Question

我有以下代码。我得到“避免在条件语句中使用文字”。在第5行的PMD中发出警告。

List<Object> listObj = getData();
 if (listObj.isEmpty()) {
      throw new NoEntity("No entity found for given Device.");
 }
 if (listObj.size() > 1) {
      throw new MultiEntity(
          "Multiple entity record found for given Device.");
 }

我更喜欢不将全局静态final int变量赋值为1并在if条件中使用它。还有其他任何解决方案吗？

Answer 1

最好的解决方案是使用//Controlling the back stack when the user selects the soft back button in the toolbar @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: if (fragmentManager.getBackStackEntryCount() == 0) { super.onBackPressed(); overridePendingTransition(R.anim.no_change, R.anim.slide_down); } else { if(!BaseFragment.handleBackPressed(getSupportFragmentManager())){ super.onBackPressed(); Fragment fragment = fragmentManager.getFragments() .get(fragmentManager.getBackStackEntryCount()); fragment.onResume(); //Make sure the fragment that is currently at the top of the stack calls its onResume method } } return true; } return super.onOptionsItemSelected(item); } //Controlling the back stack when the user selects the "hardware" back button @Override public void onBackPressed() { if (fragmentManager.getBackStackEntryCount() == 0) { super.onBackPressed(); overridePendingTransition(R.anim.no_change, R.anim.slide_down); } else { if(!BaseFragment.handleBackPressed(getSupportFragmentManager())){ super.onBackPressed(); Fragment fragment = fragmentManager.getFragments() .get(fragmentManager.getBackStackEntryCount()); fragment.onResume(); //Make sure the fragment that is currently at the top of the stack calls its onResume method } } }来抑制警告是如此简单的情况。

但是，对于您的示例，我有一个解决方案。

使用Guava的Iterables：

@SuppressWarnings("PMD.AvoidLiteralsInIfCondition")

Answer 2

如果您使用的是Apache Commons Lang，它可以在NumberUtils https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/math/NumberUtils.html#INTEGER_ONE中找到

Answer 3

您可以在前一行中添加分配以记录条件。它将提高可读性，同时使警告消失。

boolean multiEntityDevice = listObj.size() > 1;
if (multiEntityDevice) {
  throw new MultiEntity(
      "Multiple entity record found for given Device.");
}

Answer 4

您可以将PMD配置中的rule definition修改为1作为MagicNumber。我看不出任何理由为何1不应成为规则本身的默认值之一。


<rule ref="category/java/errorprone.xml/AvoidLiteralsInIfCondition">
    <properties>
        <property name="ignoreMagicNumbers" value="-1,0,1" />
        <property name="ignoreExpressions" value="true" />
    </properties>
</rule>

如果您不想自己修改规则配置，可以对PMD on Github提出疑问。

PMD：避免在条件语句中使用文字

4 个答案: