Java反射小案例

墨蓝 2022-04-12 09:10 280阅读 0赞

#### Java反射小案例(一) ####

**如题：一个实体类，实例化两个对象A和B，将A对象属性赋值。 通过反射的技术将A对象的属性值赋给B对象（同一个类，不同对象相同属性赋值）**

// 实例化两个对象A和B
    		Student stuA=new Student(1,"赵柳","女","18","湖北武汉","2018-12-1");
    		Student stuB=new Student();
    		
    // 获取Student B类对象
    		Class clazz = stuB.getClass();
    		
    // 获取Student类 所有属性
    		Field[] declaredFields = clazz.getDeclaredFields();
    		for (Field field : declaredFields) { 
    // 打破封装(私有属性)
    			field.setAccessible(true);
    // 使用set方法赋值，参数一：需赋值的对象，参数二：获取值的对象
    			field.set(stuB, field.get(stuA));
    		}
    		System.out.println(stuB);
    	}

Student类

package com.simple.regflectOne;
    
    public class Student { 
    	private int studentId;
    	private String studentName;
    	private String studentGender;
    	private String studentAge;
    	private String adress;
    	private String birthDay;
    
    	public int getStudentId() { 
    		return studentId;
    	}
    
    	public void setStudentId(int studentId) { 
    		this.studentId = studentId;
    	}
    
    	public String getStudentName() { 
    		return studentName;
    	}
    
    	public void setStudentName(String studentName) { 
    		this.studentName = studentName;
    	}
    
    	public String getStudentGender() { 
    		return studentGender;
    	}
    
    	public void setStudentGender(String studentGender) { 
    		this.studentGender = studentGender;
    	}
    
    	public String getStudentAge() { 
    		return studentAge;
    	}
    
    	public void setStudentAge(String studentAge) { 
    		this.studentAge = studentAge;
    	}
    
    	public String getAdress() { 
    		return adress;
    	}
    
    	public void setAdress(String adress) { 
    		this.adress = adress;
    	}
    
    	public String getBirthDay() { 
    		return birthDay;
    	}
    
    	public void setBirthDay(String birthDay) { 
    		this.birthDay = birthDay;
    	}
    
    	public Student(int studentId, String studentName, String studentGender,
    			String studentAge, String adress, String birthDay) { 
    		super();
    		this.studentId = studentId;
    		this.studentName = studentName;
    		this.studentGender = studentGender;
    		this.studentAge = studentAge;
    		this.adress = adress;
    		this.birthDay = birthDay;
    	}
    
    	public Student() { 
    		super();
    	}
    
    	@Override
    	public String toString() { 
    		return "Student [studentId=" + studentId + ", studentName="
    				+ studentName + ", studentGender=" + studentGender
    				+ ", studentAge=" + studentAge + ", adress=" + adress
    				+ ", birthDay=" + birthDay + "]";
    	}
    
    }

#### Java反射小案例(二) ####

**如题： 两个不同实体类，实例化两个对象A和B，将A对象属性赋值。 通过反射的技术将A对象的属性值赋给B对象中相同的属性（不同类，相同属性赋值）**

package RegflectOne;
    
    import java.lang.reflect.Field;
    
    public class TestTwo { 
    
    	public static void main(String[] args) throws IllegalArgumentException,
    			IllegalAccessException { 
    		// 实例化两个对象A和B
    		Student stuA = new Student(1, "王武", "男", "18", "湖北武汉", "2018-12-1");
    		Teacher teaB = new Teacher();
    
    		// 获取类对象
    		Class stu = Student.class;
    		Class tea = Teacher.class;
    
    		// 获取类类中属性
    		Field[] declaredFieldsStu = stu.getDeclaredFields();
    		Field[] declaredFieldsTea = tea.getDeclaredFields();
    
    		for (Field fieldStu : declaredFieldsStu) { 
    			for (Field fieldTea : declaredFieldsTea) { 
    				// 打破封装
    				fieldStu.setAccessible(true);
    				fieldTea.setAccessible(true);
    				//判断给相同的属性赋值
    				if (fieldStu.getName().equals(fieldTea.getName())) { 
    					fieldTea.set(teaB, fieldStu.get(stuA));
    				}
    			}
    		}
    		 System.out.println(teaB);
    	}
    }

Student类

package RegflectOne;
    
    public class Student { 
    	private int studentId;
    	private String studentName;
    	private String studentGender;
    	private String studentAge;
    	private String adress;
    	private String birthDay;
    
    	public int getStudentId() { 
    		return studentId;
    	}
    
    	public void setStudentId(int studentId) { 
    		this.studentId = studentId;
    	}
    
    	public String getStudentName() { 
    		return studentName;
    	}
    
    	public void setStudentName(String studentName) { 
    		this.studentName = studentName;
    	}
    
    	public String getStudentGender() { 
    		return studentGender;
    	}
    
    	public void setStudentGender(String studentGender) { 
    		this.studentGender = studentGender;
    	}
    
    	public String getStudentAge() { 
    		return studentAge;
    	}
    
    	public void setStudentAge(String studentAge) { 
    		this.studentAge = studentAge;
    	}
    
    	public String getAdress() { 
    		return adress;
    	}
    
    	public void setAdress(String adress) { 
    		this.adress = adress;
    	}
    
    	public String getBirthDay() { 
    		return birthDay;
    	}
    
    	public void setBirthDay(String birthDay) { 
    		this.birthDay = birthDay;
    	}
    
    	public Student(int studentId, String studentName, String studentGender,
    			String studentAge, String adress, String birthDay) { 
    		super();
    		this.studentId = studentId;
    		this.studentName = studentName;
    		this.studentGender = studentGender;
    		this.studentAge = studentAge;
    		this.adress = adress;
    		this.birthDay = birthDay;
    	}
    
    	public Student() { 
    		super();
    	}
    
    	@Override
    	public String toString() { 
    		return "Student [studentId=" + studentId + ", studentName="
    				+ studentName + ", studentGender=" + studentGender
    				+ ", studentAge=" + studentAge + ", adress=" + adress
    				+ ", birthDay=" + birthDay + "]";
    	}
    
    }

Teacher类

package RegflectOne;
    
    public class Teacher { 
    	private int teacherId;
    	public String studentName;
    	public String studentGender;
    	
    	public int getTeacherId() { 
    		return teacherId;
    	}
    
    	public void setTeacherId(int teacherId) { 
    		this.teacherId = teacherId;
    	}
    
    	public String getStudentName() { 
    		return studentName;
    	}
    
    	public void setStudentName(String studentName) { 
    		this.studentName = studentName;
    	}
    
    	public String getStudentGender() { 
    		return studentGender;
    	}
    
    	public void setStudentGender(String studentGender) { 
    		this.studentGender = studentGender;
    	}
    
    	public Teacher(int teacherId, String studentName, String studentGender) { 
    		super();
    		this.teacherId = teacherId;
    		this.studentName = studentName;
    		this.studentGender = studentGender;
    	}
    
    	public Teacher() { 
    		super();
    	}
    
    	@Override
    	public String toString() { 
    		return "Teacher [teacherId=" + teacherId + ", studentName="
    				+ studentName + ", studentGender=" + studentGender + "]";
    	}
    	
    	
    }