Jackson serialization errors in Spring REST APIs are among the most frustrating runtime failures — your controller compiles fine, your tests pass, and then at runtime a perfectly ordinary @GetMapping blows up with a cryptic 500. Let’s work through every common cause so you can get your API responding again.

TLDR — Most Common Fix

Add public getters to your model class. Jackson serializes objects by looking for getX() methods, not fields. If your class has private fields and no getters, Jackson has nothing to work with.

// Add this to your model (or use @Data from Lombok)
public String getName() { return name; }
public int getAge() { return age; }

What the Error Actually Looks Like

Most Jackson serialization failures in Spring surface as one of two exception chains in your logs:

org.springframework.http.converter.HttpMessageNotWritableException:
  Could not write JSON: No serializer found for class com.example.User
  and no properties discovered to create BeanSerializer

Caused by: com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
  No serializer found for class com.example.User and no properties discovered
  to create BeanSerializer (to avoid exception, disable
  SerializationFeature.FAIL_ON_EMPTY_BEANS)

Or, if you have bidirectional relationships:

com.fasterxml.jackson.databind.JsonMappingException:
  Infinite recursion (StackOverflowError) (through reference chain:
  com.example.Order["customer"]->com.example.Customer["orders"]->...)

Both exceptions come from Jackson’s ObjectMapper — the component Spring uses under the hood to convert your Java objects to JSON. Use Debugly’s stack trace formatter to clean up these nested exception chains and pinpoint the exact line that’s failing.

Diagnostic Steps

Before jumping to solutions, read the exception message carefully. It tells you almost everything:

  1. “No serializer found” → Jackson can’t read your class’s properties. Go to Cause #1.
  2. “Infinite recursion (StackOverflowError)” → Circular reference between objects. Go to Cause #2.
  3. “Java 8 date/time type java.time.LocalDate not supported by default” → Missing JavaTimeModule. Go to Cause #3.
  4. “No suitable constructor found” on a @RequestBody → Deserialization issue, not serialization. Go to Cause #4.
  5. “Could not write JSON: failed to lazily initialize a collection” → Hibernate proxy not initialized. Go to Cause #5.

Cause #1: Missing Getters on the Model Class

This is by far the most common cause. Jackson’s default serialization strategy — called BeanSerializer — works by introspecting JavaBeans-style getter methods. It does not read fields directly (unless you configure it to).

So a class like this will fail:

// ❌ This will cause "No serializer found"
public class User {
    private String name;
    private int age;
    // no getters!
}

When Spring tries to serialize a User to JSON, Jackson finds zero properties and throws InvalidDefinitionException.

Fix 1a — Add explicit getters:

// ✅ Jackson can now serialize this
public class User {
    private String name;
    private int age;

    public String getName() { return name; }
    public int getAge() { return age; }
}

Fix 1b — Use Lombok @Data or @Getter:

import lombok.Data;

@Data
public class User {
    private String name;
    private int age;
    // Lombok generates getters, setters, equals, hashCode, toString
}

Fix 1c — Tell Jackson to use fields instead (use sparingly):

import com.fasterxml.jackson.annotation.JsonAutoDetect;

@JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.ANY)
public class User {
    private String name;
    private int age;
}

This last option works but goes against Jackson’s design philosophy. It’s better to add getters or use Lombok, especially if you’re already using Spring Data JPA where proper accessors matter.

Cause #2: Circular References / Infinite Recursion

If you have a bidirectional JPA relationship, like an Order that references a Customer and a Customer that has a list of Order objects, Jackson will happily follow each reference in an infinite loop until the JVM throws a StackOverflowError.

// ❌ These two classes will cause infinite recursion when serialized
@Entity
public class Customer {
    private Long id;
    private String name;
    private List<Order> orders; // points back to Order
}

@Entity
public class Order {
    private Long id;
    private String product;
    private Customer customer; // points back to Customer
}

Fix 2a — Use @JsonIgnore on one side:

This is the quickest fix. Put @JsonIgnore on the “back” side of the relationship — typically the child’s reference to the parent.

@Entity
public class Order {
    private Long id;
    private String product;

    @JsonIgnore
    private Customer customer; // Jackson will skip this field
}

Fix 2b — Use @JsonManagedReference and @JsonBackReference:

This is cleaner because it tells Jackson explicitly which direction to serialize:

@Entity
public class Customer {
    private Long id;
    private String name;

    @JsonManagedReference  // This side gets serialized
    private List<Order> orders;
}

@Entity
public class Order {
    private Long id;
    private String product;

    @JsonBackReference  // This side is skipped
    private Customer customer;
}

Fix 2c — Use a DTO (best practice):

In production APIs, the cleanest solution is to never serialize your JPA entities directly. Create a plain DTO class with only the fields you want to expose:

public class OrderDto {
    private Long id;
    private String product;
    private Long customerId; // just the ID, no circular reference
    private String customerName;

    // constructors, getters...
}

// In your controller:
@GetMapping("/orders/{id}")
public OrderDto getOrder(@PathVariable Long id) {
    Order order = orderService.findById(id);
    return new OrderDto(order.getId(), order.getProduct(),
                        order.getCustomer().getId(),
                        order.getCustomer().getName());
}

DTOs give you full control over your API contract and prevent leaking internal database structure. They’re the right call on any serious project.

Cause #3: Java 8 Date/Time Types Not Configured

If your model uses LocalDate, LocalDateTime, ZonedDateTime, or other java.time types, you’ll see this error out of the box:

com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
  Java 8 date/time type `java.time.LocalDate` not supported by default:
  add Module "com.fasterxml.jackson.datatype:jackson-datatype-jsr310"
  to enable handling

Jackson doesn’t support java.time types by default — you need the jackson-datatype-jsr310 module. In Spring Boot, this module is on the classpath automatically (it’s part of spring-boot-starter-web), but it still needs to be registered.

Fix 3a — Register JavaTimeModule globally:

If you’re using Spring Boot, the easiest fix is a single property in application.properties:

spring.jackson.serialization.write-dates-as-timestamps=false

This also auto-registers JavaTimeModule when Spring Boot detects it on the classpath.

Fix 3b — Configure the ObjectMapper bean manually:

@Configuration
public class JacksonConfig {

    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper mapper = new ObjectMapper();
        mapper.registerModule(new JavaTimeModule());
        mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
        return mapper;
    }
}

Fix 3c — Use @JsonSerialize on individual fields:

If you only need to fix one or two fields without touching the global config:

import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;

public class Event {
    @JsonSerialize(using = LocalDateSerializer.class)
    @JsonDeserialize(using = LocalDateDeserializer.class)
    private LocalDate eventDate;
}

Cause #4: Deserialization Failures on @RequestBody

If the error happens when Spring is reading JSON (not writing it), you’re dealing with deserialization. The most common reason: no default no-argument constructor.

com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
  Cannot construct instance of `com.example.CreateUserRequest`
  (no Creators, like default constructor, exist)

// ❌ Jackson needs a no-arg constructor to create this object
public class CreateUserRequest {
    private final String name;
    private final String email;

    public CreateUserRequest(String name, String email) {
        this.name = name;
        this.email = email;
    }
}

Fix 4a — Add a no-arg constructor:

public class CreateUserRequest {
    private String name;
    private String email;

    public CreateUserRequest() {} // Jackson needs this

    public CreateUserRequest(String name, String email) {
        this.name = name;
        this.email = email;
    }

    // getters and setters...
}

Fix 4b — Use @JsonCreator with constructor parameters:

If you want an immutable class, annotate the constructor Jackson should use:

public class CreateUserRequest {
    private final String name;
    private final String email;

    @JsonCreator
    public CreateUserRequest(
            @JsonProperty("name") String name,
            @JsonProperty("email") String email) {
        this.name = name;
        this.email = email;
    }

    public String getName() { return name; }
    public String getEmail() { return email; }
}

Fix 4c — Use Lombok’s @Builder with @Jacksonized:

import lombok.Builder;
import lombok.Value;
import lombok.extern.jackson.Jacksonized;

@Value
@Builder
@Jacksonized
public class CreateUserRequest {
    String name;
    String email;
}

Cause #5: Hibernate Lazy-Loading Proxy Serialization

This one shows up when you serialize a JPA entity that has uninitialized lazy associations. Hibernate wraps relationships in proxy objects, and Jackson doesn’t know how to handle them.

com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
  No serializer found for class org.hibernate.proxy.pojo.bytebuddy.ByteBuddyInterceptor

Or you might see:

org.hibernate.LazyInitializationException:
  failed to lazily initialize a collection, could not initialize proxy - no Session

Fix 5a — Add hibernate5-module (or hibernate6-module):

<!-- For Spring Boot with Hibernate 6 -->
<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-hibernate6</artifactId>
</dependency>

@Configuration
public class JacksonConfig {

    @Bean
    public Module hibernateModule() {
        return new Hibernate6Module();
    }
}

This tells Jackson to serialize null for uninitialized lazy proxies instead of crashing.

Fix 5b — Use @JsonIgnoreProperties on the entity:

@Entity
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class Customer {
    // ...
}

Fix 5c — Use DTOs (the real fix):

Honestly, if you’re hitting Hibernate proxy serialization errors, that’s a signal to stop serializing entities directly. See the DTO example in Cause #2 — it eliminates this entire class of problems.

Check out our post on Spring JPA LazyInitializationException for a deeper dive into Hibernate session issues.

Still Not Working?

A few less common situations that catch developers off guard:

Private inner classes: If your model class is a non-static inner class or a private class, Jackson can’t access it even with getters. Make it a top-level class or public static.

Enum serialization: By default, Jackson serializes enums by their name() value. If you’re getting unexpected enum output, use @JsonValue on a getter method in the enum.

public enum Status {
    ACTIVE, INACTIVE;

    @JsonValue
    public String toJson() {
        return name().toLowerCase();
    }
}

Multiple ObjectMapper beans: If you defined a custom ObjectMapper bean but Spring Boot also auto-configured one, Jackson might be using a different instance than you expect. Use @Primary on your custom bean, or extend WebMvcConfigurer to apply configuration through configureMessageConverters.

Jackson version conflicts: If you’re using a Spring Boot parent POM but overriding Jackson versions in your pom.xml, mismatched module versions (e.g., jackson-databind 2.15 with jackson-datatype-jsr310 2.13) can cause serializer lookup failures. Let Spring Boot manage Jackson versions unless you have a specific reason not to.

Use Debugly’s stack trace formatter to paste the full exception chain and identify exactly which class is causing the problem. Related Spring exceptions like BeanCreationException and NoSuchBeanDefinitionException can sometimes appear alongside Jackson errors when context startup itself is failing.

Summary Checklist

When you hit a Jackson serialization error in Spring, work through this list:

  • [ ] Model has public getters — or uses Lombok @Data/@Getter
  • [ ] No circular references — use @JsonIgnore, @JsonManagedReference, or DTOs
  • [ ] Java 8 date types configured — JavaTimeModule registered, write-dates-as-timestamps=false
  • [ ] Deserialization has a no-arg constructor — or uses @JsonCreator
  • [ ] Hibernate module registered — if serializing JPA entities with lazy associations
  • [ ] No multiple conflicting ObjectMapper beans — use @Primary if needed
  • [ ] Jackson versions consistent — managed by Spring Boot BOM

If you’re spending time squinting at raw, nested stack traces, paste them into Debugly’s stack trace formatter — it highlights the root cause and filters out the Spring framework noise so you can focus on your code.

Jackson errors are annoying precisely because the root cause is often something trivial — a missing getter, a forgotten annotation, or a module that wasn’t registered. Once you know the patterns, you’ll spot them in seconds. Bookmark this guide for the next time a 500 surprises you right before a demo.