Question

我必须监视多个表以进行更改。我的数据库是Oracle11g，我使用的是ojdbc6.jar jdbc驱动程序库。问题是我得到了＆＃34; ???＆＃34;发生数据库更改事件时，而不是表名。 DatabaseChangeEvent中的所有其他数据都存在，只缺少表名。

我在网上找到了这个代码，我稍微根据自己的需要修改了这个代码。

这是程序输出：

Connection information  : local=ORATEST01/10.10.60.17:43000, remote=ORATEST01/10
.10.60.17:52683
Registration ID         : 63
Notification version    : 1
Event type              : OBJCHANGE
Database name           : fmvroratest
Table Change Description (length=1)
    operation=[UPDATE], tableName=???, objectNumber=73786
    Row Change Description (length=2):
      ROW:  operation=UPDATE, ROWID=AAASA6AAHAAACEEAAA
      ROW:  operation=UPDATE, ROWID=AAASA6AAHAAACEEAAA

Table changed: ???




package hr.mspoljaric.dcn;

import java.sql.*;
import java.util.*;
import oracle.jdbc.*;
import oracle.jdbc.dcn.*;

public class OracleDCN {
    String URL = "jdbc:oracle:thin:**********************************";
    Properties prop;

    public static void main(String[] argv) {

        OracleDCN dcn = new OracleDCN();
        try {
            dcn.prop = new Properties();
            dcn.run();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    void run() throws SQLException {
        OracleConnection conn = (OracleConnection) DriverManager.getConnection(
                URL, prop);

        Properties prop = new Properties();
        prop.setProperty(OracleConnection.DCN_NOTIFY_ROWIDS, "true");
        prop.setProperty(OracleConnection.NTF_LOCAL_TCP_PORT, "43000");

        DatabaseChangeRegistration dcr = conn
                .registerDatabaseChangeNotification(prop);

        try {
            dcnListener list = new dcnListener(this);
            dcr.addListener(list);

            Statement stmt = conn.createStatement();
            ((OracleStatement) stmt).setDatabaseChangeRegistration(dcr);
            ResultSet rs = stmt
                    .executeQuery("select 1 from klijent, osobe where 1=2");
            rs.close();
            stmt.close();

        } catch (Exception e) {
            // clean up our registration
            if (conn != null)
                conn.unregisterDatabaseChangeNotification(dcr);
            e.printStackTrace();
        } finally {
            try {
                conn.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        try {

            Thread.currentThread().join();

        } catch (Exception e) {
            e.printStackTrace();
        }

        finally {
            OracleConnection conn3 = (OracleConnection) DriverManager
                    .getConnection(URL, prop);
            conn3.unregisterDatabaseChangeNotification(dcr);
            conn3.close();
        }
    }
}

class dcnListener implements DatabaseChangeListener {
    OracleDCN dcn;

    dcnListener(OracleDCN dem) {
        dcn = dem;
    }

    public void onDatabaseChangeNotification(DatabaseChangeEvent e) {

        System.out.println(e.toString());

        TableChangeDescription[] tcds = e.getTableChangeDescription();

        for (TableChangeDescription tcd: tcds) 
            System.out.println("Table changed: " + tcd.getTableName());

        synchronized (dcn) {
            dcn.notify();
        }
    }
}

Answer 1

通过以下解决方法解决。由于我在响应中得到了objectNumber，我在这个额外的select中使用这个数字来获取表名：

select object_name from user_objects where object_id=73786

Answer 2

???表示字符集转换错误。＆＃34;＆＃34;是转换期间发生错误时的标准替换字符。如果您的表名具有非ascii字符，那么可能会解释您在通知中看不到其名称的原因。

无法通过Oracle数据库更改通知获取表名称

2 个答案: