最后阻止在 Oracle 的 JAVA 存储过程中不起作用

Question

当我编译下面的代码时，它显示错误"找不到符号变量"但是如果我在 finally 块中注释代码，我就能成功编译。

请指教。

public static int writeFile (String p_file_path, String p_data) throws Exception 
{
  try {
    FileWriter outFile = new FileWriter(p_file_path,true);
    PrintWriter out = new PrintWriter(outFile);
    out.println(p_data);
  } catch (Exception  e) {
  } finally {
    out.close();
  }
  return SUCCESS;
}

Answer 1

如果你想

在 finally 块中引用它，你需要在 try-block 之外定义 "out"，类似于

PrintWriter out = null;
try
{
    FileWriter outFile = new FileWriter(p_file_path,true);
    out = new PrintWriter(outFile);
    out.println(p_data);
}
finally
{
    if (out != null)
        out.close();
}

Answer 2

您在try块中声明out。这意味着一旦您离开try-finally语句的try部分，这超出了范围。您可以在 try 语句之外声明它并在 finally 块中执行空检查，也可以使用 Java 7 的 try-with-resources 语句。

PrintWriter out;
try {
    out = ...
} finally {
    if(out != null) {
        out.close();
    }
}

或

try(PrintWriter out = ...) {
}