return "Person [id=" + id + ", name=" + name + ", age=" + age + "]";
}
public Person(int id, String name, int age) {
super();
this.id = id;
this.name = name;
this.age = age;
}
public Person() {
super();
}
}
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用于实现添加删除更新功能的接口
public interface Service {
void addNew(Person person);
void delete(Integer id);
void update(Person person);
}
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实现接口的业务类
public class ServiceImp implements Service {
private Map<Integer, Person> map= new HashMap<Integer,Person>();
public ServiceImp(){//空异常
map.put(1001, new Person(1002,"tom1", 15));
map.put(1002, new Person(1002,"tom1", 15));
map.put(1003, new Person(1002,"tom1", 15));
}
public Map<Integer, Person> getMap() {
return map;
}
public void setMap(Map<Integer, Person> map) {
this.map = map;
}
@Override
public void addNew(Person person) {
// TODO Auto-generated method stub
map.put(person.getId(), person);
}
@Override
public void delete(Integer id) {
// TODO Auto-generated method stub
map.remove(id);
}
@Override
public void update(Person person) {
// TODO Auto-generated method stub
map.put(person.getId(), person);
}
}
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测试类
public static void main(String[] args) {
// TODO Auto-generated method stub
Service target=new ServiceImp();//直接报空异常
}
}
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在测试类中一new对象就在业务类中报空异常
Exception in thread "main" java.lang.NullPointerException
at com.sun.proxy.ServiceImp.<init>(ServiceImp.java:10)
at com.sun.proxy.TestProxy.main(TestProxy.java:11)
求助高手 实在不知道怎么回事