ClaimsPrincipal序列化为Json的正确姿势

第二步理解三者的关系1.Claim声明的基本单元职责表示一个键值对形式的声明如name Alice、role Admin。不仅包含类型Type和值Value还携带元数据如ValueType值的数据类型如字符串、整数等默认为string。Issuer声明的颁发者如https://login.microsoft.com。OriginalIssuer原始颁发者用于联合身份场景。Properties可扩展的键值对字典用于存储额外信息。特点不可变性一旦创建其核心属性Type/Value通常不可更改。轻量级设计为数据载体无业务逻辑。语义丰富通过标准声明类型如ClaimTypes.Name、ClaimTypes.Role实现互操作性。2.ClaimsIdentity代表一个身份Identity职责封装一组相关的Claim构成一个完整的身份视图。提供身份的上下文信息AuthenticationType认证方式如Cookies、JwtBearer。IsAuthenticated是否已通过认证依赖AuthenticationType非空。Name通常映射自NameClaimType类型的声明默认为ClaimTypes.Name。RoleClaimType用于角色判断的声明类型默认为ClaimTypes.Role。关键行为AddClaim(Claim)动态添加声明常用于中间件或策略授权。FindFirst(string type)查找首个匹配类型的声明。HasClaim(...)检查是否存在特定声明。设计思想一个主体如用户可以有多个身份例如本地登录身份 社交账号身份。支持多身份源如 Windows 身份、JWT 身份、自定义身份。3.ClaimsPrincipal代表一个安全主体Principal职责代表当前用户或系统实体是安全上下文的顶层容器。包含一个或多个ClaimsIdentity对象通过Identities集合。提供便捷属性访问主身份Identity属性返回第一个ClaimsIdentity。聚合所有身份的声明Claims属性返回所有ClaimsIdentity中声明的并集。关键行为IsInRole(string role)检查是否属于某角色依据RoleClaimType声明。FindFirst(string claimType)跨所有身份查找首个匹配声明。HasClaim(...)检查是否存在指定声明。与线程上下文集成在 ASP.NET Core 中HttpContext.User的类型就是ClaimsPrincipal。可通过Thread.CurrentPrincipal.NET Framework或IHttpContextAccessor.NET Core访问。4. 三者协作关系ClaimsPrincipal │ ├── ClaimsIdentity #1 (e.g., from JWT) │ ├── Claim: { Typename, ValueAlice } │ ├── Claim: { Typerole, ValueAdmin } │ └── Claim: { Typeemail, Valuealiceexample.com } │ └── ClaimsIdentity #2 (e.g., from external provider) ├── Claim: { Typesub, Value12345 } └── Claim: { Typeidp, ValueGoogle }第三步设计序列化模型DTO理解了ClaimsPrincipal的内部结构后我们需要设计可序列化的 DTO 来承载这些数据。关键是要保留足够的信息以便在反序列化时能够完整还原原始对象。1. 设计原则在设计序列化模型时我们需要遵循以下原则1.1 完整性Completeness保留所有关键信息确保反序列化后的对象与原始对象等价Claim的所有核心属性Type、Value、ValueType、Issuer、OriginalIssuer、PropertiesClaimsIdentity的认证上下文AuthenticationType、NameClaimType、RoleClaimTypeClaimsPrincipal的多身份支持Identities 集合1.2 可序列化性Serializability使用简单类型string、int、bool 等和标准集合List、Dictionary避免接口类型、只读属性、私有构造函数等不友好的序列化特性兼容主流序列化器System.Text.Json、Newtonsoft.Json1.3 可读性Readability生成的 JSON 应当清晰易读方便调试和日志记录{ identities: [ { authenticationType: Bearer, nameClaimType: http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name, roleClaimType: http://schemas.microsoft.com/ws/2008/06/identity/claims/role, claims: [ { type: name, value: Alice, valueType: http://www.w3.org/2001/XMLSchema#string, issuer: LOCAL AUTHORITY } ] } ] }2. DTO 类设计2.1 ClaimDtopublic class ClaimDto { /// summary /// 声明类型如 name、role、email /// /summary public string Type { get; set; } string.Empty; /// summary /// 声明值 /// /summary public string Value { get; set; } string.Empty; /// summary /// 值的数据类型默认为 XMLSchema#string /// /summary public string ValueType { get; set; } ClaimValueTypes.String; /// summary /// 声明颁发者 /// /summary public string Issuer { get; set; } ClaimsIdentity.DefaultIssuer; /// summary /// 原始颁发者联合身份场景 /// /summary public string OriginalIssuer { get; set; } ClaimsIdentity.DefaultIssuer; /// summary /// 自定义属性集合 /// /summary public Dictionarystring, string? Properties { get; set; } /// summary /// 从 Claim 创建 DTO /// /summary public static ClaimDto FromClaim(Claim claim) { var dto new ClaimDto { Type claim.Type, Value claim.Value, ValueType claim.ValueType, Issuer claim.Issuer, OriginalIssuer claim.OriginalIssuer }; // 仅在有自定义属性时才序列化 if (claim.Properties.Count 0) { dto.Properties new Dictionarystring, string(claim.Properties); } return dto; } /// summary /// 转换为 Claim 对象 /// /summary public Claim ToClaim() { var claim new Claim(Type, Value, ValueType, Issuer, OriginalIssuer); // 还原自定义属性 if (Properties ! null) { foreach (var prop in Properties) { claim.Properties[prop.Key] prop.Value; } } return claim; } }2.2 ClaimsIdentityDtopublic class ClaimsIdentityDto { /// summary /// 认证类型如 Bearer、Cookies /// /summary public string? AuthenticationType { get; set; } /// summary /// 用于标识用户名的声明类型 /// /summary public string NameClaimType { get; set; } ClaimsIdentity.DefaultNameClaimType; /// summary /// 用于标识角色的声明类型 /// /summary public string RoleClaimType { get; set; } ClaimsIdentity.DefaultRoleClaimType; /// summary /// 声明集合 /// /summary public ListClaimDto Claims { get; set; } new(); /// summary /// 从 ClaimsIdentity 创建 DTO /// /summary public static ClaimsIdentityDto FromClaimsIdentity(ClaimsIdentity identity) { return new ClaimsIdentityDto { AuthenticationType identity.AuthenticationType, NameClaimType identity.NameClaimType, RoleClaimType identity.RoleClaimType, Claims identity.Claims.Select(ClaimDto.FromClaim).ToList() }; } /// summary /// 转换为 ClaimsIdentity 对象 /// /summary public ClaimsIdentity ToClaimsIdentity() { var claims Claims.Select(c c.ToClaim()).ToList(); return new ClaimsIdentity( claims, AuthenticationType, NameClaimType, RoleClaimType ); } }2.3 ClaimsPrincipalDtopublic class ClaimsPrincipalDto { /// summary /// 身份集合 /// /summary public ListClaimsIdentityDto Identities { get; set; } new(); /// summary /// 从 ClaimsPrincipal 创建 DTO /// /summary public static ClaimsPrincipalDto FromClaimsPrincipal(ClaimsPrincipal principal) { return new ClaimsPrincipalDto { Identities principal.Identities .Select(ClaimsIdentityDto.FromClaimsIdentity) .ToList() }; } /// summary /// 转换为 ClaimsPrincipal 对象 /// /summary public ClaimsPrincipal ToClaimsPrincipal() { var identities Identities.Select(i i.ToClaimsIdentity()).ToList(); return new ClaimsPrincipal(identities); } }3. 使用示例3.1 序列化using System.Text.Json; // 获取当前用户的 ClaimsPrincipal var principal httpContext.User; // 转换为 DTO var dto ClaimsPrincipalDto.FromClaimsPrincipal(principal); // 序列化为 JSON var json JsonSerializer.Serialize(dto, new JsonSerializerOptions { WriteIndented true, // 格式化输出 DefaultIgnoreCondition JsonIgnoreCondition.WhenWritingNull // 忽略 null 值 }); // 记录到日志或存储 logger.LogInformation(User principal: {Principal}, json);3.2 反序列化// 从 JSON 还原 var dto JsonSerializer.DeserializeClaimsPrincipalDto(json); // 转换为 ClaimsPrincipal var principal dto?.ToClaimsPrincipal(); // 使用还原的对象 if (principal ! null) { httpContext.User principal; // 或者传递给其他服务 }3.3 实际应用场景场景 1分布式会话存储// 将用户身份序列化后存储到 Redis public async Task SaveUserSession(string sessionId, ClaimsPrincipal principal) { var dto ClaimsPrincipalDto.FromClaimsPrincipal(principal); var json JsonSerializer.Serialize(dto); await redis.StringSetAsync($session:{sessionId}, json, TimeSpan.FromHours(1)); } // 从 Redis 还原用户身份 public async TaskClaimsPrincipal? LoadUserSession(string sessionId) { var json await redis.StringGetAsync($session:{sessionId}); if (json.IsNullOrEmpty) return null; var dto JsonSerializer.DeserializeClaimsPrincipalDto(json); return dto?.ToClaimsPrincipal(); }场景 2微服务间传递身份// 在 HTTP 请求头中传递用户身份 public async TaskHttpResponseMessage CallDownstreamService(ClaimsPrincipal principal) { var dto ClaimsPrincipalDto.FromClaimsPrincipal(principal); var json JsonSerializer.Serialize(dto); var request new HttpRequestMessage(HttpMethod.Get, https://api.example.com/data); request.Headers.Add(X-User-Principal, Convert.ToBase64String(Encoding.UTF8.GetBytes(json))); return await httpClient.SendAsync(request); }场景 3审计日志// 记录用户操作时保存完整的身份信息 public void LogUserAction(ClaimsPrincipal principal, string action, object data) { var dto ClaimsPrincipalDto.FromClaimsPrincipal(principal); var auditLog new { Timestamp DateTime.UtcNow, Principal dto, Action action, Data data }; var json JsonSerializer.Serialize(auditLog, new JsonSerializerOptions { WriteIndented true }); File.AppendAllText(audit.log, json Environment.NewLine); }4. 性能优化建议4.1 按需序列化如果只需要部分信息如用户名和角色可以创建简化版的 DTOpublic class SimplePrincipalDto { public string? Name { get; set; } public Liststring Roles { get; set; } new(); public static SimplePrincipalDto FromClaimsPrincipal(ClaimsPrincipal principal) { return new SimplePrincipalDto { Name principal.Identity?.Name, Roles principal.Claims .Where(c c.Type ClaimTypes.Role) .Select(c c.Value) .ToList() }; } }4.2 缓存序列化结果对于频繁访问的用户身份信息可以缓存序列化结果private readonly ConcurrentDictionarystring, string _cache new(); public string GetCachedJson(ClaimsPrincipal principal) { var key principal.FindFirst(ClaimTypes.NameIdentifier)?.Value ?? string.Empty; return _cache.GetOrAdd(key, _ { var dto ClaimsPrincipalDto.FromClaimsPrincipal(principal); return JsonSerializer.Serialize(dto); }); }4.3 避免序列化敏感信息在序列化前过滤敏感声明public static ClaimsPrincipalDto FromClaimsPrincipalSafe(ClaimsPrincipal principal) { // 定义敏感声明类型 var sensitiveTypes new HashSetstring { password, secret, token }; var dto new ClaimsPrincipalDto { Identities principal.Identities.Select(identity new ClaimsIdentityDto { AuthenticationType identity.AuthenticationType, NameClaimType identity.NameClaimType, RoleClaimType identity.RoleClaimType, Claims identity.Claims .Where(c !sensitiveTypes.Contains(c.Type.ToLowerInvariant())) .Select(ClaimDto.FromClaim) .ToList() }).ToList() }; return dto; }第四步通过自定义 Converter 进行序列化和反序列化上一步我们使用 DTO 模式实现了序列化需要手动转换对象。如果你希望更透明地序列化ClaimsPrincipal可以使用System.Text.Json的自定义转换器JsonConverter。这样可以直接对原始对象进行序列化无需中间的 DTO 层。1. 自定义 Converter 的优势1.1 透明性直接序列化原始类型无需手动转换// DTO 方式需要显式转换 var dto ClaimsPrincipalDto.FromClaimsPrincipal(principal); var json JsonSerializer.Serialize(dto); // Converter 方式直接序列化 var json JsonSerializer.Serialize(principal, options);1.2 集中化序列化逻辑集中在 Converter 中使用时只需配置一次var options new JsonSerializerOptions(); options.Converters.Add(new ClaimsPrincipalConverter()); // 全局使用无需每次转换1.3 类型安全反序列化直接返回目标类型无需额外转换var principal JsonSerializer.DeserializeClaimsPrincipal(json, options); // 直接得到 ClaimsPrincipal不是 DTO2. 实现自定义 Converter2.1 ClaimConverterusing System.Security.Claims; using System.Text.Json; using System.Text.Json.Serialization; public class ClaimConverter : JsonConverterClaim { public override Claim? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) { if (reader.TokenType ! JsonTokenType.StartObject) { throw new JsonException(Expected StartObject token); } string? type null; string? value null; string? valueType ClaimValueTypes.String; string? issuer ClaimsIdentity.DefaultIssuer; string? originalIssuer ClaimsIdentity.DefaultIssuer; Dictionarystring, string? properties null; while (reader.Read()) { if (reader.TokenType JsonTokenType.EndObject) { break; } if (reader.TokenType ! JsonTokenType.PropertyName) { throw new JsonException(Expected PropertyName token); } string propertyName reader.GetString()!; reader.Read(); switch (propertyName.ToLowerInvariant()) { case type: type reader.GetString(); break; case value: value reader.GetString(); break; case valuetype: valueType reader.GetString() ?? ClaimValueTypes.String; break; case issuer: issuer reader.GetString() ?? ClaimsIdentity.DefaultIssuer; break; case originalissuer: originalIssuer reader.GetString() ?? ClaimsIdentity.DefaultIssuer; break; case properties: properties JsonSerializer.DeserializeDictionarystring, string(ref reader, options); break; default: reader.Skip(); break; } } if (string.IsNullOrEmpty(type) || value null) { throw new JsonException(Claim must have Type and Value); } var claim new Claim(type, value, valueType, issuer, originalIssuer); if (properties ! null) { foreach (var prop in properties) { claim.Properties[prop.Key] prop.Value; } } return claim; } public override void Write(Utf8JsonWriter writer, Claim value, JsonSerializerOptions options) { writer.WriteStartObject(); writer.WriteString(type, value.Type); writer.WriteString(value, value.Value); writer.WriteString(valueType, value.ValueType); writer.WriteString(issuer, value.Issuer); writer.WriteString(originalIssuer, value.OriginalIssuer); if (value.Properties.Count 0) { writer.WritePropertyName(properties); JsonSerializer.Serialize(writer, value.Properties, options); } writer.WriteEndObject(); } }2.2 ClaimsIdentityConverterpublic class ClaimsIdentityConverter : JsonConverterClaimsIdentity { public override ClaimsIdentity? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) { if (reader.TokenType ! JsonTokenType.StartObject) { throw new JsonException(Expected StartObject token); } string? authenticationType null; string nameClaimType ClaimsIdentity.DefaultNameClaimType; string roleClaimType ClaimsIdentity.DefaultRoleClaimType; ListClaim? claims null; while (reader.Read()) { if (reader.TokenType JsonTokenType.EndObject) { break; } if (reader.TokenType ! JsonTokenType.PropertyName) { throw new JsonException(Expected PropertyName token); } string propertyName reader.GetString()!; reader.Read(); switch (propertyName.ToLowerInvariant()) { case authenticationtype: authenticationType reader.GetString(); break; case nameclaimtype: nameClaimType reader.GetString() ?? ClaimsIdentity.DefaultNameClaimType; break; case roleclaimtype: roleClaimType reader.GetString() ?? ClaimsIdentity.DefaultRoleClaimType; break; case claims: claims JsonSerializer.DeserializeListClaim(ref reader, options); break; default: reader.Skip(); break; } } return new ClaimsIdentity( claims ?? new ListClaim(), authenticationType, nameClaimType, roleClaimType ); } public override void Write(Utf8JsonWriter writer, ClaimsIdentity value, JsonSerializerOptions options) { writer.WriteStartObject(); writer.WriteString(authenticationType, value.AuthenticationType); writer.WriteString(nameClaimType, value.NameClaimType); writer.WriteString(roleClaimType, value.RoleClaimType); writer.WritePropertyName(claims); JsonSerializer.Serialize(writer, value.Claims.ToList(), options); writer.WriteEndObject(); } }2.3 ClaimsPrincipalConverterpublic class ClaimsPrincipalConverter : JsonConverterClaimsPrincipal { public override ClaimsPrincipal? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) { if (reader.TokenType ! JsonTokenType.StartObject) { throw new JsonException(Expected StartObject token); } ListClaimsIdentity? identities null; while (reader.Read()) { if (reader.TokenType JsonTokenType.EndObject) { break; } if (reader.TokenType ! JsonTokenType.PropertyName) { throw new JsonException(Expected PropertyName token); } string propertyName reader.GetString()!; reader.Read(); if (propertyName.Equals(identities, StringComparison.OrdinalIgnoreCase)) { identities JsonSerializer.DeserializeListClaimsIdentity(ref reader, options); } else { reader.Skip(); } } return new ClaimsPrincipal(identities ?? new ListClaimsIdentity()); } public override void Write(Utf8JsonWriter writer, ClaimsPrincipal value, JsonSerializerOptions options) { writer.WriteStartObject(); writer.WritePropertyName(identities); JsonSerializer.Serialize(writer, value.Identities.ToList(), options); writer.WriteEndObject(); } }3. 使用自定义 Converter3.1 基本使用// 配置序列化选项 var options new JsonSerializerOptions { WriteIndented true, DefaultIgnoreCondition JsonIgnoreCondition.WhenWritingNull, Converters { new ClaimConverter(), new ClaimsIdentityConverter(), new ClaimsPrincipalConverter() } }; // 序列化 var principal httpContext.User; var json JsonSerializer.Serialize(principal, options); // 反序列化 var deserializedPrincipal JsonSerializer.DeserializeClaimsPrincipal(json, options);3.2 全局配置在 ASP.NET Core 中可以全局配置序列化选项// Program.cs 或 Startup.cs builder.Services.ConfigureJsonOptions(options { options.JsonSerializerOptions.Converters.Add(new ClaimConverter()); options.JsonSerializerOptions.Converters.Add(new ClaimsIdentityConverter()); options.JsonSerializerOptions.Converters.Add(new ClaimsPrincipalConverter()); });3.3 创建扩展方法为了更方便使用可以创建扩展方法public static class ClaimsPrincipalExtensions { private static readonly JsonSerializerOptions DefaultOptions new() { WriteIndented true, DefaultIgnoreCondition JsonIgnoreCondition.WhenWritingNull, Converters { new ClaimConverter(), new ClaimsIdentityConverter(), new ClaimsPrincipalConverter() } }; /// summary /// 将 ClaimsPrincipal 序列化为 JSON /// /summary public static string ToJson(this ClaimsPrincipal principal, JsonSerializerOptions? options null) { return JsonSerializer.Serialize(principal, options ?? DefaultOptions); } /// summary /// 从 JSON 反序列化为 ClaimsPrincipal /// /summary public static ClaimsPrincipal? FromJson(string json, JsonSerializerOptions? options null) { return JsonSerializer.DeserializeClaimsPrincipal(json, options ?? DefaultOptions); } /// summary /// 将 ClaimsPrincipal 安全地序列化为 JSON过滤敏感信息 /// /summary public static string ToJsonSafe(this ClaimsPrincipal principal, HashSetstring? sensitiveTypes null) { sensitiveTypes ?? new HashSetstring(StringComparer.OrdinalIgnoreCase) { password, secret, token, apikey }; // 创建过滤后的副本 var filteredIdentities principal.Identities.Select(identity { var filteredClaims identity.Claims .Where(c !sensitiveTypes.Contains(c.Type)) .ToList(); return new ClaimsIdentity( filteredClaims, identity.AuthenticationType, identity.NameClaimType, identity.RoleClaimType ); }).ToList(); var filteredPrincipal new ClaimsPrincipal(filteredIdentities); return filteredPrincipal.ToJson(); } }使用扩展方法// 序列化 var json httpContext.User.ToJson(); // 安全序列化自动过滤敏感信息 var safeJson httpContext.User.ToJsonSafe(); // 反序列化 var principal ClaimsPrincipalExtensions.FromJson(json);4. 实际应用示例4.1 中间件中传递用户身份public class UserPrincipalMiddleware { private readonly RequestDelegate _next; public UserPrincipalMiddleware(RequestDelegate next) { _next next; } public async Task InvokeAsync(HttpContext context) { // 如果请求头包含序列化的用户身份则还原 if (context.Request.Headers.TryGetValue(X-User-Principal, out var principalHeader)) { try { var json Encoding.UTF8.GetString(Convert.FromBase64String(principalHeader!)); var principal ClaimsPrincipalExtensions.FromJson(json); if (principal ! null) { context.User principal; } } catch (Exception ex) { // 记录错误但不中断请求 Console.WriteLine($Failed to deserialize principal: {ex.Message}); } } await _next(context); } }4.2 分布式缓存public class UserSessionService { private readonly IDistributedCache _cache; public UserSessionService(IDistributedCache cache) { _cache cache; } public async Task SaveSessionAsync(string sessionId, ClaimsPrincipal principal) { var json principal.ToJson(); var bytes Encoding.UTF8.GetBytes(json); await _cache.SetAsync(sessionId, bytes, new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow TimeSpan.FromHours(1) }); } public async TaskClaimsPrincipal? GetSessionAsync(string sessionId) { var bytes await _cache.GetAsync(sessionId); if (bytes null) return null; var json Encoding.UTF8.GetString(bytes); return ClaimsPrincipalExtensions.FromJson(json); } }5. DTO vs Converter如何选择5.1 使用 DTO 的场景优点显式转换逻辑清晰可以灵活定制传输的数据结构更容易进行数据验证和转换不依赖特定的序列化框架适用场景API 数据传输需要版本控制和向后兼容跨语言/跨平台通信需要数据脱敏或转换的场景长期存储的数据格式示例// 为前端提供简化的用户信息 public class UserInfoDto { public string UserId { get; set; } public string Name { get; set; } public Liststring Roles { get; set; } public static UserInfoDto FromPrincipal(ClaimsPrincipal principal) { return new UserInfoDto { UserId principal.FindFirst(ClaimTypes.NameIdentifier)?.Value ?? , Name principal.Identity?.Name ?? , Roles principal.Claims .Where(c c.Type ClaimTypes.Role) .Select(c c.Value) .ToList() }; } }5.2 使用 Converter 的场景优点透明序列化使用更简洁保持原始类型无需转换全局配置一次处处可用更好地支持嵌套对象序列化适用场景内部服务通信同技术栈临时缓存和会话存储调试和日志记录需要完整保留对象状态示例// 缓存完整的用户身份 public async Task CacheUserPrincipal(string key, ClaimsPrincipal principal) { // 直接序列化无需转换 var json principal.ToJson(); await _cache.SetStringAsync(key, json, TimeSpan.FromMinutes(30)); }5.3 混合使用在实际项目中两种方式可以共存public class UserService { // 对外 API使用 DTO public UserInfoDto GetPublicUserInfo(ClaimsPrincipal principal) { return UserInfoDto.FromPrincipal(principal); } // 内部缓存使用 Converter public async Task CacheUserSession(string sessionId, ClaimsPrincipal principal) { var json principal.ToJson(); await SaveToCache(sessionId, json); } // 审计日志使用 Converter安全模式 public void LogUserAction(ClaimsPrincipal principal, string action) { var json principal.ToJsonSafe(); _logger.LogInformation(Action: {Action}, User: {User}, action, json); } }6. 性能对比using BenchmarkDotNet.Attributes; using BenchmarkDotNet.Running; [MemoryDiagnoser] public class SerializationBenchmark { private ClaimsPrincipal _principal; private JsonSerializerOptions _options; [GlobalSetup] public void Setup() { var claims new[] { new Claim(ClaimTypes.Name, Alice), new Claim(ClaimTypes.Email, aliceexample.com), new Claim(ClaimTypes.Role, Admin), new Claim(ClaimTypes.Role, User) }; var identity new ClaimsIdentity(claims, Bearer); _principal new ClaimsPrincipal(identity); _options new JsonSerializerOptions { Converters { new ClaimConverter(), new ClaimsIdentityConverter(), new ClaimsPrincipalConverter() } }; } [Benchmark] public string SerializeWithDto() { var dto ClaimsPrincipalDto.FromClaimsPrincipal(_principal); return JsonSerializer.Serialize(dto); } [Benchmark] public string SerializeWithConverter() { return JsonSerializer.Serialize(_principal, _options); } [Benchmark] public ClaimsPrincipal DeserializeWithDto() { var dto ClaimsPrincipalDto.FromClaimsPrincipal(_principal); var json JsonSerializer.Serialize(dto); var deserializedDto JsonSerializer.DeserializeClaimsPrincipalDto(json); return deserializedDto!.ToClaimsPrincipal(); } [Benchmark] public ClaimsPrincipal DeserializeWithConverter() { var json JsonSerializer.Serialize(_principal, _options); return JsonSerializer.DeserializeClaimsPrincipal(json, _options)!; } } // 运行基准测试 // BenchmarkRunner.RunSerializationBenchmark();预期结果Converter 方式通常略快少一次对象转换内存使用相近两者性能差异在大多数场景下可忽略7. 注意事项7.1 空值处理确保 Converter 正确处理 null 值public override void Write(Utf8JsonWriter writer, ClaimsPrincipal? value, JsonSerializerOptions options) { if (value null) { writer.WriteNullValue(); return; } // ... 正常序列化逻辑 }7.2 循环引用虽然 ClaimsPrincipal 结构简单不会出现循环引用但在扩展时需注意var options new JsonSerializerOptions { ReferenceHandler ReferenceHandler.IgnoreCycles, // 处理循环引用 Converters { /* ... */ } };7.3 版本兼容性序列化格式应考虑向后兼容public override ClaimsIdentity? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) { // 为新增字段提供默认值 string nameClaimType ClaimsIdentity.DefaultNameClaimType; // 兼容旧版本 JSON可能缺少某些字段 // ... }