Spring Boot 4 新特性：Jackson 3 ObjectMapper 异常处理简化，无需 try-catch

4.2.3. application.yaml

spring:
  application:
    name: hello-springboot4-jackson

4.2.4. Jackson 依赖

5. 验证过程

5.1. 数据模型准备

创建一个简单的用户值对象：

package com.example.hello.springboot4.jackson.web.vo;

import lombok.Data;
import java.time.LocalDateTime;

@Data
public class User {
    private Long id;
    private String username;
    private String mobilePhone;
    private LocalDateTime createTime;
}

5.2. 测试方法准备

package com.example.hello.springboot4.jackson.web.controller;

import com.example.hello.springboot4.jackson.web.vo.User;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import tools.jackson.databind.ObjectMapper;
import java.time.LocalDateTime;

@Slf4j
@RestController
@RequestMapping("/user")
@RequiredArgsConstructor
public class UserController {
    private final ObjectMapper objectMapper;

    @GetMapping("/test-json-string-to-object")
    public User testJsonStringToObject() {
        String userJson = """ { "id": 1, "mobilePhone": "18612345678", "username": "zhangsan", "createTime": "2025-12-16T23:14:58.0222814" } """;
        // 注意：没有 try-catch 块！
        User user = objectMapper.readValue(userJson, User.class);
        log.info("用户对象：{}", user);
        return user;
    }

    @GetMapping("/test-object-to-json-string")
    public String testObjectToJsonString() {
        User user = new User();
        user.setId(2L);
        user.setUsername("李四");
        user.setMobilePhone("15012345678");
        user.setCreateTime(LocalDateTime.now());
        // 注意：没有 try-catch 块！
        String userJsonString = objectMapper.writeValueAsString(user);
        log.info("用户 JSON 字符串：{}", userJsonString);
        return userJsonString;
    }
}

5.3. readValue() 方法测试

5.3.1. 测试代码

@GetMapping("/test-json-string-to-object")
public User testJsonStringToObject() {
    String userJson = """ { "id": 1, "mobilePhone": "18612345678", "username": "zhangsan", "createTime": "2025-12-16T23:14:58.0222814" } """;
    // 注意：没有 try-catch 块！
    User user = objectMapper.readValue(userJson, User.class);
    log.info("用户对象：{}", user);
    return user;
}

5.3.2. 测试结果

• 请求：GET http://localhost:8080/user/test-json-string-to-object

日志输出：

2025-12-17T23:01:53.681+08:00 INFO 14072 --- [hello-springboot4-jackson][io-8080-exec-10] c.e.h.s.j.web.controller.UserController : 用户对象：User(id=1, username=zhangsan, mobilePhone=18612345678, createTime=2025-12-16T23:14:58.022281400) 

响应：

{"createTime":"2025-12-16T23:14:58.0222814","id":1,"mobilePhone":"18612345678","username":"zhangsan"}

5.4. writeValueAsString() 方法测试

5.4.1. 测试代码

@GetMapping("/test-object-to-json-string")
public String testObjectToJsonString() {
    User user = new User();
    user.setId(2L);
    user.setUsername("李四");
    user.setMobilePhone("15012345678");
    user.setCreateTime(LocalDateTime.now());
    // 注意：没有 try-catch 块！
    String userJsonString = objectMapper.writeValueAsString(user);
    log.info("用户 JSON 字符串：{}", userJsonString);
    return userJsonString;
}

5.4.2. 测试结果

• 请求：GET http://localhost:8080/user/test-object-to-json-string

响应内容是合法的 JSON 字符串：

{"createTime":"2025-12-17T23:07:26.1884855","id":2,"mobilePhone":"15012345678","username":"李四"}

响应：

{"createTime":"2025-12-17T23:07:26.1884855","id":2,"mobilePhone":"15012345678","username":"李四"}

日志输出：

2025-12-17T23:07:26.189+08:00 INFO 14072 --- [hello-springboot4-jackson][nio-8080-exec-2] c.e.h.s.j.web.controller.UserController : 用户 JSON 字符串：{"createTime":"2025-12-17T23:07:26.1884855","id":2,"mobilePhone":"15012345678","username":"李四"}

6. 总结

Spring Boot 4 简化 ObjectMapper 的异常处理，减少了样板代码，使代码更加简洁优雅。对于正在使用或计划升级到 Spring Boot 4 的开发者来说，这是一个值得欢迎的变化。

在实际项目中，我们可以放心地移除那些繁琐的 try-catch 块，让代码更加专注于核心业务逻辑的实现。同时，建议在项目升级过程中，全面测试相关的 JSON 处理逻辑，确保平滑过渡。