同一服务器中两个 Web 应用程序之间的通信

java tomcat servlets tomcat6 cross-context

2022-09-03 14:11:00

都

我有2个Web应用程序，Web1和Web2，部署在我的tomcat服务器上。我希望 Web1 中的类调用 Web2 中类上的方法。一种方法是使用Web服务。有没有其他方法类似于在同一Web应用程序上的类上调用方法？

谢谢。

答案 1

是的。这是可能的。它尝试使用getServletContext（）.getContext（）方法使用相同的servlet容器。

首先，您需要在下面的文件中进行更改

（视窗）C：\Program Files\Apache Software Foundation\Tomcat 7.0\conf\context.xml 将 crossContext 的值设置为 true。

上下文.xml

<Context crossContext="true">

    <!-- Default set of monitored resources -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->

    <!-- Uncomment this to enable Comet connection tacking (provides events
         on session expiration as well as webapp lifecycle) -->
    <!--
    <Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
    -->

</Context>

请注意，crossContext=“true”。

假设您有两个名为 InterServletComm1 和 InterServletComm2 的 Web 应用程序，每个 Web 应用程序中分别具有 Servlet Servlet1 和 Servlet1。然后，每个 servlet 中的代码如下所示：

Servlet1.java

package interServletComm1;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlet1
 */
@WebServlet("/Servlet1")
public class Servlet1 extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public Servlet1() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
    {
        response.setContentType("text/html");
        PrintWriter pw = response.getWriter();

        request.setAttribute("name", "WebApp1");
        ServletContext context = getServletContext().getContext("/InterServletComm2");
        RequestDispatcher rd = context.getRequestDispatcher("/Servlet2");
        rd.forward(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}

Servlet2.java

package interServletComm2;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlet2
 */
@WebServlet("/Servlet2")
public class Servlet2 extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public Servlet2() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
    {
        response.setContentType("text/html");
        PrintWriter pw = response.getWriter();
        String name = (String) request.getAttribute("name");
        pw.println("This is web application 2.");
        pw.println("<br>The value received from web application one is: " + name);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}

上面的代码从InterServletComm1发送属性名称，并在InterServletComm2中接收。如果这个答案不清楚，请让我知道。

答案 2

只是搜索了一些文章，上面的场景肯定可以在Tomcat中使用切换。CrossContext

在上下文中设置以下元素.xml<Context crossContext="true">

然后。getServletContext().getContext("/Web2");

不过，还没有尝试过。