java连接模式导致ORA-12516 - 《Oracle》

方式一：
java.sql.Connection conn = DriverManager.getConnection(“jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=orcl)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=orcl)))”,”scott”,”tiger”);

方式二：
java.sql.Connection conn = DriverManager.getConnection(“jdbc:oracle:thin:@orcl:1521/orcl”,”scott”,”tiger”);

前面orcl为数据库域名

使用下面脚本将客户端连接执行过程打印

cat Demo.java 
import java.sql.DriverManager;
import java.util.logging.*;
import javax.management.*;
import java.lang.management.*;
public class Demo{
        public static void main(String[] args) throws Exception{
                Class.forName("oracle.jdbc.driver.OracleDriver");
                enableOracleLogging();
                // 方法一
                java.sql.Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=scan)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=xiamen)))","scott","tiger");
                // 方法二
                //java.sql.Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@orcl:1521/orcl","scott","tiger");
                java.sql.Statement stmt = conn.createStatement();
                java.sql.ResultSet rs = stmt.executeQuery("select instance_name from v$instance");
                while(rs.next()){
                        System.out.println(rs.getString(1));
        }
}
private static void enableOracleLogging(){
        try {
                Handler fh = new FileHandler("./oracle_jdbc_log.log");
                fh.setLevel(Level.ALL);
                fh.setFormatter(new SimpleFormatter());
                Logger.getLogger("").addHandler(fh);
                Logger.getLogger("").setLevel(Level.ALL);
                MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
                String loader = Thread.currentThread().getContextClassLoader().toString().replaceAll("[,=:\"]+", "");
                ObjectName pattern = new ObjectName("com.oracle.jdbc:type=diagnosability,name=" + loader);
                ObjectName diag = ((ObjectName[]) (mbs.queryNames(pattern, null).toArray(new ObjectName[0])))[0];
                mbs.setAttribute(diag, new Attribute("LoggingEnabled", true));
        }catch(Exception e) {
                e.printStackTrace();
                }
            }
}

编译:
javac Demo.java
如果报错，换一个办法编译
[root@orcl ~]# javac -version
javac 1.8.0_301
使用ojdbc6进行连接
java -classpath /u01/app/oracle/product/11.2.0/db_1/jdbc/lib/ojdbc6_g.jar:./ Demo

方法一的日志：（直接将完整字符串发送到数据库，让数据库的dns进行解析）
如果数据库服务器上没有配置DNS解析，就会报ORA-12516的错误

Aug 18, 2021 2:21:45 PM oracle.net.ns.Packet send
TRACE_20: 3F0EE7CB Debug:
 00 E3 00 00 01 00 00 00     |........|
 01 36 01 2C 0C 41 20 00     |.6.,.A..|
 7F FF 4F 98 00 00 00 01     |..O.....|
 00 A9 00 3A 00 00 00 00     |...:....|
 81 81 00 00 00 00 00 00     |........|
 00 00 00 00 00 00 00 00     |........|
 00 00 00 00 00 00 00 00     |........|
 00 00 28 44 45 53 43 52     |..(DESCR|
 49 50 54 49 4F 4E 3D 28     |IPTION=(|
 41 44 44 52 45 53 53 5F     |ADDRESS_|
 4C 49 53 54 3D 28 41 44     |LIST=(AD|
 44 52 45 53 53 3D 28 50     |DRESS=(P|
 52 4F 54 4F 43 4F 4C 3D     |ROTOCOL=|
 54 43 50 29 28 48 4F 53     |TCP)(HOS|
 54 3D 6F 72 63 6C 29 28     |T=orcl)(|
 50 4F 52 54 3D 31 35 32     |PORT=152|
 31 29 29 29 28 43 4F 4E     |1)))(CON|
 4E 45 43 54 5F 44 41 54     |NECT_DAT|
 41 3D 28 43 49 44 3D 28     |A=(CID=(|
 50 52 4F 47 52 41 4D 3D     |PROGRAM=|
 4A 44 42 43 20 54 68 69     |JDBC.Thi|
 6E 20 43 6C 69 65 6E 74     |n.Client|
 29 28 48 4F 53 54 3D 5F     |)(HOST=_|
 5F 6A 64 62 63 5F 5F 29     |_jdbc__)|
 28 55 53 45 52 3D 6F 72     |(USER=or|
 61 63 6C 65 29 29 28 53     |acle))(S|
 45 52 56 49 43 45 5F 4E     |ERVICE_N|
 41 4D 45 3D 6F 72 63 6C     |AME=orcl|
 29 29 29                    |)))     |
Aug 18, 2021 2:21:45 PM oracle.net.ns.Packet send

方法二的日志：（在应用端解析完后，再将IP发送给数据库）

Aug 18, 2021 2:28:05 PM oracle.net.ns.Packet send
TRACE_20: 7DC36524 Debug:
 01 1B 00 00 01 00 00 00     |........|
 01 36 01 2C 0C 41 20 00     |.6.,.A..|
 7F FF 4F 98 00 00 00 01     |..O.....|
 00 E1 00 3A 00 00 00 00     |...:....|
 81 81 00 00 00 00 00 00     |........|
 00 00 00 00 00 00 00 00     |........|
 00 00 00 00 00 00 00 00     |........|
 00 00 28 44 45 53 43 52     |..(DESCR|
 49 50 54 49 4F 4E 3D 28     |IPTION=(|
 41 44 44 52 45 53 53 3D     |ADDRESS=|
 28 50 52 4F 54 4F 43 4F     |(PROTOCO|
 4C 3D 54 43 50 29 28 48     |L=TCP)(H|
 4F 53 54 3D 31 39 32 2E     |OST=192.|
 31 36 38 2E 32 34 37 2E     |168.247.|
 31 37 31 29 28 50 4F 52     |171)(POR|
 54 3D 31 35 32 31 29 29     |T=1521))|
 28 43 4F 4E 4E 45 43 54     |(CONNECT|
 5F 44 41 54 41 3D 28 43     |_DATA=(C|
 49 44 3D 28 50 52 4F 47     |ID=(PROG|
 52 41 4D 3D 4A 44 42 43     |RAM=JDBC|
 20 54 68 69 6E 20 43 6C     |.Thin.Cl|
 69 65 6E 74 29 28 48 4F     |ient)(HO|
 53 54 3D 5F 5F 6A 64 62     |ST=__jdb|
 63 5F 5F 29 28 55 53 45     |c__)(USE|
 52 3D 6F 72 61 63 6C 65     |R=oracle|
 29 29 28 53 45 52 56 49     |))(SERVI|
 43 45 5F 4E 41 4D 45 3D     |CE_NAME=|
 6F 72 63 6C 29 28 43 49     |orcl)(CI|
 44 3D 28 50 52 4F 47 52     |D=(PROGR|
 41 4D 3D 4A 44 42 43 20     |AM=JDBC.|
 54 68 69 6E 20 43 6C 69     |Thin.Cli|
 65 6E 74 29 28 48 4F 53     |ent)(HOS|
 54 3D 5F 5F 6A 64 62 63     |T=__jdbc|
 5F 5F 29 28 55 53 45 52     |__)(USER|
 3D 6F 72 61 63 6C 65 29     |=oracle)|
 29 29 29                    |)))     |
Aug 18, 2021 2:28:05 PM oracle.net.ns.Packet send