how to export a list of data to csv file in rest api

Question

I am exporting a list of user records to csv file in my sprig boot REST application. I am using supercsv maven dependency for this. My entity class for User & Address is like below.

User

     Class User{

private String userId;
private String name;
private int age;
private double salary;
private List<Address> addresses;
}

Address

 class Address{

private String id;
private String city;
private String street;
private String country;

}

enter code here

And my main controller class is like below.

@GetMapping("/exportCsv")
public ResponseEntity<?> exportCsv(HttpServletResponse response) {



    try {
    List<User> userList = getUserList();

    String csvFileName = "users.csv";

    response.setContentType("text/csv");

    // creates mock data
    String headerKey = "Content-Disposition";
    String headerValue = String.format("attachment; filename=\"%s\"",
            csvFileName);
    response.setHeader(headerKey, headerValue);


    // write to csv file //

    ICsvBeanWriter csvWriter = new CsvBeanWriter(response.getWriter(),
            CsvPreference.STANDARD_PREFERENCE);

    String[]  user_headings = { "Name", "Age", "Salary" };

    String[] pojoclassPropertyName = { "name", "age", "salary"
            };

    csvWriter.writeHeader(account_headings);

    if(null!=userList && !userList.isEmpty()){
        for (User user : userList) {
            csvWriter.write(user, pojoclassPropertyName);
          }
        }
    csvWriter.close();

    }catch(Exception e) {
        e.printStackTrace();

    }

    return new ResponseEntity<>("successfully export to csv ",HttpStatus.OK);

with this data i can able to export the user name age salary data to csv file. but how could I pass the header for address in user_headings array and corresponding pojoclassPropertyName array mentioned above so that i can able to export all user and user address data to my csv file. kindly suggest me with any working example.

your user class definition is not fully included... – RichieK Feb 21 '19 at 07:32 — RichieK, Feb 21 '19 at 07:32
sorry about that, I have updated the question – prabeen90 Feb 21 '19 at 08:29 — prabeen90, Feb 21 '19 at 08:29

Rajesh Gurusamy · Answer 1 · 2022-11-14T18:13:57.340

As you added other properties (name, age, salary) of User class in the string array pojoclassPropertyName, you have to add the addresses property.

So the declaration should be like below:

String[] pojoclassPropertyName = { "name", "age", "salary", "addresses"};

Then you have to override toString() method in the Address class to return the data of the class address. This can be something like below:

class Address{

private String id;
private String city;
private String street;
private String country;

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}

public String getCity() {
    return city;
}

public void setCity(String city) {
    this.city = city;
}

public String getStreet() {
    return street;
}

public void setStreet(String street) {
    this.street = street;
}

public String getCountry() {
    return country;
}

public void setCountry(String country) {
    this.country = country;
}

@Override
public String toString() {
    return getId() + " " + getStreet() + " " + getCity() + " " + getCountry();
}

}

This will write the addresses in csv file as you return in toString() method and if there is more than one address then it will be written with comma separated.

highlight the commands such as toString() and class names – Harsh Nov 14 '22 at 11:47 — Harsh, Nov 14 '22 at 11:47

how to export a list of data to csv file in rest api

User

Address

1 Answers1