Coding.net 自動分析Android代碼錯誤集合

一. 註釋代碼不應該保留而應該使用版本控制工具查找.

二. 使用System.exit()會造成應用重啓,因爲操作系統會以爲是不正常退出.

三. 各種Stream應該正確的關掉.

模板爲:

private void readTheFile() throws IOException {
  Path path = Paths.get(this.fileName);
  BufferedReader reader = Files.newBufferedReader(path, this.charset)) {
  // ...
  reader.close();  // Noncompliant
}

private void doSomething() {
  OutputStream stream = null;
  try {
    for (String property : propertyList) {
      stream = new FileOutputStream("myfile.txt");  // Noncompliant
      // ...
    }
  } catch (Exception e) {
    // ...
  } finally {
    stream.close();  // Multiple streams were opened. Only the last is closed.
  }
}

四. 一些多次使用的字符串應該寫爲靜態變量防止出錯

錯誤寫法爲:

With the default threshold of 3:

public void run() {
  prepare("action1");                              // Noncompliant - "action1" is duplicated 3 times
  execute("action1");
  release("action1");
}

@SuppressWarning("all")                            // Compliant - annotations are excluded
private void method1() { /* ... */ }
@SuppressWarning("all")
private void method2() { /* ... */ }

public String method3(String a) {
  System.out.println("'" + a + "'");               // Compliant - literal "'" has less than 5 characters and is excluded
  return "";                                       // Compliant - literal "" has less than 5 characters and is excluded
}

正確寫法爲:

private static final String ACTION_1 = "action1";  // Compliant

public void run() {
  prepare(ACTION_1);                               // Compliant
  execute(ACTION_1);
  release(ACTION_1);
}

五. 深度嵌套的”if”,”for”,”while”,”switch”,”try”不推薦使用.

比如:

if (condition1) {                  // Compliant - depth = 1
  /* ... */
  if (condition2) {                // Compliant - depth = 2
    /* ... */
    for(int i = 0; i < 10; i++) {  // Compliant - depth = 3, not exceeding the limit
      /* ... */
      if (condition4) {            // Noncompliant - depth = 4
        if (condition5) {          // Depth = 5, exceeding the limit, but issues are only reported on depth = 4
          /* ... */
        }
        return;
      }
    }
  }
}

六. 函數的認知複雜度過高.

每個if +1每個判斷+1等等,相關文檔

七. 未完待續