Spring Batch Simple Example Part 3

In this post I will explain how to combine the reader and writer in a job and how to run the job. We define a job which will transfer the employee records from one file to another file in batches. <batch:job id=”importEmployees”> <batch:step id=”readWriteEmployees”> <batch:tasklet> <batch:chunk reader=”reader” writer=”writer” commit-interval=”50″/> </batch:tasklet> </batch:step> </batch:job> <bean id=”transactionManager” class=”org.springframework.batch.support.transaction.ResourcelessTransactionManager”…

Spring Batch Simple Example Part 2

In this post, I will explain how to write the employee objects created in the reading process to a file. To write the list of employee records in batches, we need to create an instance of org.springframework.batch.item.file.FlatFileItemWriter. It takes two information 1) the resource file where the information has to be written 2) An instance…

Spring Batch Simple Example Part 1

In this post and next post, I will introduce Spring Batch to you with a simple example. Spring batch is an open source framework useful for exporting data from source to destination in batches. The framework is very useful for batch applications. Reading data In our example, we will read employee records and move them…

Creating filters in JAX-RS

This post explains how to create filters in JAX-RS code. The filters can be placed before and after the web resource. So we can use the filters for 1) modifying the request 2) restricting certain requests from reaching the webresource 3) modifying the response In the below code I have created a custom filter, which…

BeanParam annotation example

This post will explain the use of BeanParam annotation in JAX-RS with an example. The purpose of BeanParam annotation is to consolidate all the user input (i.e., input through QueryParam, HeaderParam, FormParam, etc) and inject into a given class instance variables. Below is an example of webresource whose only method “retrieveRecord1” has a parameter annotated…

Mapping exceptions to Response in JAX-RS

In JAX-RS, we can map exceptions to a Response. This will be useful in hiding the exceptions from the client of JAX-RS web services. Below is an example showing how to map exceptions to appropriate responses. First we need to implement ExceptionMapper interface as shown below. Here we want to map NullPointer exception to Internal…

Configuring the Jsonb instance

From the previous posts we can see that an instance of Jsonb is used for serialization/deserialization of java objects to/from json format. We can configure the Jsonb instance by creating an instance of JsonbConfig. By default jsonb implementation provider must support the following properties to be configured. jsonb.to.json.formatted – java.lang.Boolean Controls whether or not the…