Posts tagged json
The attraction of APEX has increased tremendously with the recent launch of the Oracle Cloud. APEX already supported departmental development and deployment of business applications with minimal involvement from the IT department (only a database needed be made available). Positioned as the ideal replacement for MS Access, APEX probably has managed better to capture the eye of developers and was used for enterprise application development at least as much as for the kind of tactical applications that Oracle strategically positioned it for.
With APEX as PaaS & DevaaS from the Oracle Cloud, a leap is made to a much higher level of business value. Now the IT department is not even needed to make infrastructure available with a database running on it. All the business needs is a credit card. And the business application that is developed, managed and used from the cloud through a standard browser can now just as easily be accessed by users from around the world as by users from the business department itself. As a bonus – the development of the APEX application is also done in the cloud – with no special demands on the location or the enterprise access privileges of the More >
Create simple Java application to post JSON message to CometD Bayeux Channel using Apache HttpClient and Maven style NetBeans project0
The objective discussed in this article is to post messages to a CometD Bayeux Channel with a standalone Java Class – without dependencies on CometD. For example to control from Java the Slideshow introduced in the synchronized Slideshow demo application created using CometD (see previous articles Push based synchronized Slideshow demo application implemented using CometD and jQuery running on Tomcat and Publishing to CometD Bayeux Channel from inside the Oracle Database â€“ PL/SQL based push to CometD Web Client ).
This article describes the creation of a simple Java Class leveraging Apache HttpClient to post HTTP requests (JSON messages) to a CometD Bayeux Channel. The main point is to show working code with the lest dependencies, not an optimal program (it is far from optimal). The article demonstrates how NetBeans and Maven conspire here to make the task as simple as possible. The Maven support in NetBeans allows me to simply create a new Maven style project of (arche)type Java Application.
Push-based synchronized slideshow web application – implemented using WebSockets and Kaazing WebSocket Gateway9
In the last few articles, I have discussed downloading, installing and running demos for a number of different tools, frameworks and libraries that support push-style (web) applications in one way or another. I have looked into ‘classic’ comet with Grizzly, Atmosphere and CometD as well as ADF Active Data Service and WebLogic Pub/Sub (Bayeux) Channels. I have also looked to WebSockets with jWebSocket, again Atmosphere and CometD and also with Kaazing. I intend to now take a closer look at some of these frameworks, by taking a simple push-style application and implementing it using each of these frameworks. The functionality I will be implementing is simple:
- the selection of the image is communicated to the server (background WebSocket based or alternatively regular AJAX)Comet (Bayeux)/Long Poll style)
- the server informs all connected clients about the selected image through a pushed message (background WebSocket based or alternatively Comet (Bayeux)/Long Poll style); these clients all synchronize that slide selection
- a Java (server side) component can also connect to the More >
Absolutely Typical – The whole story on Types and how they power PL/SQL Interoperability (UKOUG, 2011)4
This presentation will hopefully convince database developers that types in the Oracle Database are worth their salt – and more. With the recent improvements in 11gR2, the pieces are available to complete the puzzle of structured and modern programming with a touch of OO and more importantly to create a decoupled, reusable API that exposes services based on tables and views to clients that speak SQL, AQ, PL/SQL, Types, XML or RESTful, through SQL*Net, JDBC or HTTP.
This session shows through many demonstrations how types and collections are defined, how they are used between SQL and PL/SQL and how they can be converted to and from XML and JSON and how they drive Native WebServices as well as RESTful services based on the Embedded PL/SQL Gateway. Everyone doing PL/SQL programming will benefit immediately from this session. Every Database Developer should be aware of Types and Collections. For structured programming, for optimal SQL to PL/SQL integration and for interoperability to client application. This session introduces Types and Collections, their OO capabilities, the conversion to XML and JSON, their use in Native and RESTful WebServices and the pivotal role they can play in More >
This very brief article demonstrates how a fairly complex, nested JSON document can be created using a single SQL query. The main features used in the SQL statement are the WITH clause to define the inline views per object (Department, Manager, Employee), Scalar Subquery to retrieve the result from an inline view as string into the overall JSON string and LISTAGG to collect multiple elements into a JSON list.
The article shows a very simple application of this JSON creation through a simple HTML page – served by a PL/SQL package. This page does not contain any data. Right after loading, the onLoad event triggers a listener that invokes – through AJAX – the PL/SQL package’s other procedure. This procedure returns the JSON object – courtesy of that fabulous SQL query – and uses it to write the company details on the fly into the page.
No JDBC based data retrieval in Java applications – RESTstyle, JSON formatted HTTP based interaction from Java to Database1
This article demonstrates how Java application can query data from relational databases (well, in this case more specifically the Oracle RDBMS) without the use of plain old JDBC but instead through a simple HTTP interaction with a RESTful service that returns the data in JSON format.
In this way, issues with JDBC drivers, database connections, data sources and firewall and other network complications are avoided and the Java application does not contain a single bit of SQL.
This article will demonstrate how easy it is to set up the RESTful API from the database – using Oracle’s dbms_epg package – and how this API can be accessed from Java using JAX-RS (Jersey) and the json-lib utility library.
This topic is one of many to be discussed in Friday’s (4th February) Masterclass on Leveraging the Oracle Database in Java Application (some seats are available – go to http://www.amis.nl/trainingen/oracle-database-in-java-applications for registration and details).