java 65 lines · 6 steps

Filtering JSON fields with @JsonView in Spring

One response class serializes different field sets per endpoint by tagging fields with view interfaces.

Explained by highlit
Spring Intermediate serialization json-view access-control dto jackson
1public class Views {
2 public interface Public {}
3 public interface Internal extends Public {}
4}
5 
6public class UserResponse {
7 
8 @JsonView(Views.Public.class)
9 private final Long id;
10 
11 @JsonView(Views.Public.class)
12 private final String username;
13 
14 @JsonView(Views.Public.class)
15 private final String displayName;
16 
17 @JsonView(Views.Internal.class)
18 private final String email;
19 
20 @JsonView(Views.Internal.class)
21 private final Instant lastLoginAt;
22 
23 @JsonView(Views.Internal.class)
24 private final boolean emailVerified;
25 
26 public UserResponse(User user) {
27 this.id = user.getId();
28 this.username = user.getUsername();
29 this.displayName = user.getDisplayName();
30 this.email = user.getEmail();
31 this.lastLoginAt = user.getLastLoginAt();
32 this.emailVerified = user.isEmailVerified();
33 }
34 
35 public Long getId() { return id; }
36 public String getUsername() { return username; }
37 public String getDisplayName() { return displayName; }
38 public String getEmail() { return email; }
39 public Instant getLastLoginAt() { return lastLoginAt; }
40 public boolean isEmailVerified() { return emailVerified; }
41}
42 
43@RestController
44@RequestMapping("/api/users")
45public class UserController {
46 
47 private final UserService userService;
48 
49 public UserController(UserService userService) {
50 this.userService = userService;
51 }
52 
53 @JsonView(Views.Public.class)
54 @GetMapping("/{id}")
55 public UserResponse getPublicProfile(@PathVariable Long id) {
56 return new UserResponse(userService.findById(id));
57 }
58 
59 @JsonView(Views.Internal.class)
60 @GetMapping("/{id}/details")
61 @PreAuthorize("hasRole('ADMIN')")
62 public UserResponse getFullProfile(@PathVariable Long id) {
63 return new UserResponse(userService.findById(id));
64 }
65}
01 / 01
STEP 01

Walkthrough

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Three takeaways
  1. 1Marker interfaces let one DTO expose different field subsets without duplicate classes.
  2. 2Extending a base view interface makes internal views inherit every public field automatically.
  3. 3Pairing @JsonView with @PreAuthorize keeps sensitive fields out of both the payload and unauthorized hands.

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