java - 将退出代码从 Java 返回到 PL/SQL

Question

我正在尝试将退出代码从 Java 方法返回到 PL/SQL。看来总有异常(exception)。我怎样才能找出什么异常是。我在 12c 上运行。

SQL> CREATE OR REPLACE JAVA SOURCE NAMED UTLCMD AS
  2  import java.lang.Runtime;
  3  public class UTLCMD
  4  {
  5      public static int execute(String command)
  6      {
  7          int exitCode = 0;
  8
  9          try
 10          {
 11              Runtime rt = java.lang.Runtime.getRuntime();
 12              Process proc = rt.exec(command);
 13              exitCode = proc.waitFor();
 14          }
 15          catch(Exception e)
 16          {
 17              System.out.println(e.getMessage());
 18              exitCode = 12;
 19          }
 20
 21          return exitCode;
 22      }
 23  }
 24  /

Java created.

SQL> CREATE OR REPLACE FUNCTION JavaRunShellCommand(
  2      command IN VARCHAR2)
  3      RETURN NUMBER
  4  AS LANGUAGE JAVA
  5      NAME 'UTLCMD.execute(java.lang.String) return oracle.sql.NUMBER';
  6  /

Function created.

以下是尝试调用该方法的结果。

SQL> VARIABLE n NUMBER;
SQL> CALL JavaRunShellCommand('cmd.exe /C CALL C:\Users\pwatson\src\java\my.bat') INTO :n;

Call completed.

SQL> PRINT n

         N
----------
        12

SQL> CALL JavaRunShellCommand('cmd.exe /C EXIT /B 3') INTO :n;

Call completed.

SQL> PRINT n

         N
----------
        12

SQL> SELECT JavaRunShellCommand('cmd.exe /C CALL C:\Users\pwatson\src\java\my.bat') AS R FROM DUAL;

         R
----------
        12

SQL> SELECT JavaRunShellCommand('cmd.exe /C EXIT /B 3') AS R FROM DUAL;

         R
----------
        12

Answer 1

由于返回了 12，因此您收到了异常，但是您捕获了所有异常，并且仅使用 System.out.println() 显示它们，并且 Java 控制台输出进入跟踪文件 - 您(或您的 DBA)需要找到正确的文件并提取实际的错误。

让异常抛出会更简单:

CREATE OR REPLACE JAVA SOURCE NAMED UTLCMD AS
import java.lang.Runtime;
public class UTLCMD
{
    public static int execute(String command)
    throws java.lang.InterruptedException, java.io.IOException
    {
        int exitCode = 0;
        Runtime rt = java.lang.Runtime.getRuntime();
        Process proc = rt.exec(command);
        exitCode = proc.waitFor();
        return exitCode;
    }
}
/

如果我使用命令(在我的例子中是 Unix-y)运行它，那么我就会看到真正的问题:

exec :n := JavaRunShellCommand('/bin/ls /tmp');

ORA-29532: Java call terminated by uncaught Java exception: java.security.AccessControlException: the Permission (java.io.FilePermission /bin/ls execute) has not been granted to STACKOVERFLOW. The PL/SQL to grant this is dbms_java.grant_permission( 'STACKOVERFLOW', 'SYS:java.io.FilePermission', '/bin/ls', 'execute' )
ORA-06512: at "STACKOVERFLOW.JAVARUNSHELLCOMMAND", line 1
ORA-06512: at line 1
29532. 00000 -  "Java call terminated by uncaught Java exception: %s"
*Cause:    A Java exception or error was signaled and could not be
           resolved by the Java code.
*Action:   Modify Java code, if this behavior is not intended.

这与我在尝试按照您的方式时在跟踪文件中看到的相同，但更容易访问。

如果我按照错误提示通过发出 dbms_java.grant_permission() 调用(作为 DBA)来解决我的问题，然后重新连接，它现在可以工作了:

exec :n := JavaRunShellCommand('/bin/ls /tmp');
anonymous block completed

print n
N
-
0

当然，您很可能会遇到不同的异常，但您需要先找出它是什么，然后才能开始解决真正的问题。