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。