java - 字符串 Java 代码检查

Question

我想优化Java源代码。我实现了此文件下载代码:

if (!file.exists())
        {
            response.sendError(HttpServletResponse.SC_NOT_FOUND, "No file " + reportPath);
            return;
        }

        if (!file.canWrite())
        {
            response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Can't write in file " + reportPath);
            return;
        }

        if (!file.canRead())
        {
            response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Can't read file " + reportPath);
            return;
        }

如何使其更加紧凑？

Answer 1

您可以交换到 if-else，然后利用方法范围末尾的隐式返回。

public void doThing(Object response) {
  if (!file.exists()) {
    response.sendError(HttpServletResponse.SC_NOT_FOUND, "No file " + reportPath);
  } else if (!file.canWrite()) {
    response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Can't write in file " + reportPath);
  } else if (!file.canRead()) {
    response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Can't read file " + reportPath);
  } else {
    doStuff();
  }
  // Implicit return
}