基于SpringBoot的代码在线运行的简单实现

说明

由于没有实现沙盒，所以这个运行只适合提交自己写的代码到服务器，不适合像 菜鸟工具 那样可以让人公开提交代码并访问。

基本思路

前端提交代码，后端运行并返回结果。

后端实现

为了方便实现后端采用到了SpringBoot

我们需要先完成代码运行所需要的配置

@ConfigurationProperties(prefix = "run.script")
@Component
public class Config {
    private String cpp;
    private String c;
    private String python;

    public void setCpp(String cpp) {
        this.cpp = cpp;
    }

    public void setC(String c) {
        this.c = c;
    }

    public void setPython(String python) {
        this.python = python;
    }

    public String getCpp() {
        return cpp;
    }

    public String getC() {
        return c;
    }

    public String getPython() {
        return python;
    }

}

配置yml文件

此处的cpp和c应为需要编译运行，所以需要根据不同的操作系统写运行脚本

所有的路径都必须是绝对路径

run:
  script:
    cpp: F:\Spring\runCode\src\main\resources\runCpp.bat
    c: F:\Spring\runCode\src\main\resources\runC.bat
    python: C:\Users\puzhiwei\AppData\Local\Programs\Python\Python38\python.exe

然后我们需要将前端提交的代码保存到文件

        // 获取系统缓存文件的位置
        String tmpDir = System.getProperty("java.io.tmpdir");
        // 随机文件夹的名字
        File pwd = Paths.get(tmpDir, String.format("%016x", nextLong.incrementAndGet())).toFile();
        // 新建文件夹
        pwd.mkdirs();
        ProcessBuilder pb = null;
        switch (type) {
            case "C":
                try (Writer writer = new BufferedWriter(new FileWriter(new File(pwd, "Main.c"), Charset.defaultCharset()))) {
                    writer.write(code);
                }
                pb = new ProcessBuilder().command(config.getC()).directory(pwd);
                break;
            case "CPP":
                try (Writer writer = new BufferedWriter(new FileWriter(new File(pwd, "Main.cpp"), Charset.defaultCharset()))) {
                    writer.write(code);
                }
                pb = new ProcessBuilder().command(config.getCpp()).directory(pwd);
                break;
            case "JAVA":
                try (Writer writer = new BufferedWriter(new FileWriter(new File(pwd, "Main.java"), Charset.defaultCharset()))) {
                    writer.write(code);
                }
                String[] command = new String[]{getJavaExecutePath(), "-Dfile.encoding=" + Charset.defaultCharset(), "--source", "11", "--enable-preview", "Main.java"};
                pb = new ProcessBuilder().command(command).directory(pwd);
                break;
            case "PYTHON":
                try (Writer writer = new BufferedWriter(new FileWriter(new File(pwd, "Main.py"), Charset.defaultCharset()))) {
                    writer.write(code);
                }
                pb = new ProcessBuilder().command(config.getPython(), "Main.py").directory(pwd);
                break;
            default:
                break;
        }

这段代码主要实现了将代码保存到系统的缓存文件夹中，

pb为要在终端中执行的编译运行命令

由于C和C++需要编译才能执行，所以执行的是运行脚本，需要根据自己的系统进行修改

在windows下如下

@echo off
clang -std=c11 main.c && a.exe

@echo off
clang++ -std=c++17 main.cpp && a.exe

获取 Java 执行路径的的代码如下

    private String getJavaExecutePath() {
        if (javaExec == null) {
            String javaHome = System.getProperty("java.home");
            String os = System.getProperty("os.name");
            boolean isWindows = os.toLowerCase().startsWith("windows");
            Path javaPath = Paths.get(javaHome, "bin", isWindows ? "java.exe" : "java");
            javaExec = javaPath.toString();
        }
        return javaExec;
    }

之后就是使用 ProcessBuilder 执行脚本，并读取运行结果了

pb.redirectErrorStream(true);
        Process p = pb.start();
        if (p.waitFor(5, TimeUnit.SECONDS)) {
            String result = null;
            try (InputStream input = p.getInputStream()) {
                result = readAsString(input, Charset.defaultCharset());
            }
            return new ProcessResult(p.exitValue(), result);
        } else {
            System.err.println(String.format("Error: process %s timeout. destroy forcibly.", p.pid()));
            p.destroyForcibly();
            return new ProcessResult(p.exitValue(), "运行超时");
        }

最后，这个类的完整代码如下

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.io.*;
import java.nio.charset.Charset;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;

/**
 * @author Pu Zhiwei {@literal puzhiweipuzhiwei@foxmail.com}
 * create          2020-03-13 18:22
 */
@Component
public class RunCode {
    private final Config config;

    private static String javaExec = null;


    private static AtomicLong nextLong = new AtomicLong(System.currentTimeMillis());

    @Autowired
    public RunCode(Config config) {
        this.config = config;
    }


    public ProcessResult runCode(String type, String code) throws IOException, InterruptedException {
        // 获取系统缓存文件的位置
        String tmpDir = System.getProperty("java.io.tmpdir");
        // 随机文件夹的名字
        File pwd = Paths.get(tmpDir, String.format("%016x", nextLong.incrementAndGet())).toFile();
        // 新建文件夹
        pwd.mkdirs();
        ProcessBuilder pb = null;
        switch (type) {
            case "C":
                try (Writer writer = new BufferedWriter(new FileWriter(new File(pwd, "Main.c"), Charset.defaultCharset()))) {
                    writer.write(code);
                }
                pb = new ProcessBuilder().command(config.getC()).directory(pwd);
                break;
            case "CPP":
                try (Writer writer = new BufferedWriter(new FileWriter(new File(pwd, "Main.cpp"), Charset.defaultCharset()))) {
                    writer.write(code);
                }
                pb = new ProcessBuilder().command(config.getCpp()).directory(pwd);
                break;
            case "JAVA":
                try (Writer writer = new BufferedWriter(new FileWriter(new File(pwd, "Main.java"), Charset.defaultCharset()))) {
                    writer.write(code);
                }
                String[] command = new String[]{getJavaExecutePath(), "-Dfile.encoding=" + Charset.defaultCharset(), "--source", "11", "--enable-preview", "Main.java"};
                pb = new ProcessBuilder().command(command).directory(pwd);
                break;
            case "PYTHON":
                try (Writer writer = new BufferedWriter(new FileWriter(new File(pwd, "Main.py"), Charset.defaultCharset()))) {
                    writer.write(code);
                }
                pb = new ProcessBuilder().command(config.getPython(), "Main.py").directory(pwd);
                break;
            default:
                break;
        }


        pb.redirectErrorStream(true);
        Process p = pb.start();
        if (p.waitFor(5, TimeUnit.SECONDS)) {
            String result = null;
            try (InputStream input = p.getInputStream()) {
                result = readAsString(input, Charset.defaultCharset());
            }
            return new ProcessResult(p.exitValue(), result);
        } else {
            System.err.println(String.format("Error: process %s timeout. destroy forcibly.", p.pid()));
            p.destroyForcibly();
            return new ProcessResult(p.exitValue(), "运行超时");
        }
    }



    private String getJavaExecutePath() {
        if (javaExec == null) {
            String javaHome = System.getProperty("java.home");
            String os = System.getProperty("os.name");
            boolean isWindows = os.toLowerCase().startsWith("windows");
            Path javaPath = Paths.get(javaHome, "bin", isWindows ? "java.exe" : "java");
            javaExec = javaPath.toString();
        }
        return javaExec;
    }

    public String readAsString(InputStream input, Charset charset) throws IOException {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        byte[] buffer = new byte[102400];
        for (; ; ) {
            int n = input.read(buffer);
            if (n == (-1)) {
                break;
            }
            output.write(buffer, 0, n);
        }
        return output.toString(charset);
    }
}

完整代码

写完这些，我们就基本完成了代码在后端的运行并返回结果

接下来可以写一个测试方法测试一下结果的运行

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class RunApplicationTests {

    @Autowired
    private RunCode runCode;

    @Test
    void contextLoads() throws Exception {
        String code = "#include <stdio.h>\n" +
                "\n" +
                "int main()\n" +
                "{\n" +
                "   printf(\"Hello, World! \\n\");\n" +
                "   \n" +
                "   return 0;\n" +
                "}";
        System.out.println(runCode.runCode("C", code).getOutput());
    }

}

测试运行

如果没有异常，应该可以看到如下内容

最后，写一个controller，用来接收前端提交的代码

@RestController
@CrossOrigin("*")
public class WebController {
    public final RunCode runCode;

    @Autowired
    public WebController(RunCode runCode) {
        this.runCode = runCode;
    }

    @PostMapping("/run")
    public ProcessResult runCode(@RequestBody CodeModel codeModel) throws Exception {
        return runCode.runCode(codeModel.getType(), codeModel.getCode());
    }
}

public class CodeModel {
    private String type;
    private String code;

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }
}

CodeModel 

/**
 * @author Pu Zhiwei {@literal puzhiweipuzhiwei@foxmail.com}
 * create          2020-03-13 18:26
 */
public class ProcessResult {
    private int exitCode;

    private String output;

    public ProcessResult(int exitCode, String output) {
        this.exitCode = exitCode;
        this.output = output;
    }

    public int getExitCode() {
        return exitCode;
    }

    public String getOutput() {
        return output;
    }
}

ProcessResult 

至此，我们的后端就基本完成了。

前端

我们先写一个简单的html页面来进行测试

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<select>
    <option selected>Java</option>
    <option>C</option>
</select>
<br/>
<textarea id="code"></textarea>
<button id="sub-btn" onclick="submit()">提交</button>
<br/>
<textarea id="output"></textarea>

<script>
    function submit() {
        let data = document.querySelector("#code").value;

        fetch("http://127.0.0.1:8848/run", {
            method: "POST",
            headers: {
                "Content-Type": "application/json; charset=UTF-8"
            },
            body: JSON.stringify({
                code: data,
                type: "JAVA"
            })

        }).then(response => response.json())
            .then(json => {
                console.log(json)
                document.querySelector("#output").value = json.output;
            });
    }
</script>
</body>
</html>

如果没有问题，我们就能看到如下结果了

最后，完善一下页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>代码在线运行工具</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.4.1/dist/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
    <style>
        #editor {
            position: absolute;
            width: 100%;
            height: 100%;
        }
    </style>
</head>
<body>
<nav>
    <div>
        <a href="/">代码在线运行工具</a>
        <button type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
            <span></span>
        </button>
    </div>
</nav>
<div></div>
<div>
    <div>
        <div>
            <div>
                <button id="sub-btn" onclick="submit()">点击运行！</button>
            </div>
            <div>
                <select onchange="selectLanguage(this)" id="language-type">
                    <option selected>Java</option>
                    <option>C</option>
                    <option>CPP</option>
                    <option>Python</option>
                </select>
            </div>
            <div>
                <button type="button" onclick="clean()">清空</button>
            </div>
        </div>
    </div>
    <div></div>

    <div>
        <div>
            <div id="editor"></div>
        </div>
        <div></div>
        <div>
            <textarea id="output" rows="15"></textarea>
        </div>
    </div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/ace/1.4.8/ace.js" type="text/javascript"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/ace/1.4.8/ext-language_tools.min.js" type="text/javascript"></script>
<!--<script src="https://cdnjs.cloudflare.com/ajax/libs/ace/1.4.8/mode-java.min.js" type="text/javascript"></script>-->
<script>
    ace.require("ace/ext/language_tools");
    const editor = ace.edit("editor");
    editor.session.setMode("ace/mode/java");
    editor.setTheme("ace/theme/github");
    // enable autocompletion and snippets
    editor.setOptions({
        enableBasicAutocompletion: true,
        enableSnippets: true,
        enableLiveAutocompletion: true
    });

    function submit() {
        document.querySelector("#output").value = "代码运行中！";
        let data = editor.getValue();


        fetch("http://127.0.0.1:8848/run", {
            method: "POST",
            headers: {
                "Content-Type": "application/json; charset=UTF-8"
            },
            body: JSON.stringify({
                code: data,
                type: document.querySelector("#language-type").value.toUpperCase()
            })

        }).then(response => response.json())
            .then(json => {
                console.log(json)
                document.querySelector("#output").value = json.output;
            });
    }

    function clean() {
        editor.setValue("");
    }

    function selectLanguage(e) {
        let mode = "ace/mode/" + e.value.toLowerCase();
        if (e.value.toLowerCase() === "c" || e.value.toLowerCase() === "cpp") {
            mode = "ace/mode/c_cpp"
        }
        editor.session.setMode(mode);
    }
</script>
</body>
</html>

效果如下