给个代理的题目给大家做做 - 黑马程序员技术交流社区

import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
public class Test {
public static void main(String[] args) throws Exception {
Person p = (Person) Class.forName("Person").newInstance();
HashMap<String, String> m = new HashMap<String, String>();
m.put("username", "itheima");
m.put("password", "it123456");
m.put("birthday", "1998-10-11");
Util.setProperty(p, "username", m.get("username"));
Util.setProperty(p, "password", m.get("password"));
Util.setProperty(p, "birthday", new SimpleDateFormat("yyyy-MM-dd").parse(m.get("birthday")));
System.out.println("username:" + p.getUsername());
System.out.println("password:" + p.getPassword());
System.out.println("birthday:" + p.getBirthday());
}
}
class Util {
public static void setProperty(Object obj, String propertyName, Object value)
throws Exception {
PropertyDescriptor pd = new PropertyDescriptor(propertyName, obj.getClass());
Method methodSet = pd.getWriteMethod();
methodSet.invoke(obj, value);
}
}
class Person {
private String username;
private String password;
private Date birthday;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
}

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import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
public class Test {
public static void main(String[] args) throws Exception {
Class clazz = Class.forName("java.util.Date");
System.out.println("-----------------------------------Properties----------------------------");
Field[] properties = clazz.getDeclaredFields();
for (Field property : properties) {
StringBuilder sb = new StringBuilder(Modifier.toString(property.getModifiers()));
String type = property.getType().toString();
sb.append(" ").append(type).append(" ").append(property.getName());
System.out.println(sb);
}
System.out.println("-------------------------Methods----------------------------------------");
Method[] methods = clazz.getMethods();
for (Method method : methods) {
String name = method.getName();
StringBuilder sb = new StringBuilder(name);
sb.append('(');
Class[] params = method.getParameterTypes();
for (Class param : params) {
sb.append(param.getName());
sb.append(',');
}
if (params != null && params.length != 0)
sb.deleteCharAt(sb.length() - 1);
sb.append(')');
System.out.println(sb);
}
System.out.println("------------------------Constructors-----------------------------------");
Constructor[] constructors = clazz.getConstructors();
for (Constructor constructor : constructors) {
String name = constructor.getName();
StringBuilder sb = new StringBuilder(name);
sb.append('(');
Class[] params = constructor.getParameterTypes();
for (Class param : params) {
sb.append(param.getName());
sb.append(',');
}
if (params != null && params.length != 0)
sb.deleteCharAt(sb.length() - 1);
sb.append(')');
System.out.println(sb);
}
}
}

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import java.util.*;
import java.sql.Date;
import java.lang.reflect.*;
class Person{
String username;
String password;
Date birthday;
public Person(String username,String password,Date birthday){
this.username = username;
this.password = password;
this.birthday = birthday;
}
}
public class P1 {
public static void main(String[] args)
throws Exception{
Map<String,String> map = new TreeMap<String,String>();
map.put("username", "itheima");
map.put("password", "it123456");
map.put("birthday", "1998-10-11");
Person p = Person.class.
getConstructor(new Class[]{String.class,String.class,Date.class}).
newInstance(new Object[]{map.get("username"),map.get("password"),Date.valueOf(map.get("birthday"))});
System.out.println(p.username + "::" + p.password + "::" + p.birthday);//测试之
}
}///:~<span style="line-height: 1.5;">itheima::it123456::1998-10-11</span>

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import java.lang.reflect.*;
import java.util.Date;
public class P2 {
public static void main(String[] args) {
System.out.println("********************Constructor********************");
Constructor[] constructor = Date.class.getDeclaredConstructors();
for(int i=0;i<constructor.length;i++)
System.out.println(constructor[i]);//测试之
System.out.println("********************Method********************");
Method[] method = Date.class.getDeclaredMethods();
for(int i=0;i<method.length;i++)
System.out.println(method[i]);
System.out.println("********************Field********************");
Field[] field = Date.class.getDeclaredFields();
for(int i=0;i<field.length;i++)
System.out.println(field[i]);
}
}

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