如何实现,实时显示网页聊天时对方实时输入的内容,不管是否发送。

如何实现,实时显示网页聊天时对方实时输入的内容,不管是否发送。
需求描述：

原型图片：

那你这不就相当于已经发送了吗，就是允许修改，类似于TIM中联网文档的编写

没执行一次onkeyup操作就调用一次接口，把内容传送到你的界面。类似于限制字数的，不过它是获取字数，你可以在对input框输入字符时，就调用接口。

这个实现完全没有意义啊，显示正在输入是一定要有不发送的情况的。

这样的话，要是修改会显示成什么样？

keyup事件，对方一边编辑一边发送就行了

package www.test;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;

import org.apache.catalina.websocket.MessageInbound;
import org.apache.catalina.websocket.StreamInbound;
import org.apache.catalina.websocket.WebSocketServlet;
import org.apache.catalina.websocket.WsOutbound;

@WebServlet("/chat")
public class ChatWebSocketServlet extends WebSocketServlet {
private final Map map = new HashMap();
private static final long serialVersionUID = -1058445282919079067L;
@Override
protected StreamInbound createWebSocketInbound(String arg0, HttpServletRequest request) {
// StreamInbound：基于流的WebSocket实现类(带内流)，应用程序应当扩展这个类并实现其抽象方法onBinaryData和onTextData。
return new ChatMessageInbound();
}
class ChatMessageInbound extends MessageInbound {
// MessageInbound：基于消息的WebSocket实现类(带内消息)，应用程序应当扩展这个类并实现其抽象方法onBinaryMessage和onTextMessage。
@Override
protected void onOpen(WsOutbound outbound) {
map.put(outbound.hashCode(), outbound);
super.onOpen(outbound);
}
@Override
protected void onClose(int status) {
map.remove(getWsOutbound().hashCode());
super.onClose(status);
}
@Override
protected void onBinaryMessage(ByteBuffer buffer) throws IOException {
}
@Override
protected void onTextMessage(CharBuffer buffer) throws IOException {
String msg = buffer.toString();
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss.SSS");
msg = " 匿名用戶 " + sdf.format(date) + "
" + msg;
broadcast(msg);
}
private void broadcast(String msg) {
Set set = map.keySet();
for (Integer integer : set) {
WsOutbound outbound = map.get(integer);
CharBuffer buffer = CharBuffer.wrap(msg);
try {
outbound.writeTextMessage(buffer);
outbound.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}

package www.test;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;

import org.apache.catalina.websocket.MessageInbound;
import org.apache.catalina.websocket.StreamInbound;
import org.apache.catalina.websocket.WebSocketServlet;
import org.apache.catalina.websocket.WsOutbound;

@WebServlet("/chat")
public class ChatWebSocketServlet extends WebSocketServlet {
private final Map map = new HashMap();
private static final long serialVersionUID = -1058445282919079067L;
@Override
protected StreamInbound createWebSocketInbound(String arg0, HttpServletRequest request) {
// StreamInbound：基于流的WebSocket实现类(带内流)，应用程序应当扩展这个类并实现其抽象方法onBinaryData和onTextData。
return new ChatMessageInbound();
}
class ChatMessageInbound extends MessageInbound {
// MessageInbound：基于消息的WebSocket实现类(带内消息)，应用程序应当扩展这个类并实现其抽象方法onBinaryMessage和onTextMessage。
@Override
protected void onOpen(WsOutbound outbound) {
map.put(outbound.hashCode(), outbound);
super.onOpen(outbound);
}
@Override
protected void onClose(int status) {
map.remove(getWsOutbound().hashCode());
super.onClose(status);
}
@Override
protected void onBinaryMessage(ByteBuffer buffer) throws IOException {
}
@Override
protected void onTextMessage(CharBuffer buffer) throws IOException {
String msg = buffer.toString();
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss.SSS");
msg = " 匿名用戶 " + sdf.format(date) + "
" + msg;
broadcast(msg);
}
private void broadcast(String msg) {
Set set = map.keySet();
for (Integer integer : set) {
WsOutbound outbound = map.get(integer);
CharBuffer buffer = CharBuffer.wrap(msg);
try {
outbound.writeTextMessage(buffer);
outbound.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}

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所用jar包：tomcat中lib下的包就足够用了
再加一个javax.mail

采用websocket