gson.toJson(object) BigDecimal Precision Lost

Question

When I converting Object to Json, I have a problem with BigDecimal Precision loosing.
Let Say I have Pojo Class with,

public class DummyPojo {
    private BigDecimal amount;
    private String id;
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public BigDecimal getAmount() {
        return amount;
    }
    public void setAmount(BigDecimal amount) {
        this.amount = amount;
    }
} 

Now I am setting value to Pojo then converting to JSON

public static void main(String[] args) {
        BigDecimal big = new BigDecimal("1000.0005");
        JSONObject resultJson = new JSONObject();
        DummyPojo summary = new DummyPojo();
        summary.setId("A001");
        summary.setAmount(big);

        resultJson.put("summary",new Gson().toJson(summary));
        String result = resultJson.toString();
        System.out.println(result);
    }

1st Test - Correct Output

Output -> {"summary":{"amount":1000.0005,"id":"A001"}}

2nd Test - Wrong Output (Lost BigDecimal Precision)

BigDecimal big = new BigDecimal("1234567.5555"); //Changed the value
Output -> {"summary":{"amount":1234567.5,"id":"A001"}}

3rd Test - Wrong Output (Lost BigDecimal Precision)

BigDecimal big = new BigDecimal("100000.0005"); //Changed the value
Output -> {"summary":{"amount":100000,"id":"A001"}}

Amazing that whenever BigDecimal value is higher length then it truncate decimal place as well. What is the problem with json coversion. Would you please provide me the solution?

Answer 1

I think your mixing Java EE 7's JSONObject with GSON's JsonObject. Gson doesn't seem to have the issue you mention:

public static void main(String[] args) {
    BigDecimal big = new BigDecimal("1234567.5555");
    DummyPojo summary = new DummyPojo();
    JsonObject resultJson = new JsonObject(); //this is Gson not Java EE 7
    summary.setId("A001");
    summary.setAmount(big);
    resultJson.addProperty("summary", new Gson().toJson(summary));
    System.out.println(resultJson.toString());
    //Outputs: {"summary":"{\"amount\":1234567.5555,\"id\":\"A001\"}"}
}