lombok详解 深入解析Lombok框架(3)

lombok详解

【步骤四】：使用POST发送请求 GEThttp://localhost:8899/user

[
    {
        "id": 1740047068249387009,
        "name": "zbbmeta",
        "age": 18,
        "sname": null
    },
    {
        "id": 1740047068350050306,
        "name": "springbootIT袋网",
        "age": 20,
        "sname": null
    },
    {
        "id": 1740047068350050307,
        "name": "springbootIT袋网2",
        "age": 22,
        "sname": null
    }
]

4.lombok存在问题

发现uese类的sName属性没有进行赋值

原因

Lombok对于第一个字母小写，第二个字母大写的属性生成的get-set方法和Mybatis以及想法还是说是Java官方认可的get-set方法生成的不一样

lombok生成的User对象

public class User
    implements Serializable
{
    private Long id;
    private String name;
    private Integer age;
    private String sName;
    private static final long serialVersionUID = 1L;
    
    public void setId(Long id) {
        this.id = id; } 
 public void setName(String name) { this.name = name; } 
 public void setAge(Integer age) { this.age = age; } 
 public void setSName(String sName) { this.sName = sName; }
     public Long getId() {
        return this.id;
    } public String getName() {
        return this.name;
    } public Integer getAge() {
        return this.age;
    } public String getSName() {
        return this.sName;
    }

发现sName的set-get方法如下setSName和getSName不是我们想的setsName和getsName

Mybatis（3.4.6版本）解析get-set方法获取属性名字的源码：

/**
 *    Copyright 2009-2019 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.apache.ibatis.reflection.property;
import java.util.Locale;
import org.apache.ibatis.reflection.ReflectionException;
/**
 * @author Clinton Begin
 */
public final class PropertyNamer {
  private PropertyNamer() {
    // Prevent Instantiation of Static Class
  }
  public static String methodToProperty(String name) {
    //is开头的一般是bool类型，直接从第二个(索引)开始截取(简单粗暴)
    if (name.startsWith("is")) {
      name = name.substring(2);
    } else if (name.startsWith("get") || name.startsWith("set")) {//set-get的就从第三个(索引)开始截取
      name = name.substring(3);
    } else {
      throw new ReflectionException("Error parsing property name '" + name + "'.  Didn't start with 'is', 'get' or 'set'.");
    }
 //下面这个判断很重要，解释如下
            //第一句话：name.length()==1
            //       对于属性只有一个字母的，例如private int x;
            //          对应的get-set方法是getX();setX(int x);
            //第二句话：name.length() > 1 && !Character.isUpperCase(name.charAt(1)))
            //属性名字长度大于1，并且第二个(代码中的charAt(1)，这个1是数组下标)字母是小写的
            //      如果第二个char是大写的，那就直接返回name
    if (name.length() == 1 || (name.length() > 1 && !Character.isUpperCase(name.charAt(1)))) {
    //让属性名第一个字母小写，然后加上后面的内容
      name = name.substring(0, 1).toLowerCase(Locale.ENGLISH) + name.substring(1);
    }
    return name;
  }
  public static boolean isProperty(String name) {
    return isGetter(name) || isSetter(name);
  }
  public static boolean isGetter(String name) {
    return (name.startsWith("get") && name.length() > 3) || (name.startsWith("is") && name.length() > 2);
  }
  public static boolean isSetter(String name) {
    return name.startsWith("set") && name.length() > 3;
  }
}