找不到地方插入finally塊來擺脫錯誤：插入最後完成TryStatement

Question

我已經嘗試了幾個插入finally塊的位置，但無論我嘗試什麼，都會導致代碼變得更糟。

這是我的代碼，第4個到最後的結束大括號是給我的錯誤。有什麼想法嗎？

    package com.tunestore.action;
 

    import java.io.InputStream; 
    import java.sql.Connection; 
    import java.sql.DriverManager; 
    import java.sql.ResultSet; 
    import java.sql.PreparedStatement; 

    import javax.servlet.http.HttpServletRequest; 
    import javax.servlet.http.HttpServletResponse; 

    import org.apache.commons.logging.Log; 
    import org.apache.commons.logging.LogFactory; 


    import org.apache.struts.action.Action; 
    import org.apache.struts.action.ActionForm; 
    import org.apache.struts.action.ActionForward; 
    import org.apache.struts.action.ActionMapping; 
    import org.apache.struts.action.ActionMessage; 
    import org.apache.struts.action.ActionMessages; 
    import org.apache.struts.action.DynaActionForm; 

    import java.io.*; 
    import javax.servlet.*; 
    import javax.servlet.http.*; 
    import org.owasp.validator.html.*; 
    import org.owasp.esapi.*; 

    public class DownloadAction extends Action 
    { 
     private static final Log log = LogFactory.getLog(DownloadAction.class); 

     public static String DB_URL; 

     static 
     { 
       if (System.getProperty("tunestore.db.location") != null) 
       { 
        DB_URL = "jdbc:derby://localhost:1527/" + System.getProperty("tunestore.db.location"); 
       } 
       else 
       { 
        DB_URL = "jdbc:derby://localhost:1527/" + System.getProperty("user.home") + "/.tunestore"; 
       } 
       System.setProperty("jdbc.tunestore.url", DB_URL); 
     } 

     public static Connection getConnection() throws Exception 
     { 
      log.info("Opening database at " + DB_URL); 
      Class.forName("org.apache.derby.jdbc.ClientDriver").newInstance(); 
      Connection conn = DriverManager.getConnection(DB_URL); 
      return conn; 
     } 


     public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) 
     throws Exception 
     { 
      DynaActionForm daf = (DynaActionForm)form; 
      String user = (String)request.getSession(true).getAttribute("USERNAME"); 
      if(user != null) 
      { 
       Connection conn = null; 
       try 
       { 
        conn = DownloadAction.getConnection(); 
        String sql2 = "SELECT ID FROM CD WHERE CD.BITS = ?"; 
        PreparedStatement stmt2 = conn.prepareStatement(sql2); 
        stmt2.setString(1, request.getParameter("cd")); 
        ResultSet rs2 = stmt2.executeQuery(); 
        rs2.next(); 

        String sql = "SELECT COUNT(*) " 
        + "FROM TUNEUSER_CD " 
        + "WHERE TUNEUSER_CD.TUNEUSER = ? AND TUNEUSER_CD.CD = ?"; 
        PreparedStatement stmt = conn.prepareStatement(sql); 
        stmt.setString(1, user); 
        stmt.setInt(2, rs2.getInt(1)); 
        ResultSet rs = stmt.executeQuery(); 
        rs.next(); 
        int owned = rs.getInt(1); 

        if(owned == 1) 
        { 
         try 
         { 
          // Try to open the stream first - if there's a goof, it'll be here 
          InputStream is = this.getServlet().getServletContext().getResourceAsStream("/WEB-INF/bits/" + request.getParameter("cd")); 

          if (is != null) 
          { 
           response.setContentType("audio/mpeg"); 
           response.setHeader("Content-disposition", "attachment; filename=" + daf.getString("cd"));  
           byte[] buff = new byte[4096]; 
           int bread = 0; 
           while ((bread = is.read(buff)) >= 0) 
           { 
            response.getOutputStream().write(buff, 0, bread); 
           } 
          } 
          else 
          { 
           ActionMessages errors = getErrors(request); 
           errors.add(ActionMessages.GLOBAL_MESSAGE, new ActionMessage("download.error")); 
           saveErrors(request, errors); 
           return mapping.findForward("error");   
          } 
         } 

         catch (Exception e) 
         { 
          e.printStackTrace(); 
          ActionMessages errors = getErrors(request); 
          errors.add(ActionMessages.GLOBAL_MESSAGE, new ActionMessage("download.error")); 
          saveErrors(request, errors); 
          return mapping.findForward("error"); 
         } 

         return null; 

        } 
       } 
      } 
     } 
    } 

Answer 1

即支架是你的外try塊結束的位置。它沒有catch塊，也沒有finally塊，所以你會得到一個錯誤。只需在支架後立即添加一個或另一個，或者如果不需要，請移除try。

Answer 2

您只有一個catch塊，但有兩個trys。爲第一次嘗試抓住添加一個catch塊，你應該解決你的問題。

編輯：你爲什麼在第一個地方嵌套try-catch？我不認爲有必要這樣做。