logback-android/src/main/java/ch/qos/logback/core/OutputStreamAppender.java
public void setOutputStream(OutputStream outputStream) {
    lock.lock();
    try {
      // close any previously opened output stream
      closeOutputStream();

      this.outputStream = outputStream;
      if (encoder == null) {
        addWarn("Encoder has not been set. Cannot invoke its init method.");
        return;
      }

      encoderInit();
    } finally {
      lock.unlock();
    }
  }
public void setOutputStream(OutputStream outputStream) {
    lock.lock();
    try {
      // close any previously opened output stream
      closeOutputStream();

      this.outputStream = outputStream;
      if (encoder == null) {
        addWarn("Encoder has not been set. Cannot invoke its init method.");
        return;
      }

      encoderInit();
    } finally {
      lock.unlock();
    }
  }
<p>
Sets the @link OutputStream} where the log output will go. The specified
<code>OutputStream</code> must be opened by the user and be writable. The
<code>OutputStream</code> will be closed when the appender instance is
closed.

@param outputStream
An already opened OutputStream.