Question

我一直在研究很多关于servlet的东西，我已经创建了一个应该从我的网络应用程序中获得一些位置，但由于我缺乏servlet的经验，我不知道如何修复它。另外，我不知道我应该在哪里放置我的HTML应用程序，我听说它应该在WebContent文件夹中，并且它就是，但它不起作用。你可以帮帮我吗？

更新：我正在尝试将一些将由我的servlet转换为txt文件的信息上传，以避免每次上传文件：“... 我'我创建了一个应该从我的网络应用程序中获得一些位置 ......“

服务器：Apache Tomcat 7.0
Eclipse EE Mars

提前谢谢。

我的整个项目都在这里：DropBox

PS：我在下面发布的片段只是为了观察，但我不能使用脚本，因为我不拥有图书馆所在的业务，如果你想看到它在这个PostScript上面的链接上查看。< / p>

我的带有AJAX的HTML

<body>
  <div id="navgrid">
    <div id="header">Header</div>
    <div id="tree1">
      <ul class="jqtree_common jqtree-tree">
        <li class="jqtree_common jqtree-folder">
          <div class="jqtree-element jqtree_common"><a class="jqtree_common jqtree-toggler">â–¼</a><span class="jqtree_common jqtree-title jqtree-title-folder">node1</span>
          </div>
          <ul class="jqtree_common ">
            <li class="jqtree_common">
              <div class="jqtree-element jqtree_common"><span class="jqtree-title jqtree_common">child1</span>
              </div>
            </li>
            <li class="jqtree_common">
              <div class="jqtree-element jqtree_common"><span class="jqtree-title jqtree_common">child2</span>
              </div>
            </li>
          </ul>
        </li>
        <li class="jqtree_common jqtree-folder">
          <div class="jqtree-element jqtree_common"><a class="jqtree_common jqtree-toggler">â–¼</a><span class="jqtree_common jqtree-title jqtree-title-folder">node2</span>
          </div>
          <ul class="jqtree_common ">
            <li class="jqtree_common">
              <div class="jqtree-element jqtree_common"><span class="jqtree-title jqtree_common">child3</span>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
  </div>
  <script type="text/javascript">
  </script>

  <script>
    $(document).ready(function() {

      var POSITIONS;

      //var data is a dynamic JSON file that should be created in the backend.
      var data = [{
        label: 'node1',
        id: 1,
        children: [{
          label: 'child1',
          id: 2
        }, {
          label: 'child2',
          id: 3
        }]
      }, {
        label: 'node2',
        id: 4,
        children: [{
          label: 'child3',
          id: 5
        }]
      }];
      $('#tree1').tree({
        data: data,
        autoOpen: true,
        dragAndDrop: true
      });


      console.log($('#tree1').tree('toJson')); //This will give you the loading jqtree structure.

      $('#tree1').bind(
        'tree.move',
        function(event) {
          event.preventDefault();
          // do the move first, and _then_ POST back.
          event.move_info.do_move();
          console.log($(this).tree('toJson')); //this will give you the latest tree.
          POSITIONS = $(this).tree('toJson');
          alert(POSITIONS);
          $.post('http://sistema.agrosys.com.br/sistema/labs/CSS_HTML/', {
            tree: $(this).tree('toJson')
          });
          alert("done"); //this will post the json of the latest tree structure.
        }
      );

      var data = new FormData();
      data.append("JqTree", POSITIONS);
      alert('Sending: ' + POSITIONS);
      $.ajax({
        url: '/JqTree',
        type: 'POST',
        data: data,
        cache: false,
        dataType: 'json',
        processData: false,
        contentType: false,
        success: function(response) {
          alert("file has been successfully sent\n\n" + POSITIONS);
        },
        error: function(jqXHR, textStatus, errorThrown) {
          alert('ERRORS: ' + textStatus);
        }
      });

    });
  </script>
</body>

我的Servlet

import java.io.IOException;
import java.io.PrintWriter;

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

public class Hello extends HttpServlet {
private static final long serialVersionUID = 1L;
public Hello() {}

protected void doGet(HttpServletRequest request, HttpServletResponse     response) throws ServletException, IOException {

    response.setContentType("text/html");
    PrintWriter out=response.getWriter();

    out.print("<html><body>");
    out.print("<h3>Hello Servlet</h3>");
    out.print("</body></html>");
}

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
     String position = request.getParameter("JqTree");

     PrintWriter writer = new PrintWriter("Positions.txt", "UTF-8");
     writer.println(position);
     writer.close();
}

}

和我的web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee"  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">

<display-name>JqTree</display-name>


<welcome-file-list>


<welcome-file>index.html</welcome-file>    
<welcome-file>index.htm</welcome-file>    
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>

<servlet>

<description></description>

<display-name>Hello</display-name>
<servlet-name>Hello</servlet-name>
<servlet-class>Hello</servlet-class>
</servlet>

<servlet-mapping>  
<servlet-name>Hello</servlet-name>
<url-pattern>/Hello</url-pattern>
</servlet-mapping>

</web-app>

Answer 1

您需要将AJAX调用更改为

$.ajax({
    url: '/JqTree/Hello',

其中/JqTree是您的网络应用的上下文根，加上/Hello，这是<url-pattern>文件中Hello Servlet配置的/WEB-INF/web.xml。

您的$.ajax()来电正在使用post，因此您必须记住只会调用doPost()。
您的doPost()无法返回任何输出，但$.ajax()来电需要dataType: 'json'。这有时会导致请求无声地失败。
我相信您正在尝试上传文件。如果是，您只能使用request.getParameter()读取文件内容。您必须以不同的方式编写Servlet代码以处理multipart/form-data，这取决于您是否在Servlet 3.0或2.x容器下运行。

我的ajax POST没有被发送到我的servlet

1 个答案: