java网络编程和反射基础入门.docx

java反射：获取Class类对象1）getClass()2)通过类名.class3)forName(String className)通过getConstructors（）获取类对应的构造方法返回值是Constructor1 客户端Client.javapackage com.chinasofti.eec.demo;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import .ServerSocket;import .Socket;import .UnknownHostException;import java.util.Scanner;public class Client private static PrintWriter pw = null;/打印private static BufferedReader br = null;/缓冲流private static Socket s;private static ServerSocket ss;private static Scanner scan = new Scanner(System.in);public static void main(String args) try s = new Socket(,5500);pw = new PrintWriter(new OutputStreamWriter(s.getOutputStream();br = new BufferedReader(new InputStreamReader(s.getInputStream();while(true)System.out.println(客户端说：);String str = scan.nextLine();pw.println(str);pw.flush();String string = br.readLine();System.out.println(服务端说：+string);if(byby.equals(str)break; catch (UnknownHostException e) / TODO Auto-generated catch blocke.printStackTrace(); catch (IOException e) / TODO Auto-generated catch blocke.printStackTrace();try br.close();pw.close(); catch (IOException e) / TODO Auto-generated catch blocke.printStackTrace();Person.javapackage com.chinasofti.eec.demo;public class Person public String name=zhansgan;public int age=18;public Person(String name, int age) super(); = name;this.age = age;public String getName() return name;public void setName(String name) = name;public int getAge() return age;public void setAge(int age) this.age = age;Overridepublic String toString() return Person name= + name + , age= + age + ;2 服务器Service.javapackage com.chinasofti.eec.demo;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import .ServerSocket;import .Socket;import java.util.Scanner;/* * 服务端 * author Administrator * */public class Service private static PrintWriter pw = null;/打印private static BufferedReader br = null;/缓冲流private static Socket s;private static ServerSocket ss;private static Scanner scan = new Scanner(System.in);public static void main(String args) try ss = new ServerSocket(5500);System.out.println(服务器启动成功-);s = ss.accept();/等待客户端链接System.out.println(链接成功+s.getRemoteSocketAddress();/返回此套接字链接端口的地址br = new BufferedReader(new InputStreamReader(s.getInputStream();/准备读取客户端发过来的信息pw = new PrintWriter(new OutputStreamWriter(s.getOutputStream();/准备向客户端写入信息while(true)String string = br.readLine();/读取客户端发过来的信息System.out.println(服务端接受到：+string);System.out.println(服务端说：);String str = scan.next();pw.println(str);/把服务端想说的话发送给客户端pw.flush();if(byby.equals(str)break; catch (IOException e) / TODO Auto-generated catch blocke.printStackTrace();try br.close();pw.close(); catch (IOException e) / TODO Auto-generated catch blocke.printStackTrace();3 获取class对象package com.chinasofti.eec.demo;public class ClassDemo public static void main(String args) String str = helloWorld;Class c = str.getClass();/获取Class类对象System.out.println(c.getName();ClassDemo1.javapackage com.chinasofti.eec.classdemo;public class ClassDemo public static void main(String args) A a = new A();Class c = a.getClass();String name = c.getName();System.out.println(name);class A4 通配符package com.chinasofti.eec.demo;public class ClassDemo2 public static void main(String args) Class cls = String.class;System.out.println(cls.getName();ClassDemo2.javapackage com.chinasofti.eec.classdemo;import com.chinasofti.eec.vo.Person;/* * 三种方法得到Class类对象的方法 * author Administrator * */public class ClassDemo2 public static void main(String args) Class c1 = null;Class c2 = null;Class c3 = null;/第一种方式（最常用的一种）try c1 = Class.forName(com.chinasofti.eec.vo.Person); catch (ClassNotFoundException e) / TODO Auto-generated catch blocke.printStackTrace();c2 = new Person().getClass();c3 = Person.class;String name1 = c1.getName();String name2 = c2.getName();String name3 = c3.getName();System.out.println(name1+ +name2+ +name3);ClassDemo.javapackage com.chinasofti.eec.demo;public class ClassDemo3 public static void main(String args) throws ClassNotFoundException Class cls = Class.forName(java.io.File);System.out.println(cls.getName();5 反射获得类的构造器package com.chinasofti.eec.demo;public class ClassDemo4 public static void main(String args) throws ClassNotFoundException, InstantiationException, IllegalAccessException Class cls = Class.forName(com.chinasofti.eec.demo.Person);Person per = (Person)cls.newInstance();per.setName(123);per.setAge(18);System.out.println(per);ClassDemo3.javapackage com.chinasofti.eec.classdemo;import java.lang.reflect.Constructor;import java.lang.reflect.InvocationTargetException;import com.chinasofti.eec.vo.Person;/* * 通过反射获得类的构造器并初始化参数 * author Administrator * */public class ClassDemo3 public static void main(String args) Class c = null;Constructor con = null;try c = Class.forName(com.chinasofti.eec.vo.Person); catch (ClassNotFoundException e) / TODO Auto-generated catch blocke.printStackTrace();con = c.getConstructors();Person person = null;try person = (Person)con1.newInstance(123,10); catch (Exception e) / TODO Auto-generated catch blocke.printStackTrace();System.out.println(person);6 获取构造对象package com.chinasofti.eec.demo;import java.lang.reflect.Constructor;import java.lang.reflect.InvocationTargetException;public class ClassDemo5 public static void main(String args) throws NoSuchMethodException, SecurityException, ClassNotFoundException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException Class cls = Class.forName(com.chinasofti.eec.demo.Person);Constructor con = cls.getConstructors();/获取到构造方法Person per = (Person)con0.newInstance(gqk,18);System.out.println(per);ClassDemo5.javapackage com.chinasofti.eec.classdemo;/* * 获取全部的构造方法 */import java.lang.reflect.Constructor;public class ClassDemo4 public static void main(String args) Class c = null;Constructor con = null;try c = Class.forName(com.chinasofti.eec.vo.Person); catch (ClassNotFoundException e) e.printStackTrace();con = c.getConstructors();for (int i = 0; i con.length; i+) System.out.println(coni);7 方法类package com.chinasofti.eec.demo;import java.lang.reflect.Method;public class ClassDemo6 public static void main(String args) throws ClassNotFoundException, InstantiationException, IllegalAccessException Class cls = Class.forName(com.chinasofti.eec.demo.Person);Method m = cls.getMethods();for (int i = 0; i m.length; i+) System.out.println(mi.getParameterTypes()+ +mi);ClassDemo6.javapackage com.chinasofti.eec.classdemo;/* * 获取构造方法里面的信息 */import java.lang.reflect.Constructor;import java.lang.reflect.Modifier;public class ClassDemo5 public static void main(String args) Class c = null;Constructor con = null;try c = Class.forName(com.chinasofti.eec.vo.Person); catch (ClassNotFoundException e) / TODO Auto-generated catch blocke.printStackTrace();con = c.getConstructors();for (int i = 0; i con.length; i+) /获得构造方法中的全部参数Class c1 = coni.getParameterTypes();/获得修饰符int num = coni.getModifiers();String xiushi = Modifier.toString(num);System.out.println(xiushi);/输出修饰符System.out.println(coni.getName();System.out.println();for (int j = 0; j c1.length; j+) System.out.println(c1j.getName();System.out.println();8 invoke反射package com.chinasofti.eec.demo;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;public class ClassDemo7 public static void main(String args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, NoSuchMethodException, SecurityException Class cls = null;cls = Class.forName(com.chinasofti.eec.demo.Person);Method m = cls.getMethod(getName);Person person = new Person(zhangsan,18);String person1 = null;try person1 = (String)m.invoke(person); catch (IllegalArgumentException | InvocationTargetException e) / TODO Auto-generated catch blocke.printStackTrace();System.out.println(person1);ClassDemo7.javapackage com.chinasofti.eec.classdemo;import java.lang.reflect.Constructor;import java.lang.reflect.InvocationTargetException;import com.chinasofti.eec.vo.Person;/* * 通过反射来创建Person类的对象 * author Administrator * */public class ClassDemo6 public static void main(String args) Class c = null;try c = Class.forName(com.chinasofti.eec.vo.Person); catch (ClassNotFoundException e) / TODO Auto-generated catch blocke.printStackTrace();Person person = null;try person = (Person)c.newInstance();person.setName(123);person.setAge(18); catch (InstantiationException e) / TODO Auto-generated catch blocke.printStackTrace(); catch (IllegalAccessException e) / TODO Auto-generated catch blocke.printStackTrace();System.out.println(person);ClassDemo8.javapackage com.chinasofti.eec.classdemo;import java.lang.reflect.Method;public class InvokeDemo public static void main(String args) Class c = null;Object obj = null;try c = Class.forName(com.chinasofti.eec.vo.Person);obj = c.newInstance(); catch (Exception e) / TODO Auto-generated catch blocke.printStackTrace();setters(obj,name,霍建华,String.class);setters(obj,age,30,int.class);System.out.println(姓名是：+getters(obj, name)+ 年龄是：+getters(obj, age);/* * 设定4个参数 * Object obj : 要操作的对象 * String att : 要操作的属性 * Object value: 属性设置的值 * Class type : 属性的类型 */public static void setters (Object obj,String att,Object value,Class type)try Method m = obj.getClass().getMethod(set+changeFirst(att), type);m.invoke(obj, value); catch (Exception e) / TODO Auto-generated catch blocke.printStackTrace(); public static Object getters (Object obj,String att)Object o = null;try Method m = obj.getClass().getMethod(get+changeFirst(att);o = m.invoke(obj); catch (Exception e) / TODO Auto-generated catch blocke.printStackTrace();return o; public static String changeFirst(String att)String str =att.substring(0, 1).toUpperCase()+att.substring(1);return str;反射package com.chinasofti.eec.classdemo;import java.lang.reflect.Field;import com.chinasofti.eec.vo.Person;public class Ref public static void main(String args) throws IllegalArgumentException, IllegalAccessException Class c = null;Field field = null;try c = Class.forName(com.chinasofti.eec.vo.Person); catch (ClassNotFoundException e) / TODO Auto-generated catch blocke.printStackTrace();try field = c.getDeclaredField(age); catch (Exception e) / TODO Auto-generated catch blocke.printStackTrace();Person obj = new Person(郭桥坤,28);/field.set(obj, 13123);int str = (int)field.get(obj);System.out.println(str);9 底层get set方法package com.chinasofti.eec.demo;import java.lang.reflect.InvocationTargetExceptio