MyBatis-Getting Started-Lombok Tool Introduction

Table of contents

problem analysis

lombok

---

problem analysis

In the SpringBoot project, when creating an entity class, although there are only a few member variables in the entity class, the methods such as set/get/toString are fixed and cumbersome

package com.example.pojo;

// 创建实体类User用于封装查询的数据
public class User {
    private Integer id;
    private String name;
    private short age;
    private short gender;

    private String phone;
    // 创建set、get方法


    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public short getAge() {
        return age;
    }

    public void setAge(short age) {
        this.age = age;
    }

    public short getGender() {
        return gender;
    }

    public void setGender(short gender) {
        this.gender = gender;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }
    // 创建toString()方法

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                ", gender=" + gender +
                ", phone='" + phone + '\'' +
                '}';
    }
    // 创建构造方法

    public User(Integer id, String name, short age, short gender, String phone) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.phone = phone;
    }

    public User() {
    }
}

The above problems can be solved by lombok

lombok

• lombok is a Java class library that can automatically generate constructors, getter/setter, equals, hashcode, toString and other methods in the form of annotations, and can automatically generate log variables to simplify Java development and improve efficiency.

  • @Getterand @Setter: Automatically generate getter and setter methods for the class.

  • @ToString: The toString() method of the auto-generated class.

  • @EqualsAndHashCode: Automatically generate the equals() and hashCode() methods of the class.

  • @NoArgsConstructor: Automatically generate a parameterless constructor

  • @RequiredArgsConstructor: Automatically generate constructors for fields that contain final or @NonNull annotations.

  • @AllArgsConstructor: Automatically generate a constructor that includes all fields

  • @Data: Including the combined annotations of @ToString, @EqualsAndHashCode, @Getterand @Setter, excluding the two annotations of no-argument construction and full-argument construction

  • @Builder: Provides a chain call method to create objects

  • @Slf4j: auto-generated logger

  • @Cleanup: Automatically handle resource closing operations, such as releasing files or database connections

  • @Value: Create an immutable class, all fields are final

  • @NonNull: The tag field cannot be empty, and the corresponding null check code will be generated

    • The specific usage code of the annotation is as follows

    • package com.example.pojo;
      
      import lombok.AllArgsConstructor;
      import lombok.Data;
      import lombok.NoArgsConstructor;
      
      // 创建实体类User用于封装查询的数据
      @Data
      @NoArgsConstructor
      @AllArgsConstructor
      public class User {
          private Integer id;
          private String name;
          private short age;
          private short gender;
      
          private String phone;
      }