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;
}
};
www.zzzyk.com
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 ,