I am currently working on a project that involves reading data from a Cassandra table using Java with sparkSession. The goal is to format the output as JSON.
Here is the structure of my database:
CREATE TABLE user (
user_id uuid,
email text,
first_name text,
last_name text,
user_password text,
created_date timestamp,
updated_date timestamp,
PRIMARY KEY (user_id)
) WITH comment = 'List of all registered and active users';
This is the code snippet designed to return the data in JSON format:
public String getAccountData(UUID userid) throws ClassNotFoundException, SQLException {
SparkSession sparkSession = config.getSparkSession();
Account account = new Account();
Encoder<Account> accountEncoder = Encoders.bean(Account.class);
return sparkSession
.read()
.format("org.apache.spark.sql.cassandra")
.options(new HashMap<String, String>() {
{
put("keyspace", "chat");
put("table", "user");
}
})
.load()
.select("first_name", "last_name", "email")
.filter("user_id = '" + userid +"'")
.toJSON()
.as(accountEncoder)
.toString();
}
Below is the Account.java file for reference:
package rest.account;
import java.io.Serializable;
public class Account implements Serializable {
private String user_id;
private String first_name;
private String last_name;
private String email;
public Account(){}
public Account(String user_id, String first_name, String last_name, String email){
this.user_id = user_id;
this.first_name = first_name;
this.last_name = last_name;
this.email = email;
}
public String getId() {
return user_id;
}
public void setId(String user_id) {
this.user_id = user_id;
}
public String getFirstName() {
return first_name;
}
public void setFirstName(String first_name) {
this.first_name = first_name;
}
public String getLastName() {
return last_name;
}
public void setLastName(String lastName) {
this.last_name = last_name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
The error message encountered during execution:
HTTP Status 500 - org.glassfish.jersey.server.ContainerException: org.apache.spark.sql.AnalysisException: cannot resolve '
If you have any insights or suggestions on how to resolve this issue, I would greatly appreciate your assistance!