java代码向数据库安插数据报错

String s = "";        File f = new File(fileName);        if (!f.exists()) {            throw new Exception("file doesn't exist....");        }        BufferedReader br = null;        PreparedStatement pstmt = null;        try {            br = new BufferedReader(new InputStreamReader(                    new FileInputStream(f)));            String sql = "insert into tbl_report(a,b,c,d)"                    + "values(?,?,?,'2009-12-07')";            pstmt = con.prepareStatement(sql);            // 循环外部准备好prepareStatement;            while ((s = br.readLine()) != null) {                if (s.indexOf("合计") > 0) {                    continue;                }                String[] c = s.split("\t");                printArray(c);                if (c.length == 3) {                    // 加入批量参数                    pstmt.setString(1, c[0]);                    pstmt.setString(2, c[1]);                    pstmt.setString(3, c[2]);                    pstmt.addBatch();                }            }            // 一次执行。            pstmt.executeBatch();            System.out.println("file write back finished");        } catch (Exception e) {            throw e;        } finally {            try {                if (pstmt != null) {                    pstmt.close();                }                br.close();            } catch (Exception e) {                e.printStackTrace();            }        }