struts项目向前台返回图片。

Posted 2020-09-24 valarchie

读取项目路径WebRoot下的图片

编写action

package com.sadj.market.action;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;

public class PublicAction extends ActionSupport{
    //定义输出到前台的输出流
    private ByteArrayInputStream imageStream;  
    
    private Logger logger=LoggerFactory.getLogger(Public.class);
    private static final long serialVersionUID = 1L;
    
    public String image() throws IOException{
        HttpServletRequest request = ServletActionContext.getRequest();
        //获取webroot下的文件
        String path   =   request.getSession().getServletContext().getRealPath("/")+"statics\\x.jpg";
        System.out.println(path);
        
        //创建文件输入流
        FileInputStream fis = new  FileInputStream(path);
        //放入bufferedInputStream 
        BufferedInputStream bis=new BufferedInputStream(fis);
        //定义ByteArrayOutStream
        ByteArrayOutputStream output = new ByteArrayOutputStream(); 
        
        int c=bis.read();//读取bis流中的下一个字节
        while(c!=-1){
            output.write(c);
            c=bis.read();
        }
        
        bis.close();
        
        imageStream = new ByteArrayInputStream(output.toByteArray());
        
        return SUCCESS;
    }

    public ByteArrayInputStream getImageStream() {
        return imageStream;
    }

    public void setImageStream(ByteArrayInputStream imageStream) {
        this.imageStream = imageStream;
    }
    
    

}

编写struts.xml

<action name="image" class="com.sadj.market.action.PublicAction" method="image">
            <result name="success" type="stream">
                <param name="contentType">image/jpeg</param>  
                <param name="inputName">imageStream</param>  
                <param name="bufferSize">2048</param>  
            </result>
      </action>

前台直接访问image这个action即可