OJ在线评测系统代码沙箱优化模版方法模式使用与有规范的流程并且执行流程可以复用

代码沙箱优化模版方法模式

上次我们代码沙箱的docker实现和原生实现

我们可以使用模版方法设计模式去优化我们的代码

我们原生的java实现代码沙箱和docker实现代码沙箱是有更多重复点的

比如说把文件收集文件进行校验

我们要用模版方法设计模式

定义一套通用的执行流程让子类去负责每个具体步骤的执行流程

模版方法的应用场景使用与有规范的流程并且执行流程可以复用

作用是答复节约重复代码量便于项目扩展更好的去维护

抽象出具体的流程

先复制具体的实现类

再把代码从完整的方法抽离成一个一个的子写法

想把代码保存为文件


    /**
     * 1. 把用户的代码保存为文件
     * @param code 用户代码
     * @return
     */
    public File saveCodeToFile(String code) {
        String userDir = System.getProperty("user.dir");
        String globalCodePathName = userDir + File.separator + GLOBAL_CODE_DIR_NAME;
        // 判断全局代码目录是否存在，没有则新建
        if (!FileUtil.exist(globalCodePathName)) {
            FileUtil.mkdir(globalCodePathName);
        }

        // 把用户的代码隔离存放
        String userCodeParentPath = globalCodePathName + File.separator + UUID.randomUUID();
        String userCodePath = userCodeParentPath + File.separator + GLOBAL_JAVA_CLASS_NAME;
        File userCodeFile = FileUtil.writeString(code, userCodePath, StandardCharsets.UTF_8);
        return userCodeFile;
    }

想编译代码获得class文件

   
   	/**
     * 2、编译代码
     * @param userCodeFile
     * @return
     */
    public ExecuteMessage compileFile(File userCodeFile) {
        String compileCmd = String.format("javac -encoding utf-8 %s", userCodeFile.getAbsolutePath());
        try {
            Process compileProcess = Runtime.getRuntime().exec(compileCmd);
            ExecuteMessage executeMessage = ProcessUtils.runProcessAndGetMessage(compileProcess, "编译");
            if (executeMessage.getExitValue() != 0) {
                throw new RuntimeException("编译错误");
            }
            return executeMessage;
        } catch (Exception e) {
//            return getErrorResponse(e);
            throw new RuntimeException(e);
        }
    }

执行文件，获得执行结果列表

    /**
     * 3、执行文件，获得执行结果列表
     * @param userCodeFile
     * @param inputList
     * @return
     */
    public List<ExecuteMessage> runFile(File userCodeFile, List<String> inputList) {
        String userCodeParentPath = userCodeFile.getParentFile().getAbsolutePath();

        List<ExecuteMessage> executeMessageList = new ArrayList<>();
        for (String inputArgs : inputList) {
//            String runCmd = String.format("java -Xmx256m -Dfile.encoding=UTF-8 -cp %s Main %s", userCodeParentPath, inputArgs);
            String runCmd = String.format("java -Xmx256m -Dfile.encoding=UTF-8 -cp %s Main %s", userCodeParentPath, inputArgs);
            try {
                Process runProcess = Runtime.getRuntime().exec(runCmd);
                // 超时控制
                new Thread(() -> {
                    try {
                        Thread.sleep(TIME_OUT);
                        System.out.println("超时了，中断");
                        runProcess.destroy();
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                }).start();
                ExecuteMessage executeMessage = ProcessUtils.runProcessAndGetMessage(runProcess, "运行");
                System.out.println(executeMessage);
                executeMessageList.add(executeMessage);
            } catch (Exception e) {
                throw new RuntimeException("执行错误", e);
            }
        }
        return executeMessageList;
    }

获取输出结果

   /**
     * 4、获取输出结果
     * @param executeMessageList
     * @return
     */
    public ExecuteCodeResponse getOutputResponse(List<ExecuteMessage> executeMessageList) {
        ExecuteCodeResponse executeCodeResponse = new ExecuteCodeResponse();
        List<String> outputList = new ArrayList<>();
        // 取用时最大值，便于判断是否超时
        long maxTime = 0;
        for (ExecuteMessage executeMessage : executeMessageList) {
            String errorMessage = executeMessage.getErrorMessage();
            if (StrUtil.isNotBlank(errorMessage)) {
                executeCodeResponse.setMessage(errorMessage);
                // 用户提交的代码执行中存在错误
                executeCodeResponse.setStatus(3);
                break;
            }
            outputList.add(executeMessage.getMessage());
            Long time = executeMessage.getTime();
            if (time != null) {
                maxTime = Math.max(maxTime, time);
            }
        }
        // 正常运行完成
        if (outputList.size() == executeMessageList.size()) {
            executeCodeResponse.setStatus(1);
        }
        executeCodeResponse.setOutputList(outputList);
        JudgeInfo judgeInfo = new JudgeInfo();
        judgeInfo.setTime(maxTime);
        // 要借助第三方库来获取内存占用，非常麻烦，此处不做实现
//        judgeInfo.setMemory();
        executeCodeResponse.setJudgeInfo(judgeInfo);
        return executeCodeResponse;
    }

删除文件

 /**
     * 5、删除文件
     * @param userCodeFile
     * @return
     */
    public boolean deleteFile(File userCodeFile) {
        if (userCodeFile.getParentFile() != null) {
            String userCodeParentPath = userCodeFile.getParentFile().getAbsolutePath();
            boolean del = FileUtil.del(userCodeParentPath);
            System.out.println("删除" + (del ? "成功" : "失败"));
            return del;
        }
        return true;
    }

获取错误响应

    /**
     * 6、获取错误响应
     *
     * @param e
     * @return
     */
    private ExecuteCodeResponse getErrorResponse(Throwable e) {
        ExecuteCodeResponse executeCodeResponse = new ExecuteCodeResponse();
        executeCodeResponse.setOutputList(new ArrayList<>());
        executeCodeResponse.setMessage(e.getMessage());
        // 表示代码沙箱错误
        executeCodeResponse.setStatus(2);
        executeCodeResponse.setJudgeInfo(new JudgeInfo());
        return executeCodeResponse;
    }

我们之前流程化程序

这样提成一一个方法就会很简单

自上而下一层一层去抽取

我们此时重写父类中的方法

  @Override
    public ExecuteCodeResponse executeCode(ExecuteCodeRequest executeCodeRequest) {
        List<String> inputList = executeCodeRequest.getInputList();
        String code = executeCodeRequest.getCode();
        String language = executeCodeRequest.getLanguage();

//        1. 把用户的代码保存为文件
        File userCodeFile = saveCodeToFile(code);

//        2. 编译代码，得到 class 文件
        ExecuteMessage compileFileExecuteMessage = compileFile(userCodeFile);
        System.out.println(compileFileExecuteMessage);

        // 3. 执行代码，得到输出结果
        List<ExecuteMessage> executeMessageList = runFile(userCodeFile, inputList);

//        4. 收集整理输出结果
        ExecuteCodeResponse outputResponse = getOutputResponse(executeMessageList);

//        5. 文件清理
        boolean b = deleteFile(userCodeFile);
        if (!b) {
            log.error("deleteFile error, userCodeFilePath = {}", userCodeFile.getAbsolutePath());
        }
        return outputResponse;
    }

现在我们就能定义子类

直接复用父类的模版方法就行

这就是模版方法设计模式 Template

package com.yupi.yuojcodesandbox;

import com.yupi.yuojcodesandbox.model.ExecuteCodeRequest;
import com.yupi.yuojcodesandbox.model.ExecuteCodeResponse;
import org.springframework.stereotype.Component;

/**
 * Java 原生代码沙箱实现（直接复用模板方法）
 */
@Component
public class JavaNativeCodeSandbox extends JavaCodeSandboxTemplate {

    @Override
    public ExecuteCodeResponse executeCode(ExecuteCodeRequest executeCodeRequest) {
        return super.executeCode(executeCodeRequest);
    }
}

我们这边如果在子类里面重写了父类的某个方法

那么子类执行的时候

优先的是去执行子类里面重写方法就是已经覆盖过的实现

如果没有重写是去执行模版中的默认实现

接下来我们要去改造一下docker代码沙箱的实现

继承我们的模版方法

自定义某些方法的实现

我们发现我们写JavaDockerCodeSandbox类就是重写了创建容器类

package com.yupi.yuojcodesandbox;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.StrUtil;
import com.yupi.yuojcodesandbox.model.ExecuteCodeRequest;
import com.yupi.yuojcodesandbox.model.ExecuteCodeResponse;
import com.yupi.yuojcodesandbox.model.ExecuteMessage;
import com.yupi.yuojcodesandbox.model.JudgeInfo;
import com.yupi.yuojcodesandbox.utils.ProcessUtils;
import lombok.extern.slf4j.Slf4j;

import java.io.File;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

/**
 * Java 代码沙箱模板方法的实现
 */
@Slf4j
public abstract class JavaCodeSandboxTemplate implements CodeSandbox {

    private static final String GLOBAL_CODE_DIR_NAME = "tmpCode";

    private static final String GLOBAL_JAVA_CLASS_NAME = "Main.java";

    private static final long TIME_OUT = 5000L;

    /**
     *
     * @param executeCodeRequest 代码请求
     * @return
     */
    @Override
    public ExecuteCodeResponse executeCode(ExecuteCodeRequest executeCodeRequest) {
        List<String> inputList = executeCodeRequest.getInputList();
        String code = executeCodeRequest.getCode();
        String language = executeCodeRequest.getLanguage();

//        1. 把用户的代码保存为文件
        File userCodeFile = saveCodeToFile(code);

//        2. 编译代码，得到 class 文件
        ExecuteMessage compileFileExecuteMessage = compileFile(userCodeFile);
        System.out.println(compileFileExecuteMessage);

        // 3. 执行代码，得到输出结果
        List<ExecuteMessage> executeMessageList = runFile(userCodeFile, inputList);

//        4. 收集整理输出结果
        ExecuteCodeResponse outputResponse = getOutputResponse(executeMessageList);

//        5. 文件清理
        boolean b = deleteFile(userCodeFile);
        if (!b) {
            log.error("deleteFile error, userCodeFilePath = {}", userCodeFile.getAbsolutePath());
        }
        return outputResponse;
    }


    /**
     * 1. 把用户的代码保存为文件
     * @param code 用户代码
     * @return
     */
    public File saveCodeToFile(String code) {
        String userDir = System.getProperty("user.dir");
        String globalCodePathName = userDir + File.separator + GLOBAL_CODE_DIR_NAME;
        // 判断全局代码目录是否存在，没有则新建
        if (!FileUtil.exist(globalCodePathName)) {
            FileUtil.mkdir(globalCodePathName);
        }

        // 把用户的代码隔离存放
        String userCodeParentPath = globalCodePathName + File.separator + UUID.randomUUID();
        String userCodePath = userCodeParentPath + File.separator + GLOBAL_JAVA_CLASS_NAME;
        File userCodeFile = FileUtil.writeString(code, userCodePath, StandardCharsets.UTF_8);
        return userCodeFile;
    }

    /**
     * 2、编译代码
     * @param userCodeFile 保存的文件
     * @return
     */
    public ExecuteMessage compileFile(File userCodeFile) {
        String compileCmd = String.format("javac -encoding utf-8 %s", userCodeFile.getAbsolutePath());
        try {
            Process compileProcess = Runtime.getRuntime().exec(compileCmd);
            ExecuteMessage executeMessage = ProcessUtils.runProcessAndGetMessage(compileProcess, "编译");
            if (executeMessage.getExitValue() != 0) {
                throw new RuntimeException("编译错误");
            }
            return executeMessage;
        } catch (Exception e) {
//            return getErrorResponse(e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 3、执行文件，获得执行结果列表
     * @param userCodeFile
     * @param inputList
     * @return
     */
    public List<ExecuteMessage> runFile(File userCodeFile, List<String> inputList) {
        String userCodeParentPath = userCodeFile.getParentFile().getAbsolutePath();

        List<ExecuteMessage> executeMessageList = new ArrayList<>();
        for (String inputArgs : inputList) {
//            String runCmd = String.format("java -Xmx256m -Dfile.encoding=UTF-8 -cp %s Main %s", userCodeParentPath, inputArgs);
            String runCmd = String.format("java -Xmx256m -Dfile.encoding=UTF-8 -cp %s Main %s", userCodeParentPath, inputArgs);
            try {
                Process runProcess = Runtime.getRuntime().exec(runCmd);
                // 超时控制
                new Thread(() -> {
                    try {
                        Thread.sleep(TIME_OUT);
                        System.out.println("超时了，中断");
                        runProcess.destroy();
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                }).start();
                ExecuteMessage executeMessage = ProcessUtils.runProcessAndGetMessage(runProcess, "运行");
                System.out.println(executeMessage);
                executeMessageList.add(executeMessage);
            } catch (Exception e) {
                throw new RuntimeException("执行错误", e);
            }
        }
        return executeMessageList;
    }

    /**
     * 4、获取输出结果
     * @param executeMessageList
     * @return
     */
    public ExecuteCodeResponse getOutputResponse(List<ExecuteMessage> executeMessageList) {
        ExecuteCodeResponse executeCodeResponse = new ExecuteCodeResponse();
        List<String> outputList = new ArrayList<>();
        // 取用时最大值，便于判断是否超时
        long maxTime = 0;
        for (ExecuteMessage executeMessage : executeMessageList) {
            String errorMessage = executeMessage.getErrorMessage();
            if (StrUtil.isNotBlank(errorMessage)) {
                executeCodeResponse.setMessage(errorMessage);
                // 用户提交的代码执行中存在错误
                executeCodeResponse.setStatus(3);
                break;
            }
            outputList.add(executeMessage.getMessage());
            Long time = executeMessage.getTime();
            if (time != null) {
                maxTime = Math.max(maxTime, time);
            }
        }
        // 正常运行完成
        if (outputList.size() == executeMessageList.size()) {
            executeCodeResponse.setStatus(1);
        }
        executeCodeResponse.setOutputList(outputList);
        JudgeInfo judgeInfo = new JudgeInfo();
        judgeInfo.setTime(maxTime);
        // 要借助第三方库来获取内存占用，非常麻烦，此处不做实现
//        judgeInfo.setMemory();
        executeCodeResponse.setJudgeInfo(judgeInfo);
        return executeCodeResponse;
    }

    /**
     * 5、删除文件
     * @param userCodeFile
     * @return
     */
    public boolean deleteFile(File userCodeFile) {
        if (userCodeFile.getParentFile() != null) {
            String userCodeParentPath = userCodeFile.getParentFile().getAbsolutePath();
            boolean del = FileUtil.del(userCodeParentPath);
            System.out.println("删除" + (del ? "成功" : "失败"));
            return del;
        }
        return true;
    }

    /**
     * 6、获取错误响应
     *
     * @param e
     * @return
     */
    private ExecuteCodeResponse getErrorResponse(Throwable e) {
        ExecuteCodeResponse executeCodeResponse = new ExecuteCodeResponse();
        executeCodeResponse.setOutputList(new ArrayList<>());
        executeCodeResponse.setMessage(e.getMessage());
        // 表示代码沙箱错误
        executeCodeResponse.setStatus(2);
        executeCodeResponse.setJudgeInfo(new JudgeInfo());
        return executeCodeResponse;
    }
}

熟悉模版方法模式的人一看就懂这个方法

package com.yupi.yuojcodesandbox;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.StrUtil;
import com.yupi.yuojcodesandbox.model.ExecuteCodeRequest;
import com.yupi.yuojcodesandbox.model.ExecuteCodeResponse;
import com.yupi.yuojcodesandbox.model.ExecuteMessage;
import com.yupi.yuojcodesandbox.model.JudgeInfo;
import com.yupi.yuojcodesandbox.utils.ProcessUtils;
import lombok.extern.slf4j.Slf4j;

import java.io.File;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

/**
 * Java 代码沙箱模板方法的实现
 */
@Slf4j
public abstract class JavaCodeSandboxTemplate implements CodeSandbox {

    private static final String GLOBAL_CODE_DIR_NAME = "tmpCode";

    private static final String GLOBAL_JAVA_CLASS_NAME = "Main.java";

    private static final long TIME_OUT = 5000L;

    /**
     *
     * @param executeCodeRequest 代码请求
     * @return
     */
    @Override
    public ExecuteCodeResponse executeCode(ExecuteCodeRequest executeCodeRequest) {
        List<String> inputList = executeCodeRequest.getInputList();
        String code = executeCodeRequest.getCode();
        String language = executeCodeRequest.getLanguage();

//        1. 把用户的代码保存为文件
        File userCodeFile = saveCodeToFile(code);

//        2. 编译代码，得到 class 文件
        ExecuteMessage compileFileExecuteMessage = compileFile(userCodeFile);
        System.out.println(compileFileExecuteMessage);

        // 3. 执行代码，得到输出结果
        List<ExecuteMessage> executeMessageList = runFile(userCodeFile, inputList);

//        4. 收集整理输出结果
        ExecuteCodeResponse outputResponse = getOutputResponse(executeMessageList);

//        5. 文件清理
        boolean b = deleteFile(userCodeFile);
        if (!b) {
            log.error("deleteFile error, userCodeFilePath = {}", userCodeFile.getAbsolutePath());
        }
        return outputResponse;
    }


    /**
     * 1. 把用户的代码保存为文件
     * @param code 用户代码
     * @return
     */
    public File saveCodeToFile(String code) {
        String userDir = System.getProperty("user.dir");
        String globalCodePathName = userDir + File.separator + GLOBAL_CODE_DIR_NAME;
        // 判断全局代码目录是否存在，没有则新建
        if (!FileUtil.exist(globalCodePathName)) {
            FileUtil.mkdir(globalCodePathName);
        }

        // 把用户的代码隔离存放
        String userCodeParentPath = globalCodePathName + File.separator + UUID.randomUUID();
        String userCodePath = userCodeParentPath + File.separator + GLOBAL_JAVA_CLASS_NAME;
        File userCodeFile = FileUtil.writeString(code, userCodePath, StandardCharsets.UTF_8);
        return userCodeFile;
    }

    /**
     * 2、编译代码
     * @param userCodeFile 保存的文件
     * @return
     */
    public ExecuteMessage compileFile(File userCodeFile) {
        String compileCmd = String.format("javac -encoding utf-8 %s", userCodeFile.getAbsolutePath());
        try {
            Process compileProcess = Runtime.getRuntime().exec(compileCmd);
            ExecuteMessage executeMessage = ProcessUtils.runProcessAndGetMessage(compileProcess, "编译");
            if (executeMessage.getExitValue() != 0) {
                throw new RuntimeException("编译错误");
            }
            return executeMessage;
        } catch (Exception e) {
//            return getErrorResponse(e);
            throw new RuntimeException(e);
        }
    }

    /**
     * 3、执行文件，获得执行结果列表
     * @param userCodeFile
     * @param inputList
     * @return
     */
    public List<ExecuteMessage> runFile(File userCodeFile, List<String> inputList) {
        String userCodeParentPath = userCodeFile.getParentFile().getAbsolutePath();

        List<ExecuteMessage> executeMessageList = new ArrayList<>();
        for (String inputArgs : inputList) {
//            String runCmd = String.format("java -Xmx256m -Dfile.encoding=UTF-8 -cp %s Main %s", userCodeParentPath, inputArgs);
            String runCmd = String.format("java -Xmx256m -Dfile.encoding=UTF-8 -cp %s Main %s", userCodeParentPath, inputArgs);
            try {
                Process runProcess = Runtime.getRuntime().exec(runCmd);
                // 超时控制
                new Thread(() -> {
                    try {
                        Thread.sleep(TIME_OUT);
                        System.out.println("超时了，中断");
                        runProcess.destroy();
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                }).start();
                ExecuteMessage executeMessage = ProcessUtils.runProcessAndGetMessage(runProcess, "运行");
                System.out.println(executeMessage);
                executeMessageList.add(executeMessage);
            } catch (Exception e) {
                throw new RuntimeException("执行错误", e);
            }
        }
        return executeMessageList;
    }

    /**
     * 4、获取输出结果
     * @param executeMessageList
     * @return
     */
    public ExecuteCodeResponse getOutputResponse(List<ExecuteMessage> executeMessageList) {
        ExecuteCodeResponse executeCodeResponse = new ExecuteCodeResponse();
        List<String> outputList = new ArrayList<>();
        // 取用时最大值，便于判断是否超时
        long maxTime = 0;
        for (ExecuteMessage executeMessage : executeMessageList) {
            String errorMessage = executeMessage.getErrorMessage();
            if (StrUtil.isNotBlank(errorMessage)) {
                executeCodeResponse.setMessage(errorMessage);
                // 用户提交的代码执行中存在错误
                executeCodeResponse.setStatus(3);
                break;
            }
            outputList.add(executeMessage.getMessage());
            Long time = executeMessage.getTime();
            if (time != null) {
                maxTime = Math.max(maxTime, time);
            }
        }
        // 正常运行完成
        if (outputList.size() == executeMessageList.size()) {
            executeCodeResponse.setStatus(1);
        }
        executeCodeResponse.setOutputList(outputList);
        JudgeInfo judgeInfo = new JudgeInfo();
        judgeInfo.setTime(maxTime);
        // 要借助第三方库来获取内存占用，非常麻烦，此处不做实现
//        judgeInfo.setMemory();
        executeCodeResponse.setJudgeInfo(judgeInfo);
        return executeCodeResponse;
    }

    /**
     * 5、删除文件
     * @param userCodeFile
     * @return
     */
    public boolean deleteFile(File userCodeFile) {
        if (userCodeFile.getParentFile() != null) {
            String userCodeParentPath = userCodeFile.getParentFile().getAbsolutePath();
            boolean del = FileUtil.del(userCodeParentPath);
            System.out.println("删除" + (del ? "成功" : "失败"));
            return del;
        }
        return true;
    }

    /**
     * 6、获取错误响应
     *
     * @param e
     * @return
     */
    private ExecuteCodeResponse getErrorResponse(Throwable e) {
        ExecuteCodeResponse executeCodeResponse = new ExecuteCodeResponse();
        executeCodeResponse.setOutputList(new ArrayList<>());
        executeCodeResponse.setMessage(e.getMessage());
        // 表示代码沙箱错误
        executeCodeResponse.setStatus(2);
        executeCodeResponse.setJudgeInfo(new JudgeInfo());
        return executeCodeResponse;
    }
}