SpringBoot uses LomBok

What is Lombok? It is a method that can help us eliminate the repetitive code that must be written, such as setters, getters, constructors, etc.

First of all, let’s briefly talk about how to install lombok in idea. There are 2 methods:
1. Download it directly from http://plugins.jetbrains.com/ , then put it in the plugins under the idea installation file, and then restart idea
2. In the settings of idea ( windows) or Preferences (mac), find the plugins menu, click Browse repositories, as shown in the figure

Then search for lombok, click download on the right, and restart after the download is complete, as shown in the figure

Create a new project and add lombok dependencies to the pom file. The complete pom is as follows:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.dalaoyang</groupId>
    <artifactId>springboot_lombok</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot_lombok</name>
    <description>springboot_lombok</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.20</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

Create a new User class, this is the class that uses lombok, the code is as follows:

package com.dalaoyang.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * @author dalaoyang
 * @Description
 * @project springboot_learn
 * @package com.dalaoyang
 * @email [email protected]
 * @date 2018/5/7
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {

    private Integer id;
    private String name;
    private String password;
}

Create a new UserNoLombok class, which is the same as the original one. The purpose is to compare the benefits of using lombok. The code is as follows:

package com.dalaoyang.entity;

import java.util.Objects;

/**
 * @author dalaoyang
 * @Description
 * @project springboot_learn
 * @package com.dalaoyang.entity
 * @email [email protected]
 * @date 2018/5/7
 */
public class UserNoLombok {
    private Integer id;
    private String name;
    private String password;

    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 String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public UserNoLombok(Integer id, String name, String password) {
        this.id = id;
        this.name = name;
        this.password = password;
    }


    public UserNoLombok() {
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        UserNoLombok that = (UserNoLombok) o;
        return Objects.equals(id, that.id) &&
                Objects.equals(name, that.name) &&
                Objects.equals(password, that.password);
    }

    @Override
    public int hashCode() {

        return Objects.hash(id, name, password);
    }

    @Override
    public String toString() {
        return "UserNoLombok{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

Then create a new UserController test with the following code:


package com.dalaoyang.controller;

import com.dalaoyang.entity.User;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author dalaoyang
 * @Description
 * @project springboot_learn
 * @package com.dalaoyang.controller
 * @email [email protected]
 * @date 2018/5/7
 */
@RestController
public class UserController {

    @GetMapping("/testUser")
    public User getUser(){
        User user = new User();
        user.setId(1);
        user.setName("dalaoyang");
        user.setPassword("123");
        System.out.println(user.toString());
        return user;
    }
}

Visit http://localhost:8080/testUser as shown in the figure

Introduction to lombok annotations:

@Data 标签，生成getter/setter toString()等方法 
@NonNull : 让你不在担忧并且爱上NullPointerException 
@CleanUp : 自动资源管理：不用再在finally中添加资源的close方法 
@Setter/@Getter : 自动生成set和get方法 
@ToString : 自动生成toString方法 
@EqualsAndHashcode : 从对象的字段中生成hashCode和equals的实现 
@NoArgsConstructor/@RequiredArgsConstructor/@AllArgsConstructor 
自动生成构造方法 
@Data : 自动生成set/get方法，toString方法，equals方法，hashCode方法，不带参数的构造方法 
@Value : 用于注解final类 
@Builder : 产生复杂的构建器api类 
@SneakyThrows : 异常处理（谨慎使用） 
@Synchronized : 同步方法安全的转化 
@Getter(lazy=true) : 
@Log : 支持各种logger对象，使用时用对应的注解，如：@Log4j

Source code download: Da Lao Yang Code Cloud

Personal website: https://www.dalaoyang.cn

SpringBoot uses LomBok

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