Why Using `success` Instead of `isSuccess` Prevents JSON Serialization Bugs in Java

Background

In everyday development a boolean field is often used to indicate whether a request succeeded, e.g., a

success

flag exposed through an RPC interface.

JavaBeans Naming Rules

The JavaBeans specification defines getters and setters for normal properties as

getPropertyName()

and

setPropertyName(value)

. For boolean properties the getter must be named

isPropertyName()

while the setter remains

setPropertyName(boolean)

.

<code>public &lt;PropertyType&gt; get&lt;PropertyName&gt;();
public void set&lt;PropertyName&gt;(&lt;PropertyType&gt; a);

public boolean is&lt;PropertyName&gt;();
public void set&lt;PropertyName&gt;(boolean m);
</code>

Problem When the Field Itself Is Named isSuccess

If a field is declared as

private boolean isSuccess;

, IDEs often generate a getter named

isSuccess()

and a setter named

setSuccess(boolean)

. This works at compile time but creates ambiguity for JSON‑serialization libraries that rely on JavaBeans introspection.

<code>class Model implements Serializable {
    private static final long serialVersionUID = 1836697963736227954L;
    private boolean isSuccess;

    public boolean isSuccess() { return isSuccess; }
    public void setSuccess(boolean success) { isSuccess = success; }
    public String getHollis() { return "hollischuang"; }
}
</code>

Serialization Differences

The following test serializes a

Model

instance with three popular libraries.

<code>public class BooleanMainTest {
    public static void main(String[] args) throws IOException {
        Model model = new Model();
        model.setSuccess(true);
        System.out.println("Serializable Result With fastjson :" + JSON.toJSONString(model));
        Gson gson = new Gson();
        System.out.println("Serializable Result With Gson :" + gson.toJson(model));
        ObjectMapper om = new ObjectMapper();
        System.out.println("Serializable Result With jackson :" + om.writeValueAsString(model));
    }
}
</code>

Output:

<code>Serializable Result With fastjson :{"hollis":"hollischuang","success":true}
Serializable Result With Gson :{"isSuccess":true}
Serializable Result With jackson :{"success":true,"hollis":"hollischuang"}
</code>

fastjson and Jackson discover the

isSuccess()

method, interpret the property name as

success

, and therefore produce a JSON field

success

. Gson, on the other hand, inspects the field directly and emits

isSuccess

.

Deserialization Mismatch

When the JSON produced by fastjson (or Jackson) is fed back to Gson, Gson looks for a field named

success

, cannot find it, and leaves the boolean at its default value

false

:

<code>public class BooleanMainTest {
    public static void main(String[] args) throws IOException {
        Model model = new Model();
        model.setSuccess(true);
        Gson gson = new Gson();
        System.out.println(gson.fromJson(JSON.toJSONString(model), Model.class));
    }
}
</code>

Result:

<code>Model[isSuccess=false]
</code>

This discrepancy can cause serious production bugs because the object state after a round‑trip is no longer what was originally set.

Recommendation

Define the field as

private boolean success;

and keep the getter

isSuccess()

. This follows the JavaBeans convention correctly, yields the same property name (

success

) for all serialization frameworks, and eliminates the inconsistency.