Java代码中减少频繁set get

曾经终败给现在 2022-12-25 04:57 191阅读 0赞

## 加入hutool依赖 ##

<dependency>
        <groupId>cn.hutool</groupId>
        <artifactId>hutool-all</artifactId>
        <version>5.5.1</version>
    </dependency>

## 案例 ##

import lombok.Data;
    import lombok.extern.slf4j.Slf4j;
    
    @Slf4j
    @Data
    public class Student_add {
    
        private Integer id;
        private String userName;
        private String sex;
        private String school;
        private String departments;
        private String professional;
        private String phone;
    
        public static void main(String[] args) {
            Student student = new Student();
            student.setId(100);
            student.setUserName("唐");
            student.setSex("男");
            student.setSchool("school");
            student.setDepartments("departments");
            student.setProfessional("professional");
            student.setPhone("13000000000" );
    
            Student_add sStudent_add = new Student_add();
            sStudent_add.setUserName("张");
            sStudent_add.setSex("男");
            sStudent_add.setSchool("school");
            sStudent_add.setDepartments("departments");
            sStudent_add.setProfessional("professional");
            sStudent_add.setPhone("13000000000" );
    
            student.copy(sStudent_add);
    
        }
    
    }

## 控制台 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Rhbmdjdg_size_16_color_FFFFFF_t_70][]

## 实践 ##

import java.io.Serializable;
    import java.util.Date;
    
    import cn.hutool.core.bean.BeanUtil;
    import cn.hutool.core.bean.copier.CopyOptions;
    import com.baomidou.mybatisplus.annotation.IdType;
    import com.baomidou.mybatisplus.annotation.TableId;
    import com.baomidou.mybatisplus.annotation.TableName;
    import lombok.Data;
    import com.fasterxml.jackson.annotation.JsonFormat;
    import org.springframework.format.annotation.DateTimeFormat;
    import org.jeecgframework.poi.excel.annotation.Excel;
    import io.swagger.annotations.ApiModel;
    import io.swagger.annotations.ApiModelProperty;
    import lombok.EqualsAndHashCode;
    import lombok.experimental.Accessors;
    
    /**
     * @Description: 资讯
     * @Date:   2020-11-27
     * @Version: V1.0
     */
    @Data
    @TableName("cc_information")
    @Accessors(chain = true)
    @EqualsAndHashCode(callSuper = false)
    @ApiModel(value="cc_information对象", description="资讯")
    public class CcInformation implements Serializable {
        private static final long serialVersionUID = 1L;
    
    	/**主键*/
    	@TableId(type = IdType.ASSIGN_ID)
        @ApiModelProperty(value = "主键")
        private String id;
    	/**创建人*/
        @ApiModelProperty(value = "创建人")
        private String createBy;
    	/**创建日期*/
    	@JsonFormat(timezone = "GMT+8",pattern = "yyyy-MM-dd HH:mm:ss")
        @DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss")
        @ApiModelProperty(value = "创建日期")
        private Date createTime;
    	/**更新人*/
        @ApiModelProperty(value = "更新人")
        private String updateBy;
    	/**更新日期*/
    	@JsonFormat(timezone = "GMT+8",pattern = "yyyy-MM-dd HH:mm:ss")
        @DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss")
        @ApiModelProperty(value = "更新日期")
        private Date updateTime;
    	/**标题*/
    	@Excel(name = "标题", width = 15)
        @ApiModelProperty(value = "标题")
        private String title;
    	/**所属栏目[数据字典]*/
    	@Excel(name = "所属栏目[数据字典]", width = 15)
        @ApiModelProperty(value = "所属栏目[数据字典]")
        private String beColumn;
    	/**内容*/
    	@Excel(name = "内容", width = 15)
        @ApiModelProperty(value = "内容")
        private String content;
    	/**图片*/
    	@Excel(name = "图片", width = 15)
        @ApiModelProperty(value = "图片")
        private String picture;
    	/**排序*/
    	@Excel(name = "排序", width = 15)
        @ApiModelProperty(value = "排序")
        private Integer sorting;
    	/**状态 1.正常 0.删除*/
    	@Excel(name = "状态 1.正常 0.删除", width = 15)
        @ApiModelProperty(value = "状态 1.正常 0.删除")
        private Integer status;
    
        public void copy(CcInformation source){
            BeanUtil.copyProperties(source,this, CopyOptions.create().setIgnoreNullValue(true));
        }
    }

/**
    	 *  编辑
    	 *
    	 * @param ccInformation
    	 * @return
    	 */
    	@AutoLog(value = "资讯-编辑")
    	@ApiOperation(value="资讯-编辑", notes="资讯-编辑")
    	@PutMapping(value = "/edit")
    	public Result<?> edit(@RequestBody CcInformation ccInformation) {
    		CcInformation findInformation = ccInformationService.getById(ccInformation.getId());
    		if(findInformation == null) {
    			return Result.error("未找到对应数据");
    		}
    		findInformation.copy(ccInformation);
    		findInformation.setUpdateBy(SecurityUtils.getUsername());
    		findInformation.setUpdateTime(new Date());
    		ccInformationService.updateById(ccInformation);
    		return Result.OK("编辑成功!");
    	}

## 说明 ##

适合update方法，当前端需要修改的参数不固定，Student\_add 类里，我们可以都写上，当前端业务发生变化，需要调整修改参数，后端不需要修改代码，只需要前端添加参数

### BeanUtils.copyProperties ###

### Convert.convert ###

实现类转换时会全部复制参数，不适合修改方法，当复制的二个类为同一实体类时

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Rhbmdjdg_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Rhbmdjdg_size_16_color_FFFFFF_t_70 2][]

可以看到，复制前参数也被修改了，Convert只是负责类型转换，当目标类型和原类型一致的时候，会直接返回

# #

## 效率 ##

import cn.hutool.core.bean.BeanUtil;
    import cn.hutool.core.bean.copier.CopyOptions;
    import cn.hutool.core.convert.Convert;
    import lombok.Data;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.BeanUtils;
    
    import java.util.ArrayList;
    import java.util.List;
    
    @Slf4j
    @Data
    public class Student {
    
        private Integer id;
        private String userName;
        private String sex;
        private String school;
        private String departments;
        private String professional;
        private String phone;
    
        public void copy(Student source){
            BeanUtil.copyProperties(source,this, CopyOptions.create().setIgnoreNullValue(true));
        }
        public void copy(Student_add source){
            BeanUtil.copyProperties(source,this, CopyOptions.create().setIgnoreNullValue(true));
        }
    
        public static void main(String[] args){
            Integer number = 50000;
            List<Student> studentList = new ArrayList<>();
            Student copy_student = new Student();
            Student student = new Student();
            student.setUserName("张");
            student.setSex("男");
            student.setSchool("school");
            student.setDepartments("departments");
            student.setProfessional("professional");
            student.setPhone("13000000000" );
            Long startTime = 0L;
            Long endTime = 0L;
            //set
            studentList = new ArrayList<>();
            startTime = System.currentTimeMillis();
            for (int i = 0; i < number; i++) {
                copy_student = new Student();
                copy_student.setId(i);
                copy_student.setUserName(student.getUserName());
                copy_student.setSex(student.getSex());
                copy_student.setSchool(student.getSchool());
                copy_student.setDepartments(student.getDepartments());
                copy_student.setProfessional(student.getProfessional());
                copy_student.setPhone(student.getPhone());
                studentList.add(copy_student);
            }
            endTime = System.currentTimeMillis();
            log.info("set 耗时>>>>>>>>>>>>>>>>>>>: " + (endTime - startTime) + "ms.");
    
            //BeanUtil.copyProperties
            studentList = new ArrayList<>();
            startTime = System.currentTimeMillis();
            for (int i = 0; i < number; i++) {
                copy_student = new Student();
                copy_student.setId(i);
                copy_student.copy(student);
                studentList.add(copy_student);
            }
            endTime = System.currentTimeMillis();
            log.info("BeanUtil.copyProperties 耗时>>>>>>>>>>>>>>>>>>>: " + (endTime - startTime) + "ms.");
    
            //spring
            studentList = new ArrayList<>();
            startTime = System.currentTimeMillis();
            for (int i = 0; i < number; i++) {
                copy_student = new Student();
                copy_student.setId(i);
                BeanUtils.copyProperties(copy_student, student);
                studentList.add(copy_student);
            }
            endTime = System.currentTimeMillis();
            log.info("spring 耗时>>>>>>>>>>>>>>>>>>>: " + (endTime - startTime) + "ms.");
    
            // Convert.convert
            studentList = new ArrayList<>();
            startTime = System.currentTimeMillis();
            for (int i = 0; i < number; i++) {
                copy_student = Convert.convert(Student.class, student);
                copy_student.setId(i);
                studentList.add(copy_student);
            }
            endTime = System.currentTimeMillis();
            log.info("Convert.convert 耗时>>>>>>>>>>>>>>>>>>>: " + (endTime - startTime) + "ms.");
    
        }
    
    }

17:32:28.216 [main] INFO org.jeecg.modules.cc.entity.Student - set 耗时>>>>>>>>>>>>>>>>>>>: 14ms.
    17:32:28.590 [main] INFO org.jeecg.modules.cc.entity.Student - BeanUtil.copyProperties 耗时>>>>>>>>>>>>>>>>>>>: 371ms.
    17:32:28.889 [main] INFO org.jeecg.modules.cc.entity.Student - spring 耗时>>>>>>>>>>>>>>>>>>>: 299ms.
    17:32:28.900 [main] INFO org.jeecg.modules.cc.entity.Student - Convert.convert 耗时>>>>>>>>>>>>>>>>>>>: 11ms.

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