重复的字符串文本是应该重构的易错点，因为每个点都要注意每个更新。 常量可以引用很多地方，可以在一个地方进行更新。

如下代码：

public void run() {
  prepare("action1");                              // Non-Compliant - "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
}

应该重构为：

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

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