如何在Java中访问JSP隐式对象，例如(request，response) [英] How to access JSP implicit objects like (request , response) in Java

问题描述

如何在Java中传递JSP隐式对象，例如(请求，响应). 我想用Java代码访问JSP隐式对象. 请建议如何实现?

How to pass JSP implicit objects like (request, response) in Java. I want to access JSP Implicit Objects in Java code. Please suggest how to achieve this?

我的Java代码是:

package test.here;
import java.sql.*;
import java.util.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.ibm.commerce.server.WcsApp;
import com.ibm.commerce.server.JSPHelper;

public class SomeBean {
  String punchOutRes = null;
  HttpServletResponse response;
  HttpServletRequest request; 

  public String getPunchOutRes() {         
    response.setContentType("text/xml");
    return "testing";      
  } 
}

在这里，当我尝试在请求和响应中设置或获取任何内容时，我会得到NUllPointerException.

Here when I am trying to set or get anything in request and response, I get NUllPointerException.

推荐答案

您可以使用<jsp:setProperty和EL表达式将对象传递给Bean.您必须为getter和setter方法修改bean.

You can pass objects to the bean using <jsp:setProperty and EL expressions. You have to modify the bean for getter and setter methods.

public class SomeBean {
  String punchOutRes = null;
  HttpServletResponse response;
  HttpServletRequest request;

  public HttpServletResponse getResponse() {
    return response;
  }

  public void setResponse(HttpServletResponse response) {
    this.response = response;
    try {
      response.getWriter().println("Some Output");
    } catch (IOException e) {
      e.printStackTrace();  
    }
  }

  public HttpServletRequest getRequest() {
    return request;
  }

  public void setRequest(HttpServletRequest request) {
    this.request = request;
  }

  public String getPunchOutRes() {
    response.setContentType("text/xml");
    return "testing";
  }
}

然后在JSP中使用

<jsp:useBean id="someBean" class="beans.SomeBean" scope="request"/>
<jsp:setProperty name="someBean" property="request" value="${pageContext.request}"/>
<jsp:setProperty name="someBean" property="response" value="${pageContext.response}"/>

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