为什么无法打印POJO里面的属性?

我写了一个工具类,当我输入一个对象,直接打印对象里面的属性

public class JavaUtil {
    public static void toString(Object object){
        Class clazz = object.getClass();//获得类对象
        StringBuilder sb = new StringBuilder();
        sb.append("成员变量:\n");
        Field[] fields = clazz.getFields();
        for (Field field:fields){
            sb.append(field.toGenericString()+"\n");
        }
        System.out.println(sb.toString());
    }
}
 public class POJO {
    private Integer id;
    private String name;
    public POJO() {
    }
    public POJO(Integer id,  String name) {
        this.setId(id);
        this.setName(name);
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}
 public class Test {
    public static void main(String[] args) {
        POJO pojo = new POJO();
        pojo.setId(1);
        pojo.setName("任冠宇");
        JavaUtil.toString(pojo);
    }
}