oracle调用java

其它语言的函数的调用
java函数调用

在oracle数据库建立一个java资源，也可以用loadjava命令装载其它的java类或者jar

create or replace and compile java sourcenamed mytestjava as
public class Factorial {
public static int calcFactorial (int n) {
if (n == 1) return 1;
else return n * calcFactorial (n - 1) ;
}
}

建立一个映射函数
CREATE OR REPLACE FUNCTION plstojavafac_fun
(N NUMBER)
RETURN NUMBER
AS
LANGUAGE JAVA
NAME 'Factorial.calcFactorial (int) return int';

selectplstojavafac_fun(4) from dual
----
24

这是一个极其简单的例子，但是有了这样的功能，你可以调用外部的任何外部命令，也可以与其他任何外部数据库数据文件进行通讯了

下面一个例子，实现在数据库内调用任何外部命令的功能

CREATE OR REPLACE AND COMPILE JAVA SOURCE NAMED "Host" AS
import java.io.*;
public class Host {
public static void executeCommand(String command) {
    try {
      String[] finalCommand;
      if (isWindows()) {
        finalCommand = new String[4];
        // Use the appropriate path for your windows version.
        finalCommand[0] = "C:\\windows\\system32\\cmd.exe"; // Windows XP/2003
        //finalCommand[0] = "C:\\winnt\\system32\\cmd.exe"; // Windows NT/2000
        finalCommand[1] = "/y";
        finalCommand[2] = "/c";
        finalCommand[3] = command;
      }
      else {
        finalCommand = new String[3];
        finalCommand[0] = "/bin/sh";
        finalCommand[1] = "-c";
        finalCommand[2] = command;
      }

      final Process pr = Runtime.getRuntime().exec(finalCommand);
      pr.waitFor();
      new Thread(new Runnable(){
        public void run() {
          BufferedReader br_in = null;
          try {
            br_in = new BufferedReader(new InputStreamReader(pr.getInputStream()));
            String buff = null;
            while ((buff = br_in.readLine()) != null) {
              System.out.println("Process out :" + buff);
              try {Thread.sleep(100); } catch(Exception e) {}
            }
            br_in.close();
          }
          catch (IOException ioe) {
            System.out.println("Exception caught printing process output.");
            ioe.printStackTrace();
          }
          finally {
            try {
              br_in.close();
            } catch (Exception ex) {}
          }
        }
      }).start();

      new Thread(new Runnable(){
        public void run() {
          BufferedReader br_err = null;
          try {
            br_err = new BufferedReader(new InputStreamReader(pr.getErrorStream()));
            String buff = null;
            while ((buff = br_err.readLine()) != null) {
              System.out.println("Process err :" + buff);
              try {Thread.sleep(100); } catch(Exception e) {}
            }
            br_err.close();
          }
          catch (IOException ioe) {
            System.out.println("Exception caught printing process error.");
            ioe.printStackTrace();
          }
          finally {
            try {
              br_err.close();
            } catch (Exception ex) {}
          }
        }
      }).start();
    }
    catch (Exception ex) {
      System.out.println(ex.getLocalizedMessage());
    }
}

public static boolean isWindows() {
    if (System.getProperty("os.name").toLowerCase().indexOf("windows") != -1)
      return true;
    else
      return false;
}
};

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在调用外部程序之前，必须授权给数据库用户相应的权限

-- Created on 2007-9-13 by Tiwen
declare
begin
DBMS_JAVA.grant_permission('TIWEN','java.io.FilePermission', '&

补充：软件开发 , Java ,