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我创建的小程序在小程序查看器中运行时会将图像文件发送到 servlet。但是当我在浏览器中运行它时，它无法将文件发送到 servlet。

我正在使用 Apache HTTPClient 进行文件上传。我的 servlet 在 servlet 包中的一个测试项目中。那么引用它是否正确"http://localhost:8080//test//testServlet"。

为了在网页中使用它，我构建了小程序项目并将 jar 文件粘贴到与我的 jsp 文件相同的位置。我的小程序代码

 package testing;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.UnsupportedEncodingException;
 import javax.swing.JFileChooser;
import javax.swing.JOptionPane;
import javax.swing.table.DefaultTableModel;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.DefaultHttpClient;

  /**
   *
  * @author Computer
 */

 public class Upload extends javax.swing.JApplet  {

/** Initializes the applet Upload **/

@Override
public void init() {
    try {
        java.awt.EventQueue.invokeAndWait(new Runnable() {
            @Override
            public void run() {
                setSize(300,135);
                initComponents();



            }
        });
    } catch (Exception ex) {
        ex.printStackTrace();
    }
}


/** This method is called from within the init() method to
 * initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is
 * always regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    chooser = new javax.swing.JFileChooser();
    jPanel1 = new javax.swing.JPanel();
    jScrollPane1 = new javax.swing.JScrollPane();
    table = new javax.swing.JTable();
    Upload = new javax.swing.JButton();

    jPanel1.setBackground(new java.awt.Color(255, 255, 255));

    table.setModel(new javax.swing.table.DefaultTableModel(
        new Object [][] {

        },
        new String [] {
            "Title 1"
        }
    ));
    jScrollPane1.setViewportView(table);

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 300, javax.swing.GroupLayout.PREFERRED_SIZE)
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 90, javax.swing.GroupLayout.PREFERRED_SIZE)
    );

    Upload.setText("Upload");
    Upload.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            UploadActionPerformed(evt);
        }
    });

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(Upload))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
            .addComponent(Upload)
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
    );
}// </editor-fold>                        


 private static String executeRequest(HttpRequestBase requestBase){
    String responseString = "" ;

    InputStream responseStream = null ;
    HttpClient client = new DefaultHttpClient () ;
    try{
        HttpResponse response = client.execute(requestBase) ;
        if (response != null){
            HttpEntity responseEntity = response.getEntity() ;

            if (responseEntity != null){
                responseStream = responseEntity.getContent() ;
                if (responseStream != null){
                    BufferedReader br = new BufferedReader (new InputStreamReader (responseStream)) ;
                    String responseLine = br.readLine() ;
                    String tempResponseString = "" ;
                    while (responseLine != null){
                        tempResponseString = tempResponseString + responseLine + System.getProperty("line.separator") ;
                        responseLine = br.readLine() ;
                    }
                    br.close() ;
                    if (tempResponseString.length() > 0){
                        responseString = tempResponseString ;
                    }
                }
            }
        }
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } //catch (ClientProtocolException e) {
      //  e.printStackTrace();
    //}
 catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }finally{
        if (responseStream != null){
            try {
                responseStream.close() ;
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    client.getConnectionManager().shutdown() ;

    return responseString ;
}


  public void executeMultiPartRequest(String urlString, File file) {
    HttpClient client = new DefaultHttpClient();
    HttpPost postRequest = new HttpPost (urlString) ;
    try{

        MultipartEntity multiPartEntity = new MultipartEntity () ;


        FileBody fileBody = new FileBody(file, "application/octect-stream") ;
        multiPartEntity.addPart("attachment", fileBody) ;

        postRequest.setEntity(multiPartEntity) ;


        HttpResponse response = client.execute(postRequest);
    }
    catch (Exception ex){
        ex.printStackTrace() ;
    }

    //return executeRequest (postRequest) ;
}



private void UploadActionPerformed(java.awt.event.ActionEvent evt) {                                       

    DefaultTableModel model = (DefaultTableModel) table.getModel();
    int value = chooser.showOpenDialog(this);
    chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);

    if(value == JFileChooser.APPROVE_OPTION)
    {
       System.out.println("Check");
                    File file = chooser.getSelectedFile();
                    String name = file.getName().toLowerCase();
                    if(name.endsWith(".jpg")||name.endsWith(".bmp")||name.endsWith(".png"))
                    {
                        String showpathName = chooser.getSelectedFile().getName();
                        String absolutePathName = file.getAbsolutePath();
                        System.out.println("Absolute path is "+absolutePathName);

                        /***Send For Uploading*****/

                         executeMultiPartRequest("http://localhost:8080//test//testServlet", file) ;
                        // System.out.println("Response : "+response);

                        /***************************/
                        model.addRow(new Object[]{showpathName});

                    }
                    else
                    {
                        JOptionPane.showMessageDialog(this,"Incorrect File Format");
                    }
    }


}                                      



// Variables declaration - do not modify                     
private javax.swing.JButton Upload;
private javax.swing.JFileChooser chooser;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTable table;
// End of variables declaration

 /***************************************************************/
 /************Servlet code***************************************/
package servlet;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStr
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.FilenameUtils;

 /**
  *
 * @author Computer
 */

 public class testServlet extends HttpServlet {

/** 
 * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
  protected void processRequest(HttpServletRequest request, HttpServletResponse    response)
        throws ServletException, IOException, FileUploadException {
    response.setContentType("text/html;charset=UTF-8");
 //   PrintWriter out = response.getWriter();
    try {
        /* TODO output your page here
        out.println("<html>");
        out.println("<head>");
        out.println("<title>Servlet testServlet</title>");  
        out.println("</head>");
        out.println("<body>");
        out.println("<h1>Servlet testServlet at " + request.getContextPath () + "</h1>");
        out.println("</body>");
        out.println("</html>");
         */
        List<FileItem> items = new ServletFileUpload(new DiskFileItemFactory()).parseRequest(request);
        for (FileItem item : items)
        {
            String filename = FilenameUtils.getName(item.getName());
            System.out.println("Filename "+filename);
           FileInputStream fis = (FileInputStream) item.getInputStream();
           int len = (int) item.getSize();
           System.out.println("inputStream"+fis.available());

           OutputStream out = new FileOutputStream(new        File("C:\\Users\\Computer\\Desktop\\client\\imagenew1.jpg"));

            int read = 0;
            byte[] bytes = new byte[1024];

            while ((read = fis.read(bytes)) != -1) {
    out.write(bytes, 0, read);
}

fis.close();
out.flush();
out.close();

System.out.println("New file created!");

        }
    } finally {            

    }
}

// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign    on the left to edit the code.">
/** 
 * Handles the HTTP <code>GET</code> method.
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    try {
        processRequest(request, response);
    } catch (FileUploadException ex) {
        Logger.getLogger(testServlet.class.getName()).log(Level.SEVERE, null, ex);
    }
}

/** 
 * Handles the HTTP <code>POST</code> method.
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    try {
        processRequest(request, response);
    } catch (FileUploadException ex) {
        Logger.getLogger(testServlet.class.getName()).log(Level.SEVERE, null, ex);
    }
}

/** 
 * Returns a short description of the servlet.
 * @return a String containing servlet description
 */
@Override
public String getServletInfo() {
    return "Short description";
}// </editor-fold>

}

}

4

2 回答 2

0

您的小程序需要指向服务器的真实 IP/DNS 而不是本地主机，因为小程序在客户端运行。

于 2012-08-04T10:28:42.850 回答
0

示例代码是：

public Vector PopDat() {
    Vector vf = new Vector();
    try {
        URL studentDBservlet = new URL(
                "http://jahanzeb:8080/servlet/QuerySer?Qname="
                        + ap.getParameter("Per"));
        URLConnection servletConnection = studentDBservlet.openConnection();
        BufferedReader inFromServlet = new BufferedReader(
                new InputStreamReader(servletConnection.getInputStream()));
        String str;
        while (null != ((str = inFromServlet.readLine()))) {
            vf.add(str);
            System.out.println(str);
        }

    } catch (Exception e) {
        System.out.println(e.toString());
    }

    return vf;
}
于 2012-08-04T09:56:15.080 回答