2022-02-10 Springmvc+Websocket实现Web方式执行系统命令和结果显示

本文在 Springmvc+Websocket 发送JSON消息实例的基础上，添加了异步运行（使用Thread）的自制 Shell 类封装包和异步运行时用到的 AsyncShellCallback.java (它是Shell包里Callback接口的执行类)，主要修改了 Home.jsp 和 WSTextHandler.java。

1. 开发环境

2. 在 IDEA上创建项目

3. 使用 tomcat7-maven-plugin, 将 tomcat 内嵌运行

4. 导入 spring-webmvc, Servlet & JSTL, websocket, fastjson

5. 支持 SpringMVC

6. 支持静态资源 (html/js/css/images)

以上步骤 1 到 6，请参考 Springmvc+Websocket 发送JSON消息实例

7. Shell 类封装包

1) 添加 src/main/java/com/example/shell/Platform.java

package com.example.shell;

public enum Platform {

WINDOWS, LINUX, MACOS

}

2) 添加 src/main/java/com/example/shell/Callback.java

package com.example.shell;

public interface Callback {

public void showMessage(String str) throws Exception;

public void showError(String str) throws Exception;

public void showFinish(String str) throws Exception;

}

3) 添加 src/main/java/com/example/shell/AsyncShellExecute.java

package com.example.shell;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

public class AsyncShellExecute extends Thread {

volatile int processStatus = 0; // 0 - PIPE ready; 1 - PIPE busying; 2 - PIPE stopping;

volatile int closeStatus = 0;

private String strCommand = "";

private Platform platform = null;

public void setCommand(String strCmd, Platform platform) {

this.strCommand = strCmd;

this.platform = platform;

}

@Override

public void run() {

String errorMessage = "";

try {

String strCmd = "";

if (this.platform == Platform.WINDOWS) {

strCmd = "cmd /c " + this.strCommand;

} else if (platform == Platform.MACOS) {

strCmd = this.strCommand;

} else {

strCmd = this.strCommand;

}

this.processStatus = 1;

Runtime rt = Runtime.getRuntime();

Process p = rt.exec(strCmd);

String line;

BufferedReader dataReader = new BufferedReader(new InputStreamReader(p.getInputStream(), "GBK"));

while ((line = dataReader.readLine()) != null) {

if (this.processStatus == 2) {

//System.out.println("ShellAsyncExecute -> run(1): this.processStatus == 2");

break;

}

this.callback.showMessage(line);

}

if (this.processStatus != 2) {

BufferedReader errorReader = new BufferedReader(new InputStreamReader(p.getErrorStream(), "GBK"));

while ((line = errorReader.readLine()) != null) {

if (this.processStatus == 2) {

//System.out.println("ShellAsyncExecute -> run(2): this.processStatus == 2");

break;

}

this.callback.showMessage(line);

}

//System.out.println("AsyncShellExecute -> run(3): this.closeStatus = " + this.closeStatus);

if (this.closeStatus == 0) {

if (this.processStatus != 2) {

int ret = p.waitFor();

if (ret != 0) {

this.callback.showError("Execute '" + this.strCommand + "' failed");

} else {

this.callback.showFinish("Finish after execute '" + this.strCommand + "' successfully");

}

} else {

this.callback.showFinish("Finish after terminate process");

}

p.destroy();

} catch (IOException e) {

errorMessage = e.getMessage();

} catch (Exception e2) {

errorMessage = e2.getMessage();

}

if (!errorMessage.isEmpty() && this.closeStatus == 0) {

try {

this.callback.showError(errorMessage);

} catch (Exception e) {

e.printStackTrace();

}

this.processStatus = 0;

this.closeStatus = 0;

}

public void terminate(int closeStatus) {

if (this.processStatus == 1)

this.processStatus = 2;

this.closeStatus = closeStatus;

}

public int GetProcessStatus() {

return this.processStatus;

}

public Callback callback;

}

8. 支持 spring-websocket

1) 添加 src/main/java/com/example/ws/AsyncShellCallback.java

package com.example.ws;

import java.util.Map;

import java.util.HashMap;

import org.springframework.web.socket.TextMessage;

import org.springframework.web.socket.WebSocketSession;

import com.alibaba.fastjson.JSON;

import com.example.shell.Callback;

public class AsyncShellCallback implements Callback {

private WebSocketSession session = null;

public AsyncShellCallback(WebSocketSession session) {

this.session = session;

}

@Override

public void showMessage(String str) throws Exception {

Map<String, Object> msgMap = new HashMap<>();

msgMap.put("ret", "data");

msgMap.put("message", str);

session.sendMessage(new TextMessage(JSON.toJSON(msgMap).toString()));

}

@Override

public void showError(String str) throws Exception {

Map<String, Object> errMap = new HashMap<>();

errMap.put("ret", "error");

errMap.put("description", str);

session.sendMessage(new TextMessage(JSON.toJSON(errMap).toString()));

}

@Override

public void showFinish(String str) throws Exception {

Map<String, Object> errMap = new HashMap<>();

errMap.put("ret", "finish");

errMap.put("description", str);

session.sendMessage(new TextMessage(JSON.toJSON(errMap).toString()));

}

2) 添加 src/main/java/com/example/ws/WSInterceptor.java

package com.example.ws;

import org.springframework.http.server.ServerHttpRequest;

import org.springframework.http.server.ServerHttpResponse;

import org.springframework.web.socket.WebSocketHandler;

import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;

import java.util.Map;

public class WSInterceptor extends HttpSessionHandshakeInterceptor {

@Override

public boolean beforeHandshake(ServerHttpRequest request,

ServerHttpResponse response,

WebSocketHandler wsHandler,

Map<String, Object> attributes) throws Exception {

return super.beforeHandshake(request, response, wsHandler, attributes);

}

@Override

public void afterHandshake(ServerHttpRequest request,

ServerHttpResponse response,

WebSocketHandler wsHandler,

Exception ex) {

super.afterHandshake(request, response, wsHandler, ex);

}

3) 添加 src/main/java/com/example/ws/WSTextHandler.java

package com.example.ws;

import java.util.List;

import java.util.Map;

import java.util.HashMap;

import java.util.concurrent.CopyOnWriteArrayList;

import org.springframework.web.socket.CloseStatus;

import org.springframework.web.socket.TextMessage;

import org.springframework.web.socket.WebSocketMessage;

import org.springframework.web.socket.WebSocketSession;

import org.springframework.web.socket.handler.TextWebSocketHandler;

import com.alibaba.fastjson.JSON;

import com.alibaba.fastjson.JSONObject;

import com.example.shell.Platform;

import com.example.shell.AsyncShellExecute;

public class WSTextHandler extends TextWebSocketHandler{

private List<WebSocketSession> clientSessions = new CopyOnWriteArrayList<>();

private AsyncShellExecute asyncShellExecute = null;

@Override

public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {

clientSessions.remove(session);

//System.out.println("Client (" + session.getId() + ") closed, status code: " + status.getCode());

if (asyncShellExecute != null) {

asyncShellExecute.terminate(status.getCode());

}

@Override

public void afterConnectionEstablished(WebSocketSession session) throws Exception {

clientSessions.add(session);

//System.out.println("Client (" + session.getId() + ") connected ... ");

}

@Override

public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {

Map<String, Object> retMap = new HashMap<>();

JSONObject recvJson = (JSONObject) JSON.parse(message.getPayload().toString());

String opt = recvJson.getString("operation");

if ("command".equals(opt)) {

JSONObject paramObj = recvJson.getJSONObject("param");

if (paramObj == null) {

retMap.put("ret", "error");

retMap.put("description", "Invalid command format");

session.sendMessage(new TextMessage(JSON.toJSON(retMap).toString()));

return;

}

String osType = paramObj.getString("os_type");

String cmdStr = paramObj.getString("cmd_str");

Platform platform = Platform.LINUX;

if ("windows".equals(osType)) {

platform = Platform.WINDOWS;

}

if (asyncShellExecute == null || asyncShellExecute.GetProcessStatus() == 0) {

asyncShellExecute = new AsyncShellExecute();

asyncShellExecute.callback = new AsyncShellCallback(session);

asyncShellExecute.setCommand(cmdStr, platform);

asyncShellExecute.start();

} else {

retMap.put("ret", "error");

retMap.put("description", "Previous execution process is running, can NOT run two processes at the same time");

session.sendMessage(new TextMessage(JSON.toJSON(retMap).toString()));

}

} else if ("close".equals(opt)) {

if (asyncShellExecute == null || asyncShellExecute.GetProcessStatus() == 0) {

retMap.put("ret", "finish");

retMap.put("description", "Finish directly");

session.sendMessage(new TextMessage(JSON.toJSON(retMap).toString()));

} else {

asyncShellExecute.terminate(0);

}

} else {

retMap.put("ret", "error");

retMap.put("description", "Invalid data format");

session.sendMessage(new TextMessage(JSON.toJSON(retMap).toString()));

}

4) 添加 src/main/java/com/example/ws/WSConfig.java

package com.example.ws;

import org.springframework.context.annotation.Configuration;

import org.springframework.web.socket.config.annotation.EnableWebSocket;

import org.springframework.web.socket.config.annotation.WebSocketConfigurer;

import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;

import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;

@Configuration

@EnableWebSocket

public class WSConfig implements WebSocketConfigurer{

@Override

public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {

registry.addHandler(new WSTextHandler(), "/websocket")

.addInterceptors(new HttpSessionHandshakeInterceptor())

.setAllowedOrigins("*"); // Allow cross site

}

9. 视图和控制器

1) 添加 src/main/webapp/WEB-INF/jsp/home.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" isELIgnored="false" %>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

</head>

<body>

<c:if test="${not empty message}">

<p style="color: blue;">${message}</p>

</c:if>

<p>

<label><strong>System Environment:</strong></label><br>

<option value="windows">Server run on Windows</option>

<option value="linux">Server run on Linux</option>

</select>

</p>

<p>

<label><strong>Command or shell:</strong></label><br>

</p>

<p>

<label><strong>Websocket:</strong></label><br>

<p>

Execute

</button>

Close Websocket

</button>

</p>

</form>

</div>

var globalSocket = null;

$(document).ready(function() {

console.log("Home Page");

changeType();

$("#os_type").change(function(e) {

changeType();

});

function changeType() {

var osType = $("#os_type").val();

var cmdStrNode = $("#cmd_str");

if (osType == "windows") {

cmdStrNode.val("dir C:\\");

} else if (osType == "linux") {

cmdStrNode.val("ls /");

} else {

cmdStrNode.val("ls /");

}

function connectWebsocket() {

var wsUrl = $("#ws_url").val();

if (wsUrl == '') {

alert("Please enter url");

$("#ws_url").focus();

return;

}

if (globalSocket == null) {

$("#cmd_result").html('');

$("#btn_execute").attr("disabled", "disabled");

createWebsocket(wsUrl);

} else {

var data = {

"operation": "command",

"param": {

"os_type": $("#os_type").val(),

"cmd_str": $("#cmd_str").val(),

}

globalSocket.send(JSON.stringify(data));

}

function createWebsocket(url) {

if (globalSocket != null || url == '')

return;

//console.log("createWebsocket(): url = ", url);

globalSocket = new WebSocket(url);

globalSocket.onopen = funcWSOpen;

globalSocket.onclose = funcWSClose;

globalSocket.onerror = funcWSError;

globalSocket.onmessage = funcWSMessage;

}

function closeWebsocket() {

if (globalSocket != null) {

//console.log("closeWebsocket(): send close");

globalSocket.send(JSON.stringify({ "operation": "close"}));

$("#btn_close").attr("disabled", "disabled");

}

function funcWSOpen(e) {

//console.log("funcWSOpen(): ", e);

$("#cmd_result").html("Executing ... <br><br>");

$("#btn_close").removeAttr("disabled");

$("#btn_close").css("display", "");

var data = {

"operation": "command",

"param": {

"os_type": $("#os_type").val(),

"cmd_str": $("#cmd_str").val(),

}

globalSocket.send(JSON.stringify(data));

}

function funcWSClose(e) {

//console.log("funcWSClose(): ", e);

$("#cmd_result").append("<br>Websocket: Close<br>");

$("#btn_execute").removeAttr("disabled");

$("#btn_close").css("display", "none");

globalSocket = null;

}

function funcWSError(e) {

//console.error("funcWSError(): ", e);

$("#cmd_result").append("<br>Websocket: Error<br>");

$("#btn_execute").removeAttr("disabled");

$("#btn_close").css("display", "none");

globalSocket = null;

}

function funcWSMessage(e) {

//console.log("funcWSMessage(): e.data = ", e.data);

var dataObj = JSON.parse(e.data);

if (dataObj['ret'] == "data") {

$("#cmd_result").append(dataObj['message'] + "<br>");

} else if (dataObj['ret'] == "finish") {

console.log("funcWSMessage(): ", dataObj['description'])

$("#cmd_result").append("<br>Websocket: " + dataObj['description'] + "<br>");

globalSocket.close(3009)

} else if (dataObj['ret'] == "error") {

console.log("funcWSMessage(): ", dataObj['description']);

$("#cmd_result").append("<br>Websocket: " + dataObj['description'] + "<br>");

} else {

$("#cmd_result").append("<br>Websocket: Invalid data format<br>");

}

</script>

</body>

</html>

2) 添加 src/main/java/com/example/controller/IndexController.java

package com.example.controller;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.ui.ModelMap;

@Controller

@RequestMapping("/")

public class IndexController {

@RequestMapping(method = RequestMethod.GET)

public String home(ModelMap modelMap) {

modelMap.addAttribute("message", "Springmvc Websocket Demo");

return "home";

}

3) 删除 src/main/webapp/index.jsp

10. 运行

参考第 3 步

2022-02-10 Springmvc+Websocket实现Web方式执行系统命令和结果显示

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