你可能不知道的开发小技巧或坑

谁践踏了优雅 2023-06-30 08:41 28阅读 0赞

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5OTk4MDAz_size_16_color_FFFFFF_t_70][]

### Lombok注解 ###

Lombok的`@Accessors(chain = true)`注解链式风格构建

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5OTk4MDAz_size_16_color_FFFFFF_t_70 1][]

#### 实现原理 ####

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5OTk4MDAz_size_16_color_FFFFFF_t_70 2][]

#### Lombok的`@Builder`注解，建造者模式生成构建器 ####

@Builder
    public class User {
        String username;
        String password;
    }
    
    // 建造者模式构建对象
    User u = User.builder().username("用户名").password("密码").build();

##### 实现原理 #####

public class User {
    
        private String username;
        private String password;
    
        public User(String username, String password) {
            this.username = username;
            this.password = password;
        }
    
        public static User.UserBuilder builder(){
            return new User.UserBuilder();
        }
    
        public static class UserBuilder {
    
            private String username;
            private String password;
    
            public User.UserBuilder username(String username){
                this.username = username;
                return this;
            }
    
            public User.UserBuilder password(String password){
                this.password = password;
                return this;
            }
    
            public User build(){
                return new User(this.username, this.password);
            }
        }
    }

### Maven 冲突 ###

使用IDEA插件Maven Helper，查看pom.xml文件，选择Dependency Analyzer，选择Conflicts即可查看冲突的依赖，直接右键选择Exclude即可排除掉冲突或重复的依赖，再点击Refresh-UI刷新检测

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5OTk4MDAz_size_16_color_FFFFFF_t_70 3][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5OTk4MDAz_size_16_color_FFFFFF_t_70 4][]

### 精度丢失 ###

#### 前端Long类型精度丢失 ####

例如：201911200001725439这样一个Long类型数，传给前端后会变成201911200001725440

字段上使用注解：@JSONField(serializeUsing= ToStringSerializer.class)

前后分离项目的时间字段尽量不要使用时间戳存储

@JsonFormat(timezone = "GMT 8", pattern = "yyyy-MM-dd HH:mm:ss")
    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private Date createTime;

前后端时间格式保持一致。

### MySQL数据库远程连接慢 ###

推荐开启`skip_name_resolve`

#### 以上内容皆为本人观点，欢迎大家提出批评和指导，我们一起探讨！ ####

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