Question

java 类中HttpServletRequest request为空 困惑

package lee;

import java.io.*;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

public class CreateImage
{

private HttpServletRequest req;

public CreateImage(int width,int height,double a[])
{
... //代码

}

public void drawCurve() throws IOException{

req = ServletActionContext.getRequest();
if(req==null){
System.out.println("null");
}else
{
System.out.println("ok");
}

}

}

相当困惑 得到的req就是为null 求解释

Answer 1

private HttpServletRequest req; 这个不要改成
HttpServletRequest request = ServletActionContext.getRequest();
就可以了！

Answer 2

你在普通类里当然不行了，你得在struts2的action里这么做