用Java反射输出对象的所有属性的值

获取对象的类类型

Class cls = obj.getClass();

用类类型获取属性数组

Field[] fields = cls.getDeclaredFields();

遍历属性数组，将属性设置为外部可见,然后输出

for (Field field:fields) {
field.setAccessible(true);
try {
System.out.println(field.getName()+":"+field.get(obj));
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}

完整代码：

import java.lang.reflect.Field;

public class PrintAllFields {
public static void printAllFields(Object obj){
Class    cls=obj.getClass();
Field[] fields=cls.getDeclaredFields();
System.out.println("共有"+fields.length+"个属性");
for (Field field:fields) {
field.setAccessible(true);
try {
System.out.println(field.getName()+":"+field.get(obj));
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}

public static void main(String[] args) {
Student student=new Student();
student.setId(2014222);
student.setName("李利");
student.setAge(22);
student.setSex(1);
student.setGrade(3);
PrintAllFields.printAllFields(student);
}
}

public class Student {
private int id;
private String name;
private int age;
private int grade;
private int sex;

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

public int getGrade() {
return grade;
}

public void setGrade(int grade) {
this.grade = grade;
}

public int getSex() {
return sex;
}

public void setSex(int sex) {
this.sex = sex;
}
}