Java programmu izveidošana Oracle datu bāzē

1. Java klases failu ielāde DB izmantojot loadjava programmu.

2. Java klases izveidošana ar create java … komandu.

Datu bāzes sistēma

Fails ar Java klases

definējumu

CMD vide

loadjava programma

Datu bāzes sistēma

SQL*PLUS programma

SQL> create java ...

Serverī glabājamas Java valodas procedūras (stored procedures) izveidošanas un izmantošanas piemērs

1. Java klases definējuma ierakstīšana Sveiki.java failā.

public class Sveiki {public static String Teksts () { return "Sveiki! Sāksim lietot Javu datu bāzē."; } }

2. Java klases ielādēšana datu bāzē. Var veikt *.java vai *.class faila ielādi.

Failu glabāšanas katalogi:H:\oracle\product\10.1.0\Db_1\BIN\loadjava.bat H:\Java\Sveiki.javaKomandu fails ar saviem parametriem tiek palaists no kataloga H:\Java.

loadjava.bat -u sakne/janis@localhost:1521:BAZE –v –r -t Sveiki.java

option -v enables verbose (izplūdis) mode;option -r compiles uploaded Java source files and resolves external references in the classes;option -t tells loadjava to connect to the database using the client-side JDBC Thin driver.

2

3. Klases ielādes pārbaude (no SQL*Plus programmas).

col OBJECT_NAME format a30;col OBJECT_TYPE format a15;

select OBJECT_NAME, OBJECT_TYPE, STATUSfrom USER_OBJECTS;

OBJECT_NAME OBJECT_TYPE STATUS---------------------------------------------------------------------------------JAVA$OPTIONS TABLE VALIDSveiki JAVA CLASS VALIDSveiki JAVA SOURCE VALID

4. Java metodi izsaucošās PL/SQL funkcijas izveidošana .

create or replace function SVEIKI_TEKSTS return varchar2 as language java name 'Sveiki.Teksts () return java.lang.String';

5. Metadatu apskate.

select OBJECT_NAME, OBJECT_TYPE, STATUSfrom USER_OBJECTS;

OBJECT_NAME OBJECT_TYPE STATUS-------------------------------------------------------------------------JAVA$OPTIONS TABLE VALIDSveiki JAVA CLASS VALIDSveiki JAVA SOURCE VALIDSVEIKI_TEKSTS FUNCTION VALID

6. Datu bāzes un Java buferu inicializācija.

SQL>set serveroutput ON;SQL>call DBMS_JAVA.SET_OUTPUT(2000);

3

7. Izsaucošās PL\SQL funkcijas aktivēšana ar call izsaukumu.

SQL>variable mainigais_1 varchar2(40);SQL> call SVEIKI_TEKSTS() into :mainigais_1;SQL>print mainigais_1;

mainigais_1---------------------------------------Sveiki! Sāksim lietot Javu datu bāzē.

8. Izsaucošās PL\SQL funkcijas aktivēšana izmantojot SELECT vaicājumu.

select SVEIKI_TEKSTS from DUAL;

SVEIKI_TEKSTS-----------------------------------------------Sveiki! Saksim lietot Javu datu bāzē.

9. Ielādētās klases nodzēšana ar komandu dropjava.

OS vidē (RUN cmd ...) jāpalaiž komanda:dropjava -thin -u sakne/janis@localhost:1521:BAZE Sveiki.java

10. Metadatu apskate.

select OBJECT_NAME, OBJECT_TYPE, STATUSfrom USER_OBJECTS;

OBJECT_NAME OBJECT_TYPE STATUS-------------------------------------------------------------------------SVEIKI_TEKSTS FUNCTION VALID

!4

11. Klases ielāde izmantojot CREATE JAVA SOURCE NAMED ... komandu.

create or replace JAVA source named "Sveiki" aspublic class Sveiki {public static String Teksts (){ return "Sveiki! Sāksim lietot Java datu bāzē."; } };

12. Metadatu apskate. select OBJECT_NAME, OBJECT_TYPE, STATUSfrom USER_OBJECTS;OBJECT_NAME OBJECT_TYPE STATUS------------------------------------------------------------------------------------Sveiki JAVA CLASS INVALIDSveiki JAVA SOURCE INVALIDSVEIKI_TEKSTS FUNCTION VALID

13. Izsaucošās PL/SQL funkcijas pārdefinēšana.

create or replace function SVEIKI_TEKSTS return varchar2 as language java name 'Sveiki.Teksts () return java.lang.String';

14. Izsaucošās PL\SQL funkcijas aktivēšana izmantojot SELECT vaicājumu.

select SVEIKI_TEKSTS from DUAL;

SVEIKI_TEKSTS-----------------------------------------------Sveiki! Saksim lietot Javu datu bāzē.

5

15. Java objektu nodzēšana no DBVS vides ar komandu drop java

drop java source "Sveiki";drop java class "Sveiki";

Izmantotās simbolu koda tabulas noteikšana

variable m1 varchar2(50);call DBMS_JAVA.GET_COMPILER_OPTION(NULL, 'encoding') into :m1;print m1;

m1------------------------WINDOWS-1252

6

Piemērs main metodes parametru transformācijai

As a rule, Java names and call spec parameters must correspond one to one. However, that rule does not apply to method main. Its String[] parameter can be mapped to multiple CHAR or VARCHAR2 call spec parameters.

Faila F:\Atbalss.java saturs:

public class Atbalss { public static void main (String[] args) { for (int i = 0; i < args.length; i++) System.out.println(args[i]); } }

loadjava -u java_liet/janis@DATORS:1521:BAZE –v –r -t F:\Atbalss.java

create or replace procedure ATBALSS ( s1 varchar2, s2 varchar2, s3 varchar2)as language JAVA name 'Atbalss.main(java.lang.String[])';

call ATBALSS('AAA', 'BBB', 'CCC');

Rezultāts:AAABBBCCC

You cannot impose constraints (such as precision, size, or NOT NULL) on call spec parameters. So, you cannot specify a maximum size for the VARCHAR2 parameters.

7

Datu ievade tabulā izmantojot Java klasi Firma un metodi FirmaInsert

1. Tabulas izveidošana

create table FIRMAS(F_NUM number Primary key,F_NOS varchar2(30),DIB_DAT varchar2(10)); 2. Klases Firma koda ierakstīšana failā O:\Firma.java

import java.sql.*;import java.io.*;import oracle.jdbc.*;public class Firma{public static void FirmaInsert (int f_num, String f_nos, String dib_dat) throws SQLException { String sql = "insert into FIRMAS values (?,?,?)"; try {Connection conn = DriverManager.getConnection("jdbc:default:connection:"); PreparedStatement pstmt = conn.prepareStatement(sql); pstmt.setInt(1, f_num); pstmt.setString(2, f_nos); pstmt.setString(3, dib_dat); pstmt.executeUpdate(); pstmt.close(); } catch (SQLException e) {System.err.println(e.getMessage());} } }

3. Klases Firma koda ielāde datu bāzē (tiek izmantots CMD)Ielādes komanda:

O:\oracle\product\10.1.0\Db_1\bin\loadjava -u system/janis@DATORS:1521:BAZE –v –r -t O:\Firma.java

static – elements, kurš pieder klasei, bet nepieder klases eksemplāriem.void – metodes, kura neatgriež nekādu vērtību, apzīmētājs.throws – ģenerē īpašās situācijas, kuras var izveidoties metodē.try – bloks, kurš piedalās īpašo situāciju pārtveršanā.catch – īpašās situācijas (ja tāda izveidojas blokā, kurš definēts ar throws) apstrāde.

8

4. Programmu paketes PAKETE_F ar PL/SQL procedūru FIRMA_INSERT, kura izsauc klases Firma metodi FirmaInsert, izveide create or replace package PAKETE_F as procedure FIRMA_INSERT (f_num number, f_nos varchar2, dib_dat varchar2);end PAKETE_F;

create or replace package body PAKETE_F as procedure FIRMA_INSERT(f_num number, f_nos varchar2, dib_dat varchar2) as language JAVA name 'Firma.FirmaInsert(int, java.lang.String, java.lang.String)';end PAKETE_F;

5. PL/sql procedūras FIRMA_INSERT izsaukšana

sql>call PAKETE_F.FIRMA_INSERT(1, 'AAA', '21-FEB-01');

6. Datu bāzes tabulas FIRMAS satura apskate

select * from FIRMAS; F_NUM F_NOS DIB_DAT--------------------------------------------------------------- 1 AAA 21-FEB-01

7. Metadatu apskate

9

select OBJECT_NAME, OBJECT_TYPE, STATUSfrom USER_OBJECTS;

OBJECT_NAME OBJECT_TYPE STATUS-------------------------------------------------------------------------Firma JAVA CLASS VALIDFirma JAVA SOURCE VALIDPAKETE_F PACKAGE VALIDPAKETE_F PACKAGE BODY VALID

10

Datu izguve no tabulas FIRMAS izmantojot Java klasi Firma, metodes FirmaSelect un Izvade

1. Iepriekšējā klases definējuma nodzēšana

O:\oracle\product\10.1.0\Db_1\bin\dropjava -thin -u system/janis@DATORS:1521:BAZE O:\Firma.java

2. Klases Firma definējuma ierakstīšana failā FIRMAS.java

import java.sql.*;import java.io.*;import oracle.jdbc.*;public class Firma{

public static void FirmaSelect (String f_nos) throws SQLException { String sql = "select A.F_NUM, A.F_NOS, A.DIB_DAT " + " from FIRMAS A" + " where A.F_NOS = ?"; try { Connection conn = DriverManager.getConnection("jdbc:default:connection:"); PreparedStatement pstmt = conn.prepareStatement(sql); pstmt.setString(1, f_nos); ResultSet rset = pstmt.executeQuery(); Izvade(rset); rset.close(); pstmt.close(); } catch (SQLException e) {System.err.println(e.getMessage());} } }

public static void FirmaInsert (int f_num, String f_nos, String dib_dat) ...

11

static void Izvade (ResultSet rset) throws SQLException { String buffer = ""; try { ResultSetMetaData meta = rset.getMetaData(); int cols = meta.getColumnCount(), rows = 0; for (int i = 1; i <= cols; i++) {int size = meta.getPrecision(i); String label = meta.getColumnLabel(i); if (label.length() > size) size = label.length(); while (label.length() < size) label += " "; buffer = buffer + label + " "; } buffer = buffer + "\n"; while (rset.next()) { rows++; for (int i = 1; i <= cols; i++) { int size = meta.getPrecision(i); String label = meta.getColumnLabel(i); String value = rset.getString(i); if (label.length() > size) size = label.length(); while (value.length() < size) value += " "; buffer = buffer + value + " "; } buffer = buffer + "\n"; } if (rows == 0) buffer = "No data found!\n"; System.out.println(buffer); } catch (SQLException e) {System.err.println(e.getMessage());} }

3. Klases Firma ielāde datu bāzē

O:\oracle\product\10.1.0\Db_1\bin\loadjava -u system/janis@DATORS:1521:BAZE –v –r -t O:\Firma.java

12

4. PL/SQL paketes un izsaucošās procedūras izveidošana

create or replace package PAKETE_F as procedure FIRMA_INSERT (f_num number, f_nos varchar2, dib_dat varchar2); procedure Firma_SELECT (f_nos varchar2);end PAKETE_F;

create or replace package body PAKETE_F as procedure FIRMA_INSERT(f_num number, f_nos varchar2, dib_dat varchar2) as language JAVA name 'Firma.FirmaInsert(int, java.lang.String, java.lang.String)';

procedure FIRMA_SELECT (f_nos varchar2) as language JAVA name 'Firma.FirmaSelect(java.lang.String)';end PAKETE_F;

5. Metadatu izvade

col OBJECT_NAME format a30;col OBJECT_TYPE format a15;select OBJECT_NAME, OBJECT_TYPE, STATUSfrom USER_OBJECTS;OBJECT_NAME OBJECT_TYPE STATUS------------------------------------------------------------------------------Firma JAVA CLASS VALIDFirma JAVA SOURCE VALIDPAKETE_F PACKAGE VALIDPAKETE_F PACKAGE BODY VALIDFIRMAS TABLE VALID

13

6. Eksistējošo datu nodzēšana un jauno ievade datu bāzes tabulā FIRMAS

delete FIRMAS;insert into FIRMAS values(1, 'CCC', '21-07-1990');

7. Izsaucošās PL/SQL procedūras FIRMA_SELECT aktivizēšana

SQL> SET SERVEROUTPUT ONSQL> CALL dbms_java.set_output(2000);

SQL> CALL PAKETE_F.FIRMA_SELECT('CCC');

F_NUM F_NOS DIB_DAT 1 CCC 21-07-1990

14

Skata USER_OBJECTS kolonas

Column Datatype NULL Description

OWNER VARCHAR2(30) NOT NULL

Owner of the object

OBJECT_NAME VARCHAR2(30) NOT NULL

Name of the object

SUBOBJECT_NAME VARCHAR2(30) Name of the subobject (for example, partition)

OBJECT_ID NUMBER NOT NULL

Dictionary object number of the object

DATA_OBJECT_ID NUMBER Dictionary object number of the segment that contains the object

Note: OBJECT_ID and DATA_OBJECT_ID display data dictionary metadata. Do not confuse these numbers with the unique 16-byte object identifier (object ID) that the Oracle Database assigns to row objects in object tables in the system.

OBJECT_TYPE VARCHAR2(19) Type of the object (such as TABLE, INDEX)

CREATED DATE NOT NULL

Timestamp for the creation of the object

LAST_DDL_TIME DATE NOT NULL

Timestamp for the last modification of the object resulting from a DDL statement (including grants and revokes)

TIMESTAMP VARCHAR2(20) Timestamp for the specification of the object (character data)

STATUS VARCHAR2(7) Status of the object (VALID, INVALID, or N/A)

TEMPORARY VARCHAR2(1) Whether the object is temporary (the current session can see only data that it placed in this object itself)

GENERATED VARCHAR2(1) Was the name of this object system generated? (Y|N)

SECONDARY VARCHAR2(1) Whether this is a secondary object created by the ODCIIndexCreate method of the Oracle Data Cartridge (Y | N)

15

Skata DBA_JAVA_CLASSES kolonas

Column Datatype NULL DescriptionOWNER VARCHAR2(30) NOT

NULLOwner of the Java class

NAME VARCHAR2(4000)   Name of the Java classMAJOR NUMBER   Major version number of the Java class, as defined in the

JVM specificationMINOR NUMBER   Minor version number of the Java class, as defined in the

JVM specificationKIND VARCHAR2(9)   Indicates whether the stored object is a Java class (CLASS)

or a Java interface (INTERFACE)ACCESSIBILITY VARCHAR2(6)   Accessibility of the Java classIS_INNER VARCHAR2(3)   Indicates whether this Java class is an inner class (YES) or

not (NO)IS_ABSTRACT VARCHAR2(3)   Indicates whether this Java class is an abstract class (YES)

or not (NO)IS_FINAL VARCHAR2(3)   Indicates whether this Java class is a final class (YES) or

not (NO)IS_DEBUG VARCHAR2(3)   Indicates whether this Java class contains debug

information (YES) or not (NO)SOURCE VARCHAR2(4000)   Source designation of the Java classSUPER VARCHAR2(4000)   Super class of this Java classOUTER VARCHAR2(4000)   Outer class of this Java class if this Java class is an inner

class

16