        currentObject.sendKeys(Keys.ARROW_LEFT);
                    }
                } else {
                    currentObject.sendKeys(Keys.ARROW_LEFT);
                }
                isActionSuccess = true;
            }
        }

        break;

问题:1.)如何改进这段代码(建议)？2.) 是否建议对每个案例都进行 try catch ？

Answer 1

您重复了太多代码。您应该遵循DRY principle ，即不要重复自己。

有两种方法:

• 使用switch为变量分配不同的值，然后在switch block 后使用通用代码。

  Keys key;
  switch (performAction) {
      case "ArrowDown":
          key = Keys.ARROW_DOWN;
          break;
      case "ArrowLeft":
          key = Keys.ARROW_LEFT;
          break;
      ...
      default:
          throw new IllegalArgumentException("Unknown action: " + performAction);
  }
  
  CommonFunctions.silentWait(1);
  actionToE.moveToElement(currentObject).perform();
  
  if (CommonFunctions.isElementDisplayed(currentObject)) {
      if (CommonFunctions.isElementEnabled(currentObject)) {
          if (!actionPar.isEmpty()) {
              int intActionPar = Integer.parseInt(actionPar);
              for (int i = 0; i < intActionPar; i++) {
                  currentObject.sendKeys(key);
              }
          } else {
              currentObject.sendKeys(key);
          }
          isActionSuccess = true;
      }
  }
  

• 将公共(public)代码移至方法中。

  switch (performAction) {
      case "ArrowDown":
          isActionSuccess = performAction(Keys.ARROW_DOWN, currentObject);
          break;
      case "ArrowLeft":
          isActionSuccess = performAction(Keys.ARROW_LEFT, currentObject);
          break;
      ...
  }
  

  private boolean performAction(Keys key, Xxx currentObject) {
      CommonFunctions.silentWait(1);
      actionToE.moveToElement(currentObject).perform();
  
      if (CommonFunctions.isElementDisplayed(currentObject)) {
          if (CommonFunctions.isElementEnabled(currentObject)) {
              if (!actionPar.isEmpty()) {
                  int intActionPar = Integer.parseInt(actionPar);
                  for (int i = 0; i < intActionPar; i++) {
                      currentObject.sendKeys(keys);
                  }
              } else {
                  currentObject.sendKeys(keys);
              }
              return true;
          }
      }
      return false;
  }