基于Java怎么实现简易的局域网对话系统，相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。
先说一下
写的确实比较一般，别喷
为什么呢，疫情原因，学校提前两周期末考试，时间也不太充足，将就一下
服务器代码：
package xcvcvcx;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;
public class Server {
static int index = 0;
static BufferedWriter[] userWrite = new BufferedWriter[100];
static BufferedReader[] userRead = new BufferedReader[100];
static Socket[] userSocket = new Socket[100];
static String[] userId = new String[100];
static String[] userName = new String[100];
public static void main(String[] args) throws IOException {
ServerSocket ss = new ServerSocket(6666); // 监听指定端口
System.out.println("server is running...");
index = 0;
for (;;) {
Socket sock = ss.accept();
String idd = sock.getRemoteSocketAddress().toString();
System.out.println("connected from " + sock.getRemoteSocketAddress());
userSocket[index] = sock;
Thread t = new Handler(sock);
((Handler) t).userId = idd;
userId[index]=((Handler) t).userId =idd;
t.start();
}
}
}
class Handler extends Thread {
Socket sock;
BufferedWriter writer;
BufferedReader reader;
String username;
String userId;
public Handler(Socket sock) {
this.sock = sock;
}
public void synMessage(Map<String,String> message) throws IOException {
BufferedWriter writer;
BufferedWriter[] user =Server.userWrite;
int isall =1;
String dis = "a";
if ( message.get("messageclass").toString().equals("normally") ){
dis = message.get("distination");
System.out.println(dis);
System.out.println();
if (dis.equals("all") == false){
System.out.println("no isall");
isall= 0;
}
}
int len = Server.index;
for(int i =0; i< len;i++)
{
if (Server.userWrite[i] == null){
continue;
}
System.out.println("vf");
if (isall == 0){
// 专门的消息
if (Server.userName[i].equals(dis)){
message.put( "distinationId",Server.userId[i] );
writer = user[i];
writer.write(message.toString() + "\n");
System.out.print("专门消息发送成功");
writer.flush();
return;
}
continue;
}
message.put( "distinationId",Server.userId[i] );
if (Server.userWrite[i] == null){
continue;
}
if ( Server.userId[i].equals(this.userId) == false)
{
writer = user[i];
writer.write(message.toString() + "\n");
System.out.print("进来了");
writer.flush();
}else {
writer = user[i];
writer.write(message.toString() + "\n");
System.out.print("进来了");
writer.flush();
}
}
}
public void synUserList(Map<String,String> message,String Id){
BufferedWriter writer;
BufferedWriter[] user =Server.userWrite;
// 封装 用户列表
// 规定用户名不可以有空格
int len = Server.index;
String userLis = "here";
for (int i = 0; i< len ; i++)
{
System.out.println(userLis);
if (Server.userWrite[i]!=null){
if (message.get("userId").equals(Server.userId[i])){
continue;
}else {
if (Server.userName[i] ==null){
continue;
}
userLis = userLis + " " + Server.userName[i];
}
}
}
message.put( "distinationId",Id);
message.put( "userList",userLis);
message.put("messageclass","synUserList");
for(int i =0; i< len;i++)
{
if (Server.userWrite[i] == null){
continue;
}
if ( Server.userId[i].equals(Id))
{
writer = user[i];
try {
writer.write(message.toString() + "\n");
writer.flush();
return;
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
@Override
public void run() {
try (InputStream input = this.sock.getInputStream()) {
try (OutputStream output = this.sock.getOutputStream()) {
handle(input, output);
}
} catch (Exception e) {
try {
this.sock.close();
} catch (IOException ioe) {
}
System.out.println("client disconnected.");
}
}
private void handle(InputStream input, OutputStream output) throws IOException {
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(output, StandardCharsets.UTF_8));
BufferedReader reader = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8));
this.writer = writer;
this.reader = reader;
int inde = Server.index;
Server.index++;
Server.userRead[inde] = reader;
Server.userWrite[inde] = writer;
Map<String,String> message= new HashMap<String, String>();
message.put("messageclass", "synId");// 普通 消息
message.put( "userId",userId );
message.put( "userIndex",String.valueOf(inde) );
String to=message.toString();
writer.write(to+'\n');
writer.flush();
for (;;) {
String s = reader.readLine();
if (s == null){
continue;
}
// System.out.print(s);
// synMessages(s);
Map<String, String> mess= Client.mapStringToMap(s);
//// System.out.print(s);
if(mess.get("messageclass").toString().equals("normally"))
{
System.out.print("irieowmxn");
synMessage(mess);
continue;
}else if (mess.get("messageclass").toString().equals("synUserName")){
System.out.println("now synuser");
String id = mess.get("userId");
System.out.println(mess.toString());
username = mess.get("user");
int index = Integer.parseInt( mess.get("userIndex") );
Server.userName[index] = username;
// 同步 在线用户
Map<String,String> synuser= new HashMap<String, String>();
synuser.put("messageclass", "addUser");// 普通 消息
synuser.put( "userName",username );
synMessage(synuser);
// 同步所以已在线用户， 有新用户 登录
// 其实 我们还需要 回复 该用户， 现在有哪些在线 以便于 后来登录的人 用户列表 无法更新
synUserList(message,id);
continue;
}else if ( mess.get("messageclass").toString().equals("userClose") ){
Map<String,String> synuser= new HashMap<String, String>();
synuser.put("messageclass", "userClose");// 普通 消息
synuser.put( "userName",username );
synMessage(synuser);
int iin = Integer.parseInt(mess.get("userIndex"));
Server.userWrite[iin] = null;
}
if (s.equals("bye")) {
writer.write("bye\n");
writer.flush();
break;
}
}
}
}客户端：
package xcvcvcx;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.SocketAddress;
import java.nio.charset.StandardCharsets;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.WindowConstants;
public class Client extends JFrame implements ActionListener ,ItemListener {
private String currentt_userName = null;
//各种组件
JLabel jLabelSeverIP,jLabelSeverPort,jLabelReceiveData,jLabelSentData;
JTextField jTextFieldSeverIP,jTextFieldSeverPort,jTextFieldSentData;
JButton jButtonSetupSever,jButtonCloseNetwork,jButtonSent;
JTextArea jTextAreaReceiveData;
JButton jButtonExit;
// 当前在线用户部分
JLabel jLabelOnlinUser;
JComboBox jComboBoxOnlineUser;
//组件完毕
BufferedReader reader;
BufferedWriter writer;
// 存储用户信息
JLabel jLabelusername;
JTextField jTextFieldusername;
String userId ;
Socket sock;
int userIndex;
// 服务连接相关
String ServerAddress ="192.168.43.240" ; // 可以自己设置
int port = 6666;
public Client(){
init();
}
public void init(){
//初始化
jLabelReceiveData=new JLabel("接受数据:");
jLabelSentData=new JLabel("发送数据:");
jLabelSeverIP=new JLabel("服务器IP");
jLabelSeverPort=new JLabel("服务器端口");
jTextFieldSentData=new JTextField(15);
jTextFieldSeverIP=new JTextField(7);
jTextFieldSeverPort=new JTextField(7);
jButtonCloseNetwork=new JButton("关闭服务");
jButtonSent=new JButton("发送");
jButtonSetupSever=new JButton("开启服务");
jTextAreaReceiveData=new JTextArea(20,15);
JScrollPane scroller = new JScrollPane(jTextAreaReceiveData);
scroller.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
jTextAreaReceiveData.setWrapStyleWord(true);//设置单词在一行不足容纳时换行
jTextAreaReceiveData.setLineWrap(true);//设置文本编辑区自动换行默认为true,即会"自动换行"
//this.add(editArea,BorderLayout.CENTER);//向窗口添加文本编辑区
jButtonExit = new JButton("退出");
//组件初始化
// 存储 用户信息
jLabelusername = new JLabel("用户名");
jTextFieldusername = new JTextField(10);
jLabelOnlinUser = new JLabel("在线用户");
jComboBoxOnlineUser = new JComboBox();
jComboBoxOnlineUser.addItemListener(this::itemStateChanged);
jComboBoxOnlineUser.addItem("self");
JPanel panel1=new JPanel();
panel1.setLayout(new FlowLayout());
panel1.add(jLabelSeverIP);
panel1.add(jTextFieldSeverIP);
panel1.add(jLabelSeverPort);
panel1.add(jTextFieldSeverPort);
panel1.add(jButtonSetupSever);
panel1.add(jButtonCloseNetwork);
JPanel panel2=new JPanel();
panel2.add(jLabelReceiveData);
JPanel jPaneluserinfor = new JPanel();
jPaneluserinfor.setLayout(new FlowLayout());
jPaneluserinfor.add(jLabelusername);
jPaneluserinfor.add((jTextFieldusername));
jPaneluserinfor.add(jLabelOnlinUser);
jPaneluserinfor.add(jComboBoxOnlineUser);
JPanel jPanel1=new JPanel();
jPanel1.setLayout(new GridLayout(3,1));
jPanel1.add(panel1);
jPanel1.add(jPaneluserinfor);
jPanel1.add(panel2);
JPanel panel3=new JPanel();
panel3.setLayout(new FlowLayout());
panel3.add(jLabelSentData);
JPanel panel4=new JPanel();
panel4.setLayout(new FlowLayout());
panel4.add(jTextFieldSentData);
panel4.add(jButtonSent);
panel4.add(jButtonExit);
JPanel jPanel2=new JPanel();
jPanel2.setLayout(new GridLayout(2,1));
jPanel2.add(panel3);
jPanel2.add(panel4);
JPanel jPanel=new JPanel();
jPanel.setLayout(new BorderLayout());
jPanel.add(jPanel1,BorderLayout.NORTH);
jPanel.add(scroller,BorderLayout.CENTER);
jPanel.add(jPanel2,BorderLayout.SOUTH);
//完成组件组合
jButtonSent.addActionListener(this);
jButtonSetupSever.addActionListener(this);
jButtonCloseNetwork.addActionListener(this);
jButtonExit.addActionListener(this);
setSize(600,400);
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
add(jPanel);
setVisible(true);
//显示
jButtonCloseNetwork.setEnabled(false);
jTextFieldSeverIP.setText(ServerAddress);
jTextFieldSeverPort.setText(String.valueOf(port));
jTextAreaReceiveData.append("本程序只用于简单演示，\n若要修改服务器地址或端口，请修改指定代码，暂不支持手动指定\n\n\n");
// 连接服务器
try {
Socket sock = new Socket(ServerAddress, port);
this.sock = sock;
try (InputStream input = sock.getInputStream()) {
try (OutputStream output = sock.getOutputStream()) {
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(output, StandardCharsets.UTF_8));
BufferedReader reader = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8));
SocketAddress id = sock.getRemoteSocketAddress();
userId = sock.getRemoteSocketAddress().toString();
this.writer =writer;
this.reader = reader;
while(true)
for (; ; ) {
String resp = reader.readLine();
while (resp == null) {
resp = reader.readLine();
}
System.out.println("<<< " + resp);
Map<String, String> message = mapStringToMap(resp);
if (message.get("messageclass").equals("synId")) {
System.out.println(userId);
userId = message.get("userId");
System.out.println(message.keySet());
System.out.println(userId);
// 更新 服务器 接口 处的 内容
jTextAreaReceiveData.append("已为您成功分配id 请填写用户名，并开启服务");
jTextAreaReceiveData.append(resp);
jTextAreaReceiveData.append("\n");
userIndex = Integer.parseInt(message.get("userIndex"));
continue;
} else if (message.get("messageclass").equals("normally")) {
resp = message.toString();
System.out.print("748328");
// 正常消息
String showMess = "";
String dist = message.get("distination");
if (dist.equals("all")){
showMess = showMess.concat("消息类型:全体消息" + '\n');
}else {
showMess = showMess.concat("消息类型:私发消息" + '\n');
}
showMess = showMess.concat("消息时间: " + message.get("time") + '\n');
showMess = showMess.concat("消息内容: " + message.get("content") + '\n');
showMess = showMess.concat("消息来源: " + message.get("user") + '\n');
jTextAreaReceiveData.append(showMess);
jTextAreaReceiveData.append("\n\n");
} else if (message.get("messageclass").equals("addUser")) {
if (currentt_userName ==null){
continue;
}
System.out.println(message.toString());
String newname = message.get("userName");
if (newname.equals(currentt_userName) == false) {
jComboBoxOnlineUser.addItem(newname);
jTextAreaReceiveData.append("有新用户上线了：他是: " + newname + "\n\n" );
}
} else if (message.get("messageclass").toString().equals("userClose")) {
String name = message.get("userName");
System.out.println("现在 删除 user: " + name);
jTextAreaReceiveData.append("有用户下线了：他是: " + name + "\n\n" );
jComboBoxOnlineUser.removeItem(name);
}else if( message.get("messageclass").toString().equals("synUserList") ){
String Lis = message.get("userList");
String[] UserList = Lis.split(" ");
int i;
for(i=1; i<UserList.length;i++) {
jComboBoxOnlineUser.addItem(UserList[i]);
}
}
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static Map<String,String> mapStringToMap(String str){
str=str.substring(1, str.length()-1);
System.out.println("ishere dk->" + str);
String[] strs=str.split(",");
Map<String,String> map = new HashMap<String, String>();
for (String string : strs) {
String key=string.split("=")[0];
String value=string.split("=")[1];
value = value.trim();
key = key.trim();
map.put(key, value);
}
return map;
}
public static void main(String[] args) throws IOException {
Client a = new Client();
}
private static void handle(InputStream input, OutputStream output) throws IOException {
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(output, StandardCharsets.UTF_8));
BufferedReader reader = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8));
Scanner scanner = new Scanner(System.in);
System.out.println("[server] " + reader.readLine());
for (;;) {
System.out.print(">>> "); // 打印提示
String s = scanner.nextLine(); // 读取一行输入
writer.write(s);
writer.newLine();
writer.flush();
String resp = reader.readLine();
System.out.println("<<< " + resp);
if (resp.equals("bye")) {
break;
}
}
}
void update() throws IOException {
for (;;) {
System.out.print("lkdfvmndfjk");
String resp = reader.readLine();
System.out.println("<<< " + resp);
jTextAreaReceiveData.append(resp);
if (resp.equals("bye")) {
break;
}
}
}
static String time (){
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
return df.format( new Date() ).toString();
}
@Override
public void actionPerformed(ActionEvent e) {
if (e.getSource()==jButtonSent){
if (jTextFieldSentData.getText() == "") {
jTextAreaReceiveData.append("发送不可为空"+"\n");
}else {
this.currentt_userName = jTextFieldusername.getText().toString();
Map<String,String> message= new HashMap<String, String>();
message.put("messageclass", "normally");// 普通 消息
message.put("user",currentt_userName);
message.put( "userId",userId );
String to=jTextFieldSentData.getText();
message.put("content",to);
message.put("time",time());
String distina = jComboBoxOnlineUser.getSelectedItem().toString();
if (distina.equals("self")){
// 发给所有人
System.out.println("查看");
message.put("distination","all");
}else {
// 发给某人
message.put("distination",distina);
}
String ans = message.toString();
to = ans;
try {
writer.write(to+"\n");
writer.flush();
}catch (Exception ee){
System.out.println(ee.toString());
jTextAreaReceiveData.append("发送失败"+"\n");
}
}
}else if (e.getSource() == jButtonCloseNetwork){
try {
sock.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}else if(e.getSource() == jButtonSetupSever){
String name = jTextFieldusername.getText();
if (name.equals("")){
jTextAreaReceiveData.append("用户名不可为空");
// 不可为空 提示
return;
}
currentt_userName = name;
Map<String,String> message= new HashMap<String, String>();
message.put("messageclass", "synUserName");// 普通 消息
message.put("user",currentt_userName);
message.put( "userId",userId );
message.put( "userIndex",String.valueOf(userIndex) );
try {
writer.write(message.toString()+"\n");
writer.flush();
jButtonCloseNetwork.setEnabled(true);
jButtonSetupSever.setEnabled(false);
} catch (IOException e1) {
e1.printStackTrace();
}
// 同步 用户名
}else if (e.getSource()== jButtonExit){
// 关闭按钮
Map<String,String> message= new HashMap<String, String>();
message.put("messageclass", "userClose");// 普通 消息
message.put("user",currentt_userName);
message.put( "userId",userId );
message.put( "userIndex",String.valueOf(userIndex) );
try {
writer.write(message.toString()+"\n");
writer.flush();
System.out.println(message.toString());
} catch (IOException e1) {
e1.printStackTrace();
}// 发送下线消息
jComboBoxOnlineUser.removeAllItems();
}
}
@Override
public void itemStateChanged(ItemEvent e) {
}
}里面的ip地址 我写的是我自己的 想改的可以自己改
看完上述内容，你们掌握基于Java怎么实现简易的局域网对话系统的方法了吗？如果还想学到更多技能或想了解更多相关内容，欢迎关注亿速云行业资讯频道，感谢各位的阅读！
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