Apache.Tomcat 调用Servlet原理之Class类的反射机制，用orc类解

有一个兽人类

package com.swift.servlet;public class OrcDemo {private int hp;private int mp;private int atk;public int getHp() {return hp;}public void setHp(int hp) {this.hp = hp;}public int getMp() {return mp;}public void setMp(int mp) {this.mp = mp;}public int getAtk() {return atk;}public void setAtk(int atk) {this.atk = atk;}public OrcDemo() {}public OrcDemo(int hp, int mp, int atk) {super();this.hp = hp;this.mp = mp;this.atk = atk;}public void orcInfo() {System.out.println("hp"+hp+"mp"+mp+"atk"+atk);}public static void main(String[] args) {OrcDemo orc=new OrcDemo(3000,2000,500);orc.orcInfo();}}

原本的兽人对象使用方法：public static void main(String[] args) {OrcDemo orc=new OrcDemo(3000,2000,500);orc.orcInfo();}使用Class类反射，得到兽人对象全部内容：

Class c=Class.forName(“OrcDemo”);OrcDemo od=(OrcDemo)c.newInstance();od.orcInfo();

apache.tomcat就是使用这种方法调用的Servlet

web.xml配置文件中<servlet>　　　　<servlet-name>ServletDemo</servlet-name>　　　　<servlet-class>com.swift.servlet.TestServlet</servlet-class></servlet><servlet-mapping>　　　　<servlet-name>ServletDemo<servlet-name>　　　　<url-pattern>/test</url-pattern></servlet-mapping>

把上面的<servlet-class>com.swift.servlet.TestServlet</servlet-class>中的com.swift.servlet.TestServlet拿出来使用即可

应用到刚才写的反射代码Class c=Class.forName("OrcDemo");OrcDemo od=(OrcDemo)c.newInstance();od.orcInfo();变为

Class c=Class.forName("com.swift.servlet.TestServlet");//ServletDemo sd=(ServletDemo)c.newInstance();/*tomcat就是因为不知道有      ServletDemo这个类，才使用反射方法，这里我们可以用他的父类，多态就可以了*/HttpServlet hs=c.newInstance();hs.doGet();

前有阻碍，奋力把它冲开，运用炙热的激情，