我正在制作Java swing应用程序，客户端可以从服务器下载文件或在那里上传文件。这里，首先客户端需要在服务器中创建一个帐户，该帐户将在服务器PC中创建一个文件夹。之后，客户将登录他/她的帐户。如果登录成功，则客户端将看到该文件夹中的文件，并可以下载文件或将文件上载到该文件夹。现在，当我尝试下载文件时，download()方法卡在某一行（第85行）。现在可以解决什么问题呢？
这是我的代码：
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package registration;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import javax.swing.*;
import java.net.*;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Registration {
/**
* @param args the command line arguments
*/
static String str, name, path = "", h, arr[];
static boolean flag, flag2 = false, flag_array[],connection = false, response = false, response2 = false;
static File file, file2, f;
static Socket client;
static DataInputStream is;
static DataOutputStream os;
static int k;
static class Handle implements Runnable
{
Thread t;
JButton bn;
boolean flag;
public Handle(JButton button,boolean flag)
{
t = new Thread(this);
bn = button;
this.flag = flag;
t.start();
}
public static void download(int i)
{
try {
os.writeBytes(arr[i]+"->download\n");
int filesize=1022386;
int bytesRead;
int currentTot = 0;
byte [] bytearray = new byte [filesize];
InputStream ist = client.getInputStream();
File fi = new File(arr[i]);
fi.createNewFile();
FileOutputStream fos = new FileOutputStream(fi,false);
BufferedOutputStream bos = new BufferedOutputStream(fos);
bytesRead = ist.read(bytearray,0,bytearray.length);
currentTot = bytesRead;
do {
bytesRead =
ist.read(bytearray, currentTot, (bytearray.length-currentTot));
if(bytesRead >= 0) currentTot += bytesRead;
} while(bytesRead > -1);
System.out.println("Done");
bos.write(bytearray, 0 , currentTot);
bos.flush();
bos.close();
System.out.println("Done again");
} catch (IOException ex) {
Logger.getLogger(Registration.class.getName()).log(Level.SEVERE, null, ex);
}
}
@Override
public void run()
{
while(flag)
{
bn.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
System.out.println(k + " "+arr[k]);
download(k);
System.out.println("Done");
}
});
}
}
}
public static boolean logIn()
{
JFrame frame = new JFrame("Log In");
frame.setSize(700,500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
JLabel label1 = new JLabel("Username: ");
frame.add(label1,gbc);
gbc.gridx = 1;
gbc.gridy = 0;
JTextField tf1 = new JTextField(20);
frame.add(tf1,gbc);
gbc.gridy++;
gbc.gridx = 0;
JLabel label2 = new JLabel("Password: ");
frame.add(label2,gbc);
gbc.gridx = 1;
gbc.gridy = 1;
JTextField tf2 = new JTextField(20);
frame.add(tf2,gbc);
gbc.gridx = 0;
gbc.gridy = 2;
gbc.gridwidth = 3;
JButton button = new JButton("Log in");
frame.add(button,gbc);
frame.pack();
frame.setResizable(true);
frame.setVisible(true);
button.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
try {
os.writeBytes(tf1.getText() + "->"+tf2.getText()+"\n");
String line = is.readLine();
if(line.equals("Accepted") == true)
flag2 = true;
else
JOptionPane.showMessageDialog(frame, "Invalid Username or Password", "Error", JOptionPane.ERROR_MESSAGE);
response = true;
} catch (IOException ex) {
Logger.getLogger(Registration.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
while(true)
{
if(response == true)
break;
}
return flag2;
}
/*public static void download(int i)
{
try {
os.writeBytes(arr[i]+" download\n");
int filesize=1022386;
int bytesRead;
int currentTot = 0;
byte [] bytearray = new byte [filesize];
InputStream ist = client.getInputStream();
FileOutputStream fos = new FileOutputStream(arr[i]);
BufferedOutputStream bos = new BufferedOutputStream(fos);
bytesRead = ist.read(bytearray,0,bytearray.length);
currentTot = bytesRead;
do {
bytesRead =
ist.read(bytearray, currentTot, (bytearray.length-currentTot));
if(bytesRead >= 0) currentTot += bytesRead;
} while(bytesRead > -1);
bos.write(bytearray, 0 , currentTot);
bos.flush();
bos.close();
} catch (IOException ex) {
Logger.getLogger(Registration.class.getName()).log(Level.SEVERE, null, ex);
}
}*/
public static void pass(String line) throws FileNotFoundException
{
JFileChooser fc = new JFileChooser();
arr = line.split(",");
JFrame frame = new JFrame("Welcome");
frame.setSize(700,500);
JMenuBar menubar = new JMenuBar();
frame.setJMenuBar(menubar);
JMenu account = new JMenu("Account");
menubar.add(account);
JMenuItem up_file = new JMenuItem("Upload File");
JMenuItem logout = new JMenuItem("Log out");
account.add(up_file);
account.add(logout);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
int c = arr.length;
flag_array = new boolean[c];
for(int i = 0;i < c;i++)
flag_array[i] = true;
JButton button[] = new JButton[c];
JLabel label[] = new JLabel[c];
gbc.gridx = 0;
gbc.gridy = 0;
for(int i = 0;i < c;i++)
{
label[i] = new JLabel(arr[i]);
gbc.insets = new Insets(10,0,0,0);
gbc.ipadx = 20;
frame.add(label[i],gbc);
gbc.insets = new Insets(10,0,0,0);
gbc.gridx++;
button[i] = new JButton("Download File");
frame.add(button[i],gbc);
gbc.gridx = 0;
gbc.gridy++;
}
frame.pack();
JButton ok;
JTextField tf = new JTextField(15);
ok = new JButton("OK");
frame.setVisible(true);
frame.setResizable(true);
up_file.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
int returnVal = fc.showOpenDialog(frame);
if (returnVal == JFileChooser.APPROVE_OPTION) {
file2 = fc.getSelectedFile();
path = file2.getAbsolutePath();
JFrame frame = new JFrame("Browse File");
frame.setSize(700,500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(tf);
frame.add(ok);
frame.pack();
tf.setText(path);
frame.setResizable(true);
frame.setVisible(true);
}
}
});
ok.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
try {
String line = file2.getName();
os.writeBytes(line + "->upload\n");
System.out.println("Accepted connection : " + client);
File transferFile = new File (path);
byte [] bytearray = new byte [(int)transferFile.length()];
FileInputStream fin = new FileInputStream(transferFile);
BufferedInputStream bin = new BufferedInputStream(fin);
bin.read(bytearray,0,bytearray.length);
OutputStream ost = client.getOutputStream();
System.out.println("Sending Files...");
ost.write(bytearray,0,bytearray.length);
ost.flush();
System.out.println("File transfer complete");
} catch (IOException ex) {
Logger.getLogger(Registration.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
Handle h[] = new Handle[c];
for(int i = 0;i < c;i++)
{
h[i] = new Handle(button[i],flag_array[i]);
/*k = i;
button[i].addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
System.out.println(k + " "+arr[k]);
download(k);
System.out.println("Done");
}
});*/
}
/*for(int i = 0;i < c;i++)
{
if(flag_array[i] == true)
download(i);
}*/
logout.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
try {
os.writeBytes("Bye\n");
connection = true;
response2 = true;
for(int i = 0;i < c;i++)
{
flag_array[i] = false;
try {
h[i].t.join();
} catch (InterruptedException ex) {
Logger.getLogger(Registration.class.getName()).log(Level.SEVERE, null, ex);
}
}
client.close();
frame.dispose();
} catch (IOException ex) {
Logger.getLogger(Registration.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
/*button.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
String string = tf.getText();
if(path.length() == 0)
{
if(string.equals(arr[1]) == true)
{
File folder = new File("G:/Java Programming/Input files/"+arr[0]);
File[] listOfFiles = folder.listFiles();
for (File fi : listOfFiles) {
if (fi.isFile()) {
fi.setExecutable(true);
fi.setReadable(true);
fi.setWritable(true);
}
}
}
}
else
{
Path source = Paths.get(path);
h = tf3.getText();
Path dest = Paths.get(h);
try {
Files.copy(source, dest.resolve(source.getFileName()));
} catch (IOException ex) {
ex.printStackTrace();
}
if(string.equals(arr[1]) == true)
{
File folder = new File("G:/Java Programming/Input files/"+arr[0]);
File[] listOfFiles = folder.listFiles();
for (File fi : listOfFiles) {
if (fi.isFile()) {
fi.setExecutable(true);
fi.setReadable(true);
fi.setWritable(true);
}
}
}
}
}
});
b2.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
String string = tf.getText();
if(path.length() == 0)
{
if(string.equals(arr[1]) == true)
{
File folder = new File("G:/Java Programming/Input files/"+arr[0]);
File[] listOfFiles = folder.listFiles();
for (File fi : listOfFiles) {
if (fi.isFile()) {
fi.setExecutable(false);
fi.setReadable(false);
fi.setWritable(false);
}
}
}
}
else
{
Path source = Paths.get(path);
h = tf3.getText();
Path dest = Paths.get(h);
try {
Files.copy(source, dest.resolve(source.getFileName()));
} catch (IOException ex) {
ex.printStackTrace();
}
if(string.equals(arr[1]) == true)
{
File folder = new File("G:/Java Programming/Input files/"+arr[0]);
File[] listOfFiles = folder.listFiles();
for (File fi : listOfFiles) {
if (fi.isFile()) {
fi.setExecutable(false);
fi.setReadable(false);
fi.setWritable(false);
}
}
}
}
}
});*/
while(true)
{
if(response2 == true)
break;
}
}
public static void main(String[] args) throws IOException {
client = new Socket("127.0.0.1", 1234);
os = new DataOutputStream(client.getOutputStream());
is = new DataInputStream(client.getInputStream());
file = new File("G:/Java Programming/Input files/28/form.txt");
if(file.exists())
{
if(logIn())
{
String line = is.readLine();
pass(line);
}
}
else
{
JFrame frame = new JFrame("Registration Form");
JPanel p = new JPanel();
frame.setSize(700,500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GridBagConstraints gbc = new GridBagConstraints();
GridLayout g = new GridLayout(1, 3);
JLabel label1, label2, label3, label4, label5, label6;
label1 = new JLabel("Name: ");
JTextField tf1, tf2, tf3;
JTextArea ta;
tf1 = new JTextField(25);
label2 = new JLabel("Roll: ");
tf2 = new JTextField(10);
label3 = new JLabel("Address: ");
ta = new JTextArea(5,30);
p.setLayout(new GridBagLayout());
gbc.gridx = 0;
gbc.gridy = 0;
//label1.getPreferredSize();
p.add(label1, gbc);
gbc.gridx = 1;
p.add(tf1, gbc);
gbc.gridx = 2;
gbc.insets = new Insets(0,1,0,0);
p.add(label2, gbc);
gbc.gridx = 3;
p.add(tf2, gbc);
gbc.gridx = 0;
gbc.gridy = 1;
gbc.ipady = 30;
gbc.anchor = GridBagConstraints.BASELINE_LEADING;
gbc.fill = GridBagConstraints.HORIZONTAL;
p.add(label3, gbc);
gbc.gridx = 1;
gbc.gridy = 1;
gbc.ipadx = 10;
gbc.gridwidth = 3;
gbc.fill = GridBagConstraints.BOTH;
p.add(ta, gbc);
label4 = new JLabel("Gender:");
JCheckBox cb1 = new JCheckBox("Male");
JCheckBox cb2 = new JCheckBox("Female");
gbc.gridx = 0;
gbc.gridy = 2;
p.add(label4,gbc);
gbc.gridx++;
p.add(cb1,gbc);
gbc.gridx+=3;
p.add(cb2,gbc);
label5 = new JLabel("Hobby");
String s[] = {"Playing games", "Watching movies", "Solving problems"};
JComboBox<String> cox = new JComboBox<>(s);
gbc.gridx = 0;
gbc.gridy++;
p.add(label5,gbc);
gbc.gridx++;
gbc.gridwidth = 3;
p.add(cox,gbc);
gbc.gridx = 0;
gbc.gridy++;
label6 = new JLabel("Password: ");
p.add(label6, gbc);
gbc.gridx++;
gbc.insets = new Insets(0,14,0,0);
tf3 = new JTextField(20);
p.add(tf3, gbc);
gbc.gridy++;
JButton button = new JButton("Submit");
gbc.insets = new Insets(0,180,0,180);
p.add(button,gbc);
frame.add(p);
frame.pack();
button.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e)
{
try {
name = tf1.getText();
str = tf2.getText();
File dir = new File("G:/Java Programming/Input files/"+str);
dir.mkdirs();
file = new File(dir,"form.txt");
FileWriter fout = new FileWriter(file);
FileWriter fout2 = new FileWriter("G:/Java Programming/Input files/Passwords.txt");
fout.write("Name: "+name+"\n");
fout.write("Roll no.: "+str+"\n");
fout2.write(str+" ");
str = ta.getText();
fout.write("Address: "+str+"\n");
flag = cb1.isSelected();
if(flag == true)
fout.write("Gender: Male\n");
else
fout.write("Address: Female\n");
str = (String) cox.getSelectedItem();
fout.write("Hobby: "+str+"\n");
fout.close();
str = tf3.getText();
fout2.write(str+" form.txt");
file.setExecutable(false);
file.setReadable(false);
file.setWritable(false);
fout2.close();
} catch (IOException ex) {
Logger.getLogger(Registration.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
frame.setVisible(true);
frame.setResizable(true);
}
/*int c = flag_array.length;
for(int i = 0;i < c;i++)
{
if(flag_array[i] == true)
download(i);
}*/
if(connection == false)
{
os.writeBytes("Bye\n");
client.close();
}
}
}
这是服务器端代码：
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package sdpserver;
import java.net.*;
import java.io.*;
import java.util.Scanner;
public class SDPServer {
/**
* @param args the command line arguments
*/
static ServerSocket server;
static DataOutputStream os;
static DataInputStream is;
static Socket client;
static String arr[];
public static void download(String str) throws IOException
{
System.out.println("Accepted connection : " + client);
File transferFile = new File ("G:\\Java Programming\\Input files\\"+arr[2]+"\\"+str);
byte [] bytearray = new byte [(int)transferFile.length()];
FileInputStream fin = new FileInputStream(transferFile);
BufferedInputStream bin = new BufferedInputStream(fin);
bin.read(bytearray,0,bytearray.length);
OutputStream ost = client.getOutputStream();
System.out.println("Sending Files...");
ost.write(bytearray,0,bytearray.length);
ost.flush();
System.out.println("File transfer complete");
}
public static void upload(String str) throws FileNotFoundException, IOException
{
int filesize=1022386;
int bytesRead;
int currentTot = 0;
byte [] bytearray = new byte [filesize];
InputStream ist = client.getInputStream();
FileOutputStream fos = new FileOutputStream("G:\\Java Programming\\Input files\\"+arr[2]+str);
BufferedOutputStream bos = new BufferedOutputStream(fos);
bytesRead = is.read(bytearray,0,bytearray.length);
currentTot = bytesRead;
do {
bytesRead =
ist.read(bytearray, currentTot, (bytearray.length-currentTot));
if(bytesRead >= 0) currentTot += bytesRead;
} while(bytesRead > -1);
bos.write(bytearray, 0 , currentTot);
bos.flush();
bos.close();
}
public static void main(String[] args)throws IOException {
server = new ServerSocket(1234);
FileReader fin = new FileReader("G:\\Java Programming\\Input files\\Passwords.txt");
Scanner b = new Scanner(fin);
String s,req[], files[], names, down[], up[];
int c;
File folder = null;
boolean flag = false;
client = server.accept();
is = new DataInputStream(client.getInputStream());
os = new DataOutputStream(client.getOutputStream());
while(true)
{
String line = is.readLine();
if(line.contains("download"))
{
down = line.split("->");
download(down[0]);
}
else if(line.contains("upload"))
{
up = line.split("->");
upload(up[0]);
}
else
{
if(line.equals("Bye"))
break;
req = line.split("->");
while(b.hasNextLine())
{
s = b.nextLine();
arr = s.split("->");
if((req[0].equals(arr[0])) && (req[1].equals(arr[1])))
{
os.writeBytes("Accepted\n");
folder = new File("G:/Java Programming/Input files/"+arr[2]);
flag = true;
break;
}
}
if(flag == false)
{
os.writeBytes("Invalid Username or Password\n");
continue;
}
files = folder.list();
c = files.length;
names = files[0];
for(int i = 1;i < c;i++)
{
names = names + "," + files[i];
}
os.writeBytes(names+"\n");
}
}
client.close();
}
}