When a method is called that returns data read from some data source, that data should be stored rather than thrown away. Any other course of action is surely a bug.


This rule raises an issue when the return value of any of the following is ignored or merely null-checked: ``++BufferedReader.readLine()++``, ``++Reader.read()++``, and these methods in any child classes.

== Noncompliant Code Example

----
public void doSomethingWithFile(String fileName) {
  BufferedReader buffReader = null;
  try {
    buffReader = new BufferedReader(new FileReader(fileName));
    while (buffReader.readLine() != null) { // Noncompliant
      // ...
    }
  } catch (IOException e) {
    // ...
  }
}
----

== Compliant Solution

----
public void doSomethingWithFile(String fileName) {
  BufferedReader buffReader = null;
  try {
    buffReader = new BufferedReader(new FileReader(fileName));
    String line = null;
    while ((line = buffReader.readLine()) != null) {
      // ...
    }
  } catch (IOException e) {
    // ...
  }
}
----