Java对象间属性值的复制-Spring的BeanUtil

电玩女神 2022-06-09 06:28 182阅读 0赞

需求：两个对象中有相同类型相同名称的属性，把一个对象中的属性值复制到另一个对象。

先把spring那5个核心的jar包导入到项目中  
spring-core-3.2.0.RELEASE.jar  
spring-beans-3.2.0.RELEASE.jar  
spring-context-3.2.0.RELEASE.jar  
spring-expression-3.2.0.RELEASE.jar

新建一个Person类

public class Person {
        private Double avgScore;
        private String courseName;
        private int num;
        private Date createTime;
    
    
        public Double getAvgScore() {
            return avgScore;
        }
        public void setAvgScore(Double avgScore) {
            this.avgScore = avgScore;
        }
        public String getCourseName() {
            return courseName;
        }
        public void setCourseName(String courseName) {
            this.courseName = courseName;
        }
        public int getNum() {
            return num;
        }
        public void setNum(int num) {
            this.num = num;
        }
        public Date getCreateTime() {
            return createTime;
        }
        public void setCreateTime(Date createTime) {
            this.createTime = createTime;
        }
    
        @Override
        public String toString() {
            return "Person [avgScore=" + avgScore + ", courseName=" + courseName
                    + ", num=" + num + ", createTime=" + createTime + "]";
        }
    
    }

新建一个Student类

public class Student extends Person{ 
        private String studentName;
    
        public String getStudentName() {
            return studentName;
        }
    
        public void setStudentName(String studentName) {
            this.studentName = studentName;
        }
    
    
        @Override
        public String toString() {
            return "Student [studentName=" + studentName + ", getAvgScore()="
                    + getAvgScore() + ", getCourseName()=" + getCourseName()
                    + ", getNum()=" + getNum() + ", getCreateTime()="
                    + getCreateTime() + ", toString()=" + super.toString()
                    + ", getClass()=" + getClass() + ", hashCode()=" + hashCode()
                    + "]";
        }
    
    
    }

编写一个测试类

public class Test {
    
        @Test
        public void test(){
            Person p=new Person();
            p.setAvgScore(3.0);
            p.setCourseName("courseName");
            p.setCreateTime(new Date());
            p.setNum(2);
    
            Student s=new Student();
            s.setStudentName("studentName");
            BeanUtils.copyProperties(p, s);
    
            System.out.println(p);
            System.out.println("-------------------");
            System.out.println(s);
        }
    
    
    }

运行结果为

Person [avgScore=3.0, courseName=courseName, num=2, createTime=Wed Aug 30 08:41:56 CST 2017]
    -------------------
    Student [studentName=studentName, getAvgScore()=3.0, getCourseName()=courseName, getNum()=2, getCreateTime()=Wed Aug 30 08:41:56 CST 2017, toString()=Person [avgScore=3.0, courseName=courseName, num=2, createTime=Wed Aug 30 08:41:56 CST 2017], getClass()=class cn.eaglezsx.test.Student, hashCode()=5784348]

可以看到Person对象中的属性值复制到了Student中

需求：将一个list中对象的属性值复制到另一个list中

@Test
        public void t2(){
    
            List<Person> pL=new ArrayList<>();
    
            Person p=new Person();
            p.setAvgScore(3.0);
            p.setCourseName("courseName");
            p.setCreateTime(new Date());
            p.setNum(2);
    
            Person p2=new Person();
            p2.setAvgScore(4.0);
    
            pL.add(p);
            pL.add(p2);
    
            List<Student> sL=new ArrayList<>();
    
            for(Person person:pL){
                Student student=new Student();
                BeanUtils.copyProperties(person, student);
                sL.add(student);
            }
    
    
            System.out.println(pL);
            System.out.println("-----------------------");
            System.out.println(sL);
    
        }

运行结果为

[Person [avgScore=3.0, courseName=courseName, num=2, createTime=Wed Aug 30 08:48:49 CST 2017], Person [avgScore=4.0, courseName=null, num=0, createTime=null]]
    -----------------------
    [Student [studentName=null, getAvgScore()=3.0, getCourseName()=courseName, getNum()=2, getCreateTime()=Wed Aug 30 08:48:49 CST 2017, toString()=Person [avgScore=3.0, courseName=courseName, num=2, createTime=Wed Aug 30 08:48:49 CST 2017], getClass()=class cn.eaglezsx.test.Student, hashCode()=32846040], Student [studentName=null, getAvgScore()=4.0, getCourseName()=null, getNum()=0, getCreateTime()=null, toString()=Person [avgScore=4.0, courseName=null, num=0, createTime=null], getClass()=class cn.eaglezsx.test.Student, hashCode()=5890565]]

可以看到pL总对象的值复制到了sL中了。