Struts2 使用Jquery+ajax 文件上传

话不多说 直接上代码

前台js：

var formData = new FormData();
formData.append("file1",$("#file1")[0].files[0]);//第一个file1代表后台文件属性名，第二个file1表示html中input的id
$.ajax({
    type:"post",
    url:"ajax/uploadFile",
    data:formData,
    processData : false, 
    contentType : false,
    success : function(res) { 
        console.log(res);
        if(res=="success"){
            $("#labResult").text("文件上传成功");
        }
    }, 
    error : function(msg) { 
        console.log(msg.responsText);
    } 
});

后台java：

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class UploadAction extends ActionSupport{
    private File file1 ; 
    private String file1FileName ;//FileName为固定写法
    public File getFile1() {
        return file1;
    }
    public void setFile1(File file1) {
        this.file1 = file1;
    }
    public String getFile1FileName() {
        return file1FileName;
    }
    public void setFile1FileName(String file1FileName) {
        this.file1FileName = file1FileName;
    } 
    public String uploadFile() throws Exception {  
        
        String path = ServletActionContext.getRequest().getServletContext().getRealPath("/WEB-INF/upload");  
        //查看是否存在目录 不存在则创建
        File file = new File(path);
        //如果目录不存在
        if(!file.exists()){
            file.mkdirs();
        }
        //文件不为空 则上传
        if(file1!=null){
            //输出流  
            OutputStream os = new FileOutputStream(new File(path,file1FileName));  
            //输入流  
            InputStream is = new FileInputStream(file1);  
              
            byte[] buf = new byte[1024];  
            int length = 0 ;  
              
            while(-1 != (length = is.read(buf) ) )  
            {  
                os.write(buf, 0, length) ;  
            }  
            is.close();  
            os.close();  
        }  
        return "success";  
    }  

    public void uploadFile(){
        System.out.println("file1:"+file1+".");
        System.out.println("file1FileName:"+file1FileName+".");
        String path="";
        try {
            path=uploadFile();
            HttpServletResponse response = ServletActionContext.getResponse();
            response.setContentType("text/html;charset=utf-8");
            response.getWriter().write(path);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

struts：

<package name="ajax" extends="json-default" namespace="/ajax">
    <action name="uploadFile" class="包名.UploadAction" method="uploadFile"></action>
</package>

有啥不懂，底下留言。