JSP 檔案操作：追加寫入篇

透過 JavaBean 實現文字檔案追加寫入。需預先放置 afile.txt 於 Web 根目錄 test 資料夾。

writeAppend.jsp

<jsp:useBean id="writer" class="WriteAppend" scope="request">
  <jsp:setProperty name="writer" property="path" value="/path/to/afile.txt" />
  <jsp:setProperty name="writer" property="something" value="初始化" />
</jsp:useBean>
<% writer.setSomething("追加資料"); %>
<% out.print(writer.getSomething()); %>
<% out.print(writer.writeSomething()); %>

WriteAppend.java

public class WriteAppend {
  private String path, something;
  public String writeSomething() {
    try {
      FileWriter fw = new FileWriter(path, true); // true = append
      PrintWriter out = new PrintWriter(fw);
      out.print(something + "\r\n");
      out.close(); fw.close();
      return "success!!";
    } catch (IOException e) { return e.toString(); }
  }
  // getter/setter 省略
}

關鍵：new FileWriter(path, true) 開啟追加模式。配合前篇「寫入篇」（覆蓋模式）掌握檔案基本操作。