How to Parse JSON and Populate a UserAccountBalance Object with Jackson

To parse the JSON and assign its values to a UserAccountBalance object, you can use a JSON parsing library like Jackson. Here's an example of how you can do it:

First, add the Jackson library as a dependency in your project. If you're using Maven, you can add the following dependency to your pom.xml file:

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.12.1</version>
</dependency>

Then, create the UserAccountBalance class with the necessary fields:

public class UserAccountBalance {
    private Long id;
    private Long accountId;
    private BigDecimal balData;
    private String utime;
    private String eventType;
    private String tradeId;
    private String instId;

    // Add getters and setters
}

Finally, you can parse the JSON and assign its values to a UserAccountBalance object:

import com.fasterxml.jackson.databind.ObjectMapper;

public class Main {
    public static void main(String[] args) throws Exception {
        String json = '{
' + 
                '    "arg": {
' + 
                '        "channel": "balance_and_position",
' + 
                '        "uid": "77982378738415879"
' + 
                '    },
' + 
                '    "data": [
' + 
                '        {
' + 
                '            "pTime": "1597026383085",
' + 
                '            "eventType": "snapshot",
' + 
                '            "balData": [
' + 
                '                {
' + 
                '                    "ccy": "BTC",
' + 
                '                    "cashBal": "1",
' + 
                '                    "uTime": "1597026383085"
' + 
                '                }
' + 
                '            ],
' + 
                '            "posData": [
' + 
                '                {
' + 
                '                    "posId": "1111111111",
' + 
                '                    "tradeId": "2",
' + 
                '                    "instId": "BTC-USD-191018",
' + 
                '                    "instType": "FUTURES",
' + 
                '                    "mgnMode": "cross",
' + 
                '                    "posSide": "long",
' + 
                '                    "pos": "10",
' + 
                '                    "ccy": "BTC",
' + 
                '                    "posCcy": "",
' + 
                '                    "avgPx": "3320",
' + 
                '                    "uTime": "1597026383085"
' + 
                '                }
' + 
                '            ],
' + 
                '            "trades": [
' + 
                '                {
' + 
                '                    "instId": "BTC-USD-191018",
' + 
                '                    "tradeId": "2"
' + 
                '                }
' + 
                '            ]
' + 
                '        }
' + 
                '    ]
' + 
                '}'; // Your JSON string

        ObjectMapper objectMapper = new ObjectMapper();
        UserAccountBalance userAccountBalance = objectMapper.readValue(json, UserAccountBalance.class);

        // Access the values
        System.out.println(userAccountBalance.getId());
        System.out.println(userAccountBalance.getAccountId());
        System.out.println(userAccountBalance.getBalData());
        System.out.println(userAccountBalance.getUtime());
        System.out.println(userAccountBalance.getEventType());
        System.out.println(userAccountBalance.getTradeId());
        System.out.println(userAccountBalance.getInstId());
    }
}

Make sure to replace the '...' in the json variable with the actual JSON string you want to parse.