{"id":124728,"date":"2024-07-16T12:55:50","date_gmt":"2024-07-16T09:55:50","guid":{"rendered":"https:\/\/www.javacodegeeks.com\/?p=124728"},"modified":"2024-07-16T12:55:52","modified_gmt":"2024-07-16T09:55:52","slug":"implementing-json-item-reader-and-writer-in-spring-batch","status":"publish","type":"post","link":"https:\/\/www.javacodegeeks.com\/implementing-json-item-reader-and-writer-in-spring-batch.html","title":{"rendered":"Implementing JSON Item Reader and Writer in Spring Batch"},"content":{"rendered":"

Spring Batch<\/a> is a popular framework for building batch applications in Java. One of the key features of Spring Batch<\/a> is its ability to read and write data in various formats, including JSON. In this article, we will explore how to use Spring Batch to read and write JSON data using the JsonItemReader<\/code> and JsonFileItemWriter<\/code> classes.<\/p>\n

1. Project Setup<\/h2>\n

Let’s begin by creating a Maven project. Below is the pom.xml<\/code> file with all the required dependencies included.<\/p>\n

\n    <dependencies>\n        <dependency>\n            <groupId>org.springframework.boot<\/groupId>\n            <artifactId>spring-boot-starter-batch<\/artifactId>\n        <\/dependency>\n        <dependency>\n            <groupId>org.springframework.boot<\/groupId>\n            <artifactId>spring-boot-starter-web<\/artifactId>\n        <\/dependency>\n        <dependency>\n            <groupId>com.fasterxml.jackson.core<\/groupId>\n            <artifactId>jackson-databind<\/artifactId>\n        <\/dependency>\n    <\/dependencies>\n<\/pre>\n
1.1 JSON Example File<\/h3>\n
Let’s create an example JSON file data.json<\/code> that contains a list of users.<\/p>\n
\n[\n  {\n    \"id\": 1,\n    \"name\": \"John Franklin\",\n    \"email\": \"john.franklin@jcg.com\"\n  },\n  {\n    \"id\": 2,\n    \"name\": \"Thomas Smith\",\n    \"email\": \"thomas.smith@jcg.com\"\n  },\n    {\n    \"id\": 3,\n    \"name\": \"Adams Jefferson\",\n    \"email\": \"adams.jefferson@jcg.com\"\n  }\n]\n<\/pre>\n
1.2 Model Class<\/h3>\n
Create a User<\/code> class to represent the data in the JSON file.<\/p>\n
\npublic class User {\n    \n    private int id;\n    private String name;\n    private String email;\n\n    public int getId() {\n        return id;\n    }\n\n    public void setId(int id) {\n        this.id = id;\n    }\n\n    public String getName() {\n        return name;\n    }\n\n    public void setName(String name) {\n        this.name = name;\n    }\n\n    public String getEmail() {\n        return email;\n    }\n\n    public void setEmail(String email) {\n        this.email = email;\n    }   \n}\n<\/pre>\n
2. JSON Item Reader Example<\/h2>\n
To read the JSON data using Spring Batch, we need to create a JsonItemReader<\/code> bean and configure it to read the JSON file. <\/p>\n
In our example, we will use the JsonItemReaderBuilder<\/code> to create an ItemReader<\/code> that reads User<\/code> objects from our JSON file (data.json<\/code>). We will also use the @StepScope<\/code> annotation to ensure that the reader is instantiated within the scope of a step, allowing for dynamic step-based configurations.
 
<\/div> <\/div><\/p>\n
\n@Configuration\npublic class JsonItemReaderConfig {\n\n    @Bean\n    @StepScope\n    public JsonItemReader<User> jsonItemReader() {\n        ObjectMapper objectMapper = new ObjectMapper();\n\n        return new JsonItemReaderBuilder<User>()\n                .jsonObjectReader(new JacksonJsonObjectReader<>(User.class))\n                .resource(new ClassPathResource(\"data.json\"))\n                .name(\"jsonItemReader\")\n                .build();\n    }\n}\n\n<\/pre>\n
In the code above:<\/p>\n