小编Mik*_*ike的帖子

我创建了一个从我有权访问的FTP服务器下载文件的功能.如何将文件上传回FTP服务器？

下面是我使用的download_files方法:

public static void download_files(String un, String pw, String ip, String dir, String fn, String fp){

    URLConnection con;
    BufferedInputStream in = null;
    FileOutputStream out = null;

    try{
        URL url = new URL("ftp://"+un+":"+pw+"@"+ip+"/"+dir+"/"+fn+";type=i");
        con = url.openConnection();
        in = new BufferedInputStream(con.getInputStream());
        out = new FileOutputStream(fp+fn);

        int i = 0;
        byte[] bytesIn = new byte[1024];

        while ((i = in.read(bytesIn)) >= 0) {
            out.write(bytesIn, 0, i);
        }

    }catch(Exception e){
        System.out.print(e);
        e.printStackTrace();
        System.out.println("Error while FTP'ing "+fn);
    }finally{
        try{
            out.close();
            in.close();
        }catch(IOException e){
            e.printStackTrace();
            System.out.println("Error …

我试图通过以下方式获得结果集的行数:

rs.last();
int row_count = rs.getRow();

但我得到一个Invalid operation for forward only resultset : last错误.结果集从Oracle 10g数据库获取其数据.

这是我如何设置我的连接:

    Class.forName("oracle.jdbc.driver.OracleDriver");
    String connectionString = "jdbc:oracle:thin:@" + oracle_ip_address + ":" + oracle_db_port + ":" + oracle_db_sid;
    Connection conn = DriverManager.getConnection(connectionString, oracle_db_username, oracle_db_password);

我正在使用代码将字符串格式化为日期

String start_dt = '2011-01-01';

DateFormat formatter = new SimpleDateFormat("YYYY-MM-DD"); 
Date date = (Date)formatter.parse(start_dt);

但是如何将日期从YYYY-MM-DD格式转换为MM-DD-YYYY格式？

我之前从未在Oracle中创建过触发器,因此我正在寻找一些方向.

我想创建一个触发器,如果​​ID不在insert语句中,则将ID递增1.

ID应该从10000开始,并且当插入记录时,下一个ID应该是10001.如果insert语句包含ID,它应该覆盖自动增量.

即

insert into t1 (firstname, lastname) values ('Michael','Jordan'),('Larry','Bird')

应该是这样的:

firstname姓氏ID

Micahel Jordan 10000

拉里伯德10001

insert into t1 (firstname, lastname, id) values ('Scottie','Pippen',50000)

应该是这样的:

firstname姓氏ID

Micahel Jordan 10000

拉里伯德10001

Scottie Pippen 50000

我有一个json文件employees.json,我想将数据附加到此对象.该文件如下所示:

var txt = '{"employees":[' +
'{"firstName":"Jerry","lastName":"Negrell","time":"9:15 am","email":"jerry@bah.com","phone":"800-597-9405","image":"images/jerry.jpg" },' +
'{"firstName":"Ed","lastName":"Snide","time":"9:00 am","email":"edward@bah.com","phone":"800-597-9406","image":"images/ed.jpg" },' +
'{"firstName":"Pattabhi","lastName":"Nunn","time":"10:15 am","email":"pattabhi@bah.com","phone":"800-597-9407","image":"images/pattabhi.jpg" }'+
']}';

我想补充一下:

• 姓:麦克
• 名字:车辙
• 时间:上午10点
• 电子邮件:rut@bah.com
• 电话:800-888-8888
• 图像:图像/ mike.jpg

到employee.json.

我怎么做到这一点？

我有一个java程序,用于更新MS SQL中的表.Web用户也可以通过在ColdFusion中创建的网站访问此表

最近我遇到这个错误的时候:

sql_stmt.executeUpdate("update random_selection "
    + "set forecasted = 1 where "
    + " randnum = " + ora_rs.getString("RANDNUM")
    + " and quarter = " + quarter
    + " and ozip3 = " + ora_rs.getString("OZIP3"));

错误的CF查询是:

<cfquery name="submit_forecast" datasource="ttmsdropper" username="#request.db_username#" password="#request.db_password#">
    INSERT INTO forecast_entry
    VALUES (<cfqueryparam value="#currentRecord[8]#">)
</cfquery>

导致此错误的原因是什么？如何解决？

我使用SELECT语句从表中获取数据,然后将其插入另一个表.但是行"stmt.executeQuery(query);" 从表中插入第一行然后退出.当我注释掉这一行时,while循环遍历打印出来的所有行.堆栈跟踪未显示任何错误.为什么会这样？

try{                
    String query = "SELECT * FROM "+schema_name+"."+table;

    rs = stmt.executeQuery(query);

    while (rs.next()) {

        String bundle = rs.getString("BUNDLE");
        String project_cd = rs.getString("PROJECT_CD");
        String dropper = rs.getString("DROPPER");
        String week = rs.getString("WEEK");
        String drop_dt = rs.getString("DROP_DT").replace(" 00:00:00.0","");

        query = "INSERT INTO INDUCTION_INFO (BUNDLE, PROJECT_CD, DROPPER, WEEK, DROP_DT) "
              + "VALUES ("
              + bundle+","
              + "'"+project_cd+"',"
              + dropper+","
              + week+","
              + "to_date('"+drop_dt+"','YYYY-MM-DD'))";

        System.out.println(query);

        stmt.executeQuery(query);
    }
}catch(Exception e){
    e.printStackTrace();
}

我有一个本地MS SQL Server,我试图在java中使用JTDS连接到它.这是连接字符串:

Class.forName("net.sourceforge.jtds.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:jtds:sqlserver://localhost:1433/stock","sa","password");

和服务器属性:
名称:USER-PC\SQLEXPRESS
根目录:C:\ Program Files文件\ Microsoft SQL Server的\ MSSQL11.SQLEXPRESS\MSSQL

我收到了一个Exception in thread "main" java.sql.SQLException: Network error IOException: Connection refused: connect错误.

我该如何解决这个问题？

我正在运行代码,但是得到"无效状态,ResultSet对象已关闭".错误.是什么导致错误？

try{
    query = "SELECT * FROM BUNDLE_TEMP "
                  + "MINUS "
                  + "SELECT * FROM BUNDLE";

            rs = stmt.executeQuery(query);

            while (rs.next()){
                String bundle = rs.getString("BUNDLE");
                String week = rs.getString("WEEK");
                String sched_dt = rs.getString("SCHED_DT").replace(" 00:00:00.0", "");
                String dropper_id = rs.getString("DROPPER_ID");


                query = "INSERT INTO BUNDLE "
                            + "VALUES ('"
                                + bundle+"','"
                                + week+"','"
                                + sched_dt+"','"
                                + dropper_id+"')";

                stmt.executeUpdate(query);
            }
        }catch(Exception e){
            System.out.println("Error while trying to insert into BUNDLE\n"+query+"\n"+ e);
        }

我有一个存储在会话变量中的对象列表.但是当我检查以确保会话变量不为null时,它给了我一个NullReferenceException: Object reference not set to an instance of an object.

if(Session["object"] == null)  //error occurs here
{
     Session["object"] = GetObject();
     return Session["object"] as List<object>;
}
else
{
    return Session["object"] as List<object>;
}

如何检查Session是否为空？

编辑:我也试过了

if(Session["object"] != null)