Java反射调用ashx

news2024/11/15 15:56:08

这篇文章卡了大概一周，一个是没时间，只能带娃加锻炼间隙挤点时间，一个是碰到了问题卡住了。本篇实现反射调用ashx实现类的基础结构。

首先申明ashx的接口，所有的ashx实现类继承实现该接口的基类

package appcode;
import java.io.*;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
//http执行请求接口
public interface IBaseHttpHandler {
    /// <summary>
    /// 执行请求
    /// </summary>
    /// <param name="request">请求对象</param>
    /// <param name="response">响应对象</param>
    public void ProcessRequest(HttpServletRequest request, HttpServletResponse response);
}

然后实现第一个不需要会话的基类

package appcode;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.PrintWriter;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.lang.Class;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.jar.JarFile;
import java.util.jar.JarEntry;
import LIS.Core.MultiPlatform.LISContext;
import appcode.IBaseHttpHandler;
//实现不带会话的请求基类
public class BaseHttpHandlerNoSession implements IBaseHttpHandler {
    ///请求对象
    public HttpServletRequest Request=null;

    ///响应对象
    HttpServletResponse Response=null;


    ///输出数据到前台
    private void Write(PrintWriter writer,String str)
    {
        writer.println(str);
        writer.flush();
        writer.close();
    }


    /// <summary>
    /// 执行请求
    /// </summary>
    /// <param name="request">请求对象</param>
    /// <param name="response">响应对象</param>
    public void ProcessRequest(HttpServletRequest request, HttpServletResponse response)
    {
        try {
            Request = request;
            Response = response;
            //前台传入的要调用的方法
            String method = LISContext.GetRequest(request, "Method");
            if (method != "") {
                //得到方法
                Method m = this.getClass().getMethod(method);
                if (m != null) {
                    //执行
                    Object ret = m.invoke(this);
                    PrintWriter writer = response.getWriter();
                    if (ret == null) {
                        Write(writer, "");
                    } else {
                        Write(writer, (String) ret);
                    }
                } else {
                    //没有指定名称的方法
                }
            } else {
                //没按要求传调用方法
            }
        }
        catch (Exception ex)
        {
            ex.printStackTrace();
        }
    }
}

然后实现主中间件中转调用实现的ashx

import appcode.IBaseHttpHandler;

import java.io.*;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.concurrent.ConcurrentHashMap;
import java.net.URL;
import java.net.URLClassLoader;

import java.util.*;


@javax.servlet.annotation.WebServlet(name = "MianMiddleware")
public class MianMiddleware extends javax.servlet.http.HttpServlet {

    /// <summary>
    /// 缓存路径和类型，允许多线程读一个线程写
    /// </summary>
    private static ConcurrentHashMap<String, Class> hsType = new ConcurrentHashMap<>();

    ///执行post请求
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html");
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
        String url=request.getRequestURI();
        //解析得到类名
        String className = url.split("\\.")[0];
        PrintWriter writer = response.getWriter();
        //反射得到类型
        Object objDeal = GetObjectByConfString(className,writer);
        //转换处理接口
        if(objDeal!=null)
        {
            //转换成接口
            appcode.IBaseHttpHandler baseDeal=(appcode.IBaseHttpHandler)objDeal;
            baseDeal.ProcessRequest(request,response);
        }
        else
        {
            Write(writer,"为找到名称为:"+className+"的处理类");
        }
    }

    /// <summary>
    /// 通过配置得当对象
    /// </summary>
    /// <param name="confStr">配置/UI/sys/ashx/ashCommonNoSession</param>
    /// <returns></returns>
    public static Object GetObjectByConfString(String confStr,PrintWriter writer) {
        try {
            //取第一部分
            if (confStr.charAt(0) == '/') {
                confStr = confStr.substring(1);
            }
            if (!hsType.containsKey(confStr)) {
                URL urlBase = new File("D:\\Java业余\\jbase\\Lib\\appcode.jar").toURI().toURL();
                //自己生成jar包路径
                URL url = new File("D:\\Java业余\\jbase\\Lib\\AshDemo.jar").toURI().toURL();
                URL[] urls = new URL[]{urlBase,url};
                //加载程序集，这里很重要，一定要指定父加载器，否则加载的类和父加载器的类不认为是一个类
                URLClassLoader loader = new URLClassLoader(urls, MianMiddleware.class.getClassLoader());
                ClassLoader  loader1=Thread.currentThread().getContextClassLoader();
                //加载类
                Class c = loader.loadClass("AshDemo.ashDemo");
                //先写死，后面执行编译和从jar包反射
                hsType.put(confStr, c);
            }
            Class c = hsType.get(confStr);
            //创建对象
            Object o = c.newInstance();
            return o;
        }
        catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }

    //get直接走post的逻辑
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request,response);
    }

    ///输出数据到前台
    private static void Write(PrintWriter writer,String str)
    {
        writer.println(str);
        writer.flush();
        writer.close();
    }

}