Horst Keller has already introduced ADBC in his blog ABAP Geek 15 – ADBC long times ago. And recently during my self study on PostgreSQL I made some practice to connect PostgreSQL in Java programming using Java Database Connectivity – JDBC. In fact I found out that there are lots of commonality between these two technologies.

There is a demo program demo_adbc_query mentioned in SAP help to demonstrate the use of ADBC.

I make some changes on it in order to perform a line-by-line comparison with JDBC.
The source code of adapted program:

REPORT zjerry_adbc.CLASS demo DEFINITION.PUBLIC SECTION.CLASS-METHODS main.PRIVATE SECTION.CLASS-DATA: BEGIN OF result_line,carrid TYPE sflight-carrid,connid TYPE sflight-connid,fldate TYPE sflight-fldate,END OF result_line,result_tab LIKE TABLE OF result_line. ENDCLASS.CLASS demo IMPLEMENTATION.METHOD main.DATA: carrid TYPE sflight-carrid VALUE 'AA',cols TYPE adbc_column_tab,lv_carrid TYPE string,con_ref TYPE REF TO cl_sql_connection,con_name TYPE dbcon-con_name VALUE 'DEFAULT'.cols = VALUE #( ( CONV adbc_name( 'CARRID' ) )( CONV adbc_name( 'CONNID' ) )( CONV adbc_name( 'FLDATE' ) ) ).lv_carrid = cl_abap_dyn_prg=>quote( to_upper( carrid ) ).TRY.con_ref = cl_sql_connection=>get_connection( con_name ).DATA(statement) = con_ref->create_statement( ).DATA(lv_query) = `SELECT carrid, connid, fldate ` &&`FROM sflight ` &&`WHERE mandt = ` && `'` && sy-mandt && `' AND` &&` carrid = ` && lv_carrid.DATA(result) = statement->execute_query( lv_query ).result->set_param_table( itab_ref = REF #( result_tab )corresponding_fields = cols ).IF result->next_package( ) > 0.SORT result_tab BY carrid connid fldate.WRITE:/ 'Number of lines found: ', lines( result_tab ).ENDIF.con_ref->close( ).CATCH cx_sql_exception INTO DATA(err).ENDTRY.ENDMETHOD. ENDCLASS.START-OF-SELECTION.demo=>main( ).

And now have a look at how JDBC can achieve the same.

I have replicated an ABAP table COMM_PRODUCT to my local PostgreSQL server:

And I manually inserted two test records into it:

Both is the source code implemented in Java to perform a query against this table and display result：

import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.sql.Timestamp; public class PostgreSQLJDBC {private Connection connection = null;private void select() {try {int index = 0;Class.forName("org.postgresql.Driver");connection = DriverManager.getConnection("jdbc:postgresql://localhost:9812/zproduct", "postgres", "XXXXXX");Statement stmt = connection.createStatement();String query = "SELECT * FROM public.comm_product;";ResultSet rs = stmt.executeQuery(query);while ( rs.next() ) {System.out.println("Row index: " + index++);String client = rs.getString("client");System.out.println("Client: " + client);String guid = rs.getString("product_guid");System.out.println("Product guid: " + guid);Timestamp validFrom = rs.getTimestamp("valid_from");System.out.println("Valid from: " + validFrom);}rs.close();stmt.close();connection.close();} catch (Exception e) {e.printStackTrace();} }public static void main(String args[]) {PostgreSQLJDBC jdbcTest = new PostgreSQLJDBC();jdbcTest.select();} }

Output in console:

And I mark the corresponding part in both language which has the same semantic meaning with same color ( although grammar is different ).

Through this comparison we can know that both connectivity technology follow the same idea.

Further reading

I have written a series of blogs which compare the language feature among ABAP, JavaScript and Java. You can find a list of them below:

• Lazy Loading, Singleton and Bridge design pattern in JavaScript and in ABAP
• Functional programming – Simulate Curry in ABAP
• Functional Programming – Try Reduce in JavaScript and in ABAP
• Simulate Mockito in ABAP
• A simulation of Java Spring dependency injection annotation @Inject in ABAP
• Singleton bypass – ABAP and Java
• Weak reference in ABAP and Java
• Fibonacci Sequence in ES5, ES6 and ABAP
• Java byte code and ABAP Load
• How to write a correct program rejected by compiler: Exception handling in Java and in ABAP
• An small example to learn Garbage collection in Java and in ABAP
• String Template in ABAP, ES6, Angular and React
• Try to access static private attribute via ABAP RTTI and Java Reflection
• Local class in ABAP, Java and JavaScript
• Integer in ABAP, Java and JavaScript
• Covariance in Java and simulation in ABAP
• Various Proxy Design Pattern implementation variants in Java and ABAP
• Tag(Marker) Interface in ABAP and Java
• Bitwise operation ( OR, AND, XOR ) on ABAP Integer
• ABAP ICF handler and Java Servlet
• ADBC and JDBC
• CL_ABAP_CORRESPONDING, CL_JAVA_CORRESPONDING and CL_JS_CORRESPONDING
• Build an Cross Site Scripting example in Java and ABAP
• Play around with JSONP in nodeJS server and ABAP server

要獲取更多Jerry的原創文章，請關注公眾號"汪子熙":

總結

以上是生活随笔為你收集整理的SAP ABAP ADBC和Java JDBC的使用比较的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。