内省是反射的一种特例

由于在框架底层中要频繁地操作javabean,而利用反射操作比较麻烦。所以为了方便操作javabean，sun公司开发出一套API提高效率

 

Java内省机制是针对JavaBean进行操作的

 

public class Person {        private String name;    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;    }    private int age; }

 

 

 

 

public class TestIntrospector {     @Test    public void tes1() throws Exception {        Class
      cl = Class.forName("com.irish.aop.cc.Person");        //在bean上进行内省        BeanInfo beaninfo = Introspector.getBeanInfo(cl, Object.class);        PropertyDescriptor[] pro = beaninfo.getPropertyDescriptors();        Person p = new Person();        System.out.print("Person的属性有:");        for (PropertyDescriptor pr : pro) {            System.out.print(pr.getName() + " ");        }        System.out.println("");        for (PropertyDescriptor pr : pro) {            Method writeme = pr.getWriteMethod();            if (pr.getName().equals("name")) {                writeme.invoke(p, "xiong");            }            if (pr.getName().equals("age")) {                writeme.invoke(p, 23);            }            Method method = pr.getReadMethod();            System.out.print(method.invoke(p) + " ");         }    }     @Test    public void test2() throws Exception {        PropertyDescriptor pro = new PropertyDescriptor("name", Person.class);        Person preson=new Person();        Method  method=pro.getWriteMethod();        method.invoke(preson, "xiong");        System.out.println(pro.getReadMethod().invoke(preson));    }}

 

 

 

怎么让后台的Model对象统一的接收表单提交过来的参数

Servlet

public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        request.setCharacterEncoding("UTF-8");        user u=new user();        populate(request.getParameterMap(),u);        System.out.println(u);            }        private void populate(Map
     
       map,user u){        try {            Map
      
        params=map;            //1 获得 java Bean的描述信息            BeanInfo info =Introspector.getBeanInfo(user.class);            //2 获得 User中的属性信息            PropertyDescriptor [] pds =info.getPropertyDescriptors();            //3 遍历属性信息            for (PropertyDescriptor pd : pds) {                String[] param=params.get(pd.getName());                if (param!=null && param.length>0) {                    pd.getWriteMethod().invoke(u, param[0]);                }            }        } catch (Exception e) {            e.printStackTrace();        }    }
      
     

 

JavaBean

public class user {    private String name;    private String password;    public user(){                super();    }        public String getName() {        return name;    }     public void setName(String name) {        this.name = name;    }     public String getPassword() {        return password;    }     public void setPassword(String password) {        this.password = password;    }        @Override    public String toString() {        return "user [name=" + name + ", password=" + password + " ]";    }}

Jsp

        
     
                  用户名:
      
      
            密码: