（轉載地址：http://blog.csdn.net/songyubin001/article/details/588815）
java與oracle的接口：
在數據庫中運行JAVA可以說是ORACLE8i的最令人激動的新特性。在你創建的使用ORACLE8i 數據庫的應用程序中，你可以使用與JAVA有關的新特徵，輕鬆的將程序發佈到INTERNET或INTRANET上。
Methods for Using Java in ORACLE==================================
大家都知道JAVA在跨平臺開發與INTERNET開發中已經比較流行，ORACLE8i及以後的版本中都包含了對在數據庫中運行JAVA的擴展支持，這裏有兩種方法可以使用：
JDBC：與ODBC類似, JDBC 提供了一個驅動接口使你可以在JAVA程序中訪問數據庫。注：JDBC驅動內嵌在數據庫中虛擬機中。
SQLJ：是一個JAVA預編譯器，它可以將內嵌的SQL語句轉化爲JAVA語句.SQLJ的使用與運行機理與其它ORACLE的與編譯器（如Pro*C，Pro*COBOL）類似。實際上，爲了使我們形象的記住SQLJ提供的功能，我們也可以直接將SQLJ改名爲Pro*Java。
將JAVA集成到數據庫中是雙向的。也就是說你可以在JAVA中調用SQL與PL/SQL,也可以在SQL與PL/SQL中調用JAVA。JAVA程序可以直接通過JDBC驅動調用SQL與PL/SQL，反過來，你也可以在SQL與PL/SQL中直接調用JAVA。在數據庫中，JAVA命名空間直接映射到數據庫模式的命名空間中，這樣可以方便JAVA的存取與調用。數據庫同時提供擴展的DDL語句，通過這些語句，你可以象創建一個存儲過程一樣在數據中創建內嵌的JAVA程序。
Features of ORACLE JDBC Drivers
=================================
在ORACLE8i中有三種類型的JDBC驅動，他們都使用相同的 syntax, APIs, and Oracle extensions，以使JAVA代碼在robust clients、Web-based Java applets, and Java stored procedures之間保持輕便靈活：三種類型如下：
1．JDBC OCI： 此驅動類似於傳統的ODBC 驅動。因爲它需要Oracle Call Interface and Net8，所以它需要在運行使用此驅動的JAVA程序的機器上安裝客戶端軟件
2．JDBC Thin： 這種驅動一般用在運行在WEB瀏覽器中的JAVA程序。它不是通過OCI or Net8，而是通過Java sockets進行通信 ，因此不需要在使用JDBC Thin的客戶端機器上安裝客戶端軟件。
3．JDBC KPRB： 這種驅動由直接存儲在數據庫中的JAVA程序使用，如Java Stored Procedures 、triggers、Database JSP's。It uses the default/ current database session and thus requires no additional database username, password or URL.
如何配置使JAVA可以通過Oracle JDBC Drivers連接到數據庫：1.安裝Sun JDK.
2. 修改PATH環境變量，使其指向JDK的bin目錄
3. 設置CLASSPATH環境變量，使其指向正確的JDK的lib及oracle的JDBC接口。
CLASSPATH = ".;????"
3. 運行"java ?version" ，驗證java的版本。
如何在不同的操作系統上根據接口類型設置客戶端：
對JDBC THIN接口：
在windows與unix下的設置方法一樣：
1．根據jdk的版本，只需要將classesxx.zip拷貝到指定的目錄，不需要安裝Oracle Client。在裝完數據庫後，該文件會在$ORACLE_HOME/jdbc/lib目錄下。2．設置CLASSPATH，使其包含上面的classesxx.zip
3．根據需要，拷貝oracle的其它zip文件並設置CLASSPATH
對JDBC OCI接口：
Fow Windows：
1．安裝Oracle Client.
2．根據jdk的版本，設置CLASSPATH，使其包含正確的classesxx.zip
3．根據需要設置CLASSPATH，使其指向Oracle的其它zip文件
4．設置PATH，使其包含$ORACLE_HOME/bin目錄
For unix：
1．安裝Oracle Client.
2．根據jdk的版本，設置CLASSPATH，使其包含正確的classesxx.zip
3．根據需要設置CLASSPATH，使其指向Oracle的其它zip文件
4．設置LD_LIBRARY_PATH，使其包含$ORACLE_HOME/lib目錄
備註：
classesxx.zip一般在ORACLE_HOME/jdbc/lib目錄下。
在ORACLE_HOME/jdbc/lib目錄下的與Oracle JDBC Drives驅動有關的文件的解釋：
- classes12.zip
Classes for use with JDK 1.2.x. It contains the JDBC driver
classes except classes necessary for NLS support in Object and
Collection types.
- nls_charset12.zip
NLS classes for use with JDK 1.2.x. It contains classes necessary
for NLS support in Object and Collection types.
- classes12_g.zip
Same as classes12.zip, except that classes were compiled with
"javac -g".
JDBC連接數據庫的語法：
JDBC THIN:
Code: [Copy to clipboard]
Connection conn=
DriverManager.getConnection
("jdbc:oracle:thin:@dlsun511:1521:ora1","scott","tiger");
| | |
machine(ip@) : port# : sid
JDBC OCI:
Code: [Copy to clipboard]
Connection conn=
DriverManager.getConnection
("jdbc:oracle:oci8[9]:@RAC","scott","tiger");
|
Net Service
JDBC THIN與JDBC THIN對比：
相同之處：
The JDBC Thin, JDBC OCI, and JDBC Server drivers all provide the same functionality. They all support the following standards and features:
* JDBC 2.0
* Partial JDBC 3.0 (in JDBC driver version 9.2)
* the same syntax and APIs
* the same Oracle extensions
至於不同之處是一個表格，不好上傳，大家自己總結吧！！
主要是JDBC OCI 接口比JDBC THIN接口效率高！
How does one connect with the JDBC Thin Driver?
The the JDBC thin driver provides the only way to access Oracle from the Web (applets). It is smaller and slower than the OCI drivers.
import java.sql.*;
Code: [Copy to clipboard]
class dbAccess {
public static void main (String args []) throws SQLException
{
DriverManager.registerDriver (
new oracle.jdbc.driver.OracleDriver()
);
Connection conn = DriverManager.getConnection
("jdbc:oracle:thin:@dbhost:1521:ORA1", "scott", "tiger");
// @machine:port:SID, userid, password
Statement stmt = conn.createStatement();
ResultSet rset = stmt.executeQuery (
"select BANNER from SYS.V_$VERSION"
);
while (rset.next())
System.out.println (rset.getString(1)); // Print col 1
stmt.close();
}
}
How does one connect with the JDBC OCI Driver?
One must have Net8 (SQL*Net) installed and working before attempting to use one of the OCI drivers.
Code: [Copy to clipboard]
import java.sql.*;
class dbAccess {
public static void main (String args []) throws SQLException
{
try {
Class.forName ("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
Connection conn = DriverManager.getConnection
("jdbc:oracle:oci8:@ORA1", "scott", "tiger");
// or oci9 @Service, userid, password
Statement stmt = conn.createStatement();
ResultSet rset = stmt.executeQuery (
"select BANNER from SYS.V_$VERSION"
);
while (rset.next())
System.out.println (rset.getString(1)); // Print col 1
stmt.close();
}
}
How does one connect with the JDBC KPRB Driver?
One can obtain a handle to the default or current connection (KPRB driver) by calling the OracleDriver.defaultConenction() method. Please note that you do not need to specify a database URL, username or password as you are already connected to a database session. Remember not to close the default connection. Closing the default connection might throw an exception in future releases of Oracle.
import java.sql.*;
Code: [Copy to clipboard]
class dbAccess {
public static void main (String args []) throws SQLException
{
Connection conn = (new
oracle.jdbc.driver.OracleDriver()).defaultConnection();
Statement stmt = conn.createStatement();
ResultSet rset = stmt.executeQuery (
"select BANNER from SYS.V_$VERSION"
);
while (rset.next())
System.out.println (rset.getString(1)); // Print col 1
stmt.close();
}
}
與JAVA有關的初始化參數：======================================
Executing initjvm.sql also highlights some new initsid.ora parameters that are used to support Java in your Oracle8i database. These parameters, their descriptions, and the settings required for running initjvm.sql, are all shown in the following list:
? SHARED_POOL_SIZE? Defines the size of your shared pool in bytes. This should be set to at least 50MB to run initjvm.sql.
? JAVA_POOL_SIZE? Defines the size of the Java pool, a new area of the SGA in Oracle8i used to store shared Java objects. This should be set to 50MB when running initjvm.sql, but can be as low as 20MB for normal use
of Java stored procedures.
? JAVA_SOFT_SESSIONSPACE_LIMIT? Identifies a soft limit on memory used by Java in a session. The default is 1MB. If this limit is exceeded, a warning is written to the ALERT log.
? JAVA_MAX_SESSIONSPACE_SIZE? Identifies the maximum amount of memory that can be used by a Java procedure; the default is 4GB. When the limit set by this parameter is exceeded, the executing Java procedure is killed by Oracle8i automatically.
如果將JAVA程序存放在數據庫中，並運行存儲在數據庫中的JAVA程序，則數據庫中會啓用JAVA的虛擬機，爲了保證JAVA虛擬機有效的運行，你需要設置上面介紹的參數。
如何將一個JAVA程序裝載到數據庫並且發佈出去？===================================
就像前面說得，java程序或類可以被存儲到數據庫中，作爲PL/SQL的替換或補充。Java可以被用來作爲數據庫的觸發器、存儲過程、函數、對象的成員函數。在按照下面的過程開發完java存儲過程後，就可以從SQL或PL/SQL中調用JAVA存儲過程，就像調用普通的PL/SQL過程一樣。下面的代碼描述瞭如何在SQL*PLUS中開發和使用一個 輸出"Hello, World" 的JAVA程序的例子：
1. Write the Java program using a Java development environment like Jdeveloper or JBuilder.
2. Load the Java program into Oracle8i using either the create or replace
java source command, or with the LOADJAVA utility.
3. Publish your Java procedure to SQL. This step identifies your Java
procedure to SQL and PL/SQL by exposing the procedure entry point,
mapping datatypes in Java to PL/SQL or SQL, and indicating
parameter-passing between Java and PL/SQL or SQL.
（1）編寫java程序
---可以直接在SQL*PLUS中創建JAVA的源文件，當然如果有已經編譯好的java class,則可以直接跳過這一步，直接到將java程序發佈出去這一步
SQL> -- first, create the Java source code
SQL> create or replace java source named "Hello" as
public class Hello {
static public String Message(String name) {
return "Hello, " + name;
}
}
/
Java created.
（2）發佈java程序
SQL> -- Now, publish it to SQL
SQL> create or replace function hello (name VARCHAR2) return VARCHAR2
as language java name
'Hello.Message (java.lang.String) return java.lang.String';
Function created.
（3）使用發佈的JAVA程序
SQL> -- Now, you can use the Java procedure from a SQL statement
SQL> select hello('world!') from dual;
HELLO('world!')
---------------
Hello world!
--- hello函數在8i中不支持中文，9i中支持。如：
SQL> select hello('你好!') from dual;
HELLO('你好!')
------------------
Hello, 你好!