title: "[CodeSnippet] - A Simple Judger for Java" tags:
一个简单判题机，基于Java语言，于Windows或Linux平台，为了本地测试。
易于使用的接口设计
规格化的信息格式
链式配置函数
输入/输出文件模糊扫描
支持ForEach的迭代器模式
自动案例计时
自动重定向IO
自动异常捕获
设置单案例运行时间限制
全局判题结果统计
可选的手动计时器控制
可选的忽略输入和输出
可选的输入输出行数限制
可自定义的错误流文件
输出Judger调试信息
跳过特定案例
忽略/不忽略特定案例
延迟初始化
优雅退出
内建输出函数
安全运行块
package util;
import java.awt.*;
import java.io.*;
import java.net.URI;
import java.nio.file.Files;
import java.util.List;
import java.util.Queue;
import java.util.*;
import java.util.stream.Stream;
/**
* @author Teeth
* @date 3/5/2022 07:16
* A simple judger to read in the input and output files and compare them.
*/
@SuppressWarnings({"UnusedReturnValue", "SpellCheckingInspection"})
public class Judger implements Iterable<Scanner>, Iterator<Scanner> {
/* Pair Define */
@SuppressWarnings("unused")
public static class Pair<K, V> {
public K key;
public V value;
public Pair(K key, V value) {
this.key = key;
this.value = value;
}
public K getKey() {
return key;
}
public V getValue() {
return value;
}
public void setKey(K key) {
this.key = key;
}
public void setValue(V value) {
this.value = value;
}
}
/* Special Flags */
private static final String ignoreCaseFileNamePrefix = "_";
private static final int defaultEndTimestamp = 0xdead;
/* Redirect System.out */
private PrintStream tempOutPrintStream;
private File tempOutFile;
private Pair<File, File> currentCase;
/* Case Queue */
private boolean judgerInitialized = false;
private final File inDirectory;
private final File outDirectory;
private final Queue<Pair<File, File>> caseQueue = new LinkedList<>();
/* Judger Flags */
private final ArrayList<String> joinCaseFileKeywords = new ArrayList<>();
private final ArrayList<String> ignoreExceptCaseFileKeywords = new ArrayList<>();
private final ArrayList<String> ignoreCaseFileKeywords = new ArrayList<>();
private boolean skipCurrentCaseFlag = false;
private long timeLimitMS = Long.MAX_VALUE;
private boolean hideInputAndOutputFlag = false;
private boolean prettyFormat = false;
private int maxExpectInputLines = 0xbadc0de;
private int maxExpectOutputLines = 0xbadc0de;
private int maxYourOutputLines = 0xbadc0de;
private boolean debugPrintFunctions = true;
/* Statistics */
private StringBuilder resultStatistics = new StringBuilder();
private long startTimestamp;
private long endTimestamp;
/* Use this constructor if you don't know how to fill the paths */
public Judger(File inDirectory, File outDirectory) {
this.inDirectory = inDirectory;
this.outDirectory = outDirectory;
}
/* It's recommended to use this constructor. */
public Judger(String casePath) {
this(".", casePath);
}
public Judger(String basePath, String casePath) {
this(basePath, casePath, "TEST", "ANSWER");
}
public Judger(String basePath, String casePath, String inDirectoryName, String outDirectoryName) {
this.inDirectory = new File(basePath + File.separator + casePath + File.separator + inDirectoryName);
this.outDirectory = new File(basePath + File.separator + casePath + File.separator + outDirectoryName);
}
private String getInPath() {
return this.inDirectory.getAbsolutePath();
}
private String getOutPath() {
return this.outDirectory.getAbsolutePath();
}
private void initJudger() {
/* Init the exception handler */
registerJudgerUncaughtExceptionHandler();
/* Init file queue */
initFileQueue();
}
private void initFileQueue() {
try {
for (File file : new File(this.getInPath()).listFiles()) {
String entryName = file.getName();
/* Ignore Cases */
// Ignore Case File-Name-Prefix
if (entryName.startsWith(ignoreCaseFileNamePrefix) && this.joinCaseFileKeywords.stream().noneMatch(entryName::contains)) {
continue;
}
// Ignore Case File-Name-Keywords
if (this.ignoreExceptCaseFileKeywords.size() > 0) {
if (this.ignoreExceptCaseFileKeywords.stream().noneMatch(entryName::contains) && this.joinCaseFileKeywords.stream().noneMatch(entryName::contains)) {
continue;
}
}
if (this.ignoreCaseFileKeywords.stream().anyMatch(entryName::contains) && this.joinCaseFileKeywords.stream().noneMatch(entryName::contains))
continue;
entryName = entryName.substring(0, entryName.lastIndexOf("."));
File inEntity = new File(this.getInPath() + File.separator + entryName + ".in");
File outEntity = new File(this.getOutPath() + File.separator + entryName + ".out");
Pair<File, File> pair = new Pair<>(inEntity, outEntity);
this.caseQueue.add(pair);
}
} catch (Exception e) {
e.printStackTrace();
this.displayDebugInfo();
}
}
private Scanner redirectInput(Pair<File, File> pair) {
try {
return new Scanner(pair.getKey());
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return null;
}
private void redirectOutput() {
try {
this.tempOutFile = File.createTempFile("temp", ".out");
this.tempOutPrintStream = new PrintStream(new FileOutputStream(this.tempOutFile));
} catch (IOException e) {
e.printStackTrace();
}
System.setOut(this.tempOutPrintStream);
}
public Judger redirectError(String file) {
return this.redirectError(new File(file));
}
public Judger redirectError(File file) {
try {
System.setErr(new PrintStream(new FileOutputStream(file)));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return this;
}
/* This method assumes that the in-case and out-case have the same parent directory,
* and will write error file to the parent direcotry.
* */
public Judger redirectError() {
/* Get main() java file name */
StackTraceElement[] stackTrace = new Exception().getStackTrace();
String runningJavaFileName = stackTrace[stackTrace.length - 1].getFileName();
/* Redirect */
String errorFileName = runningJavaFileName + ".error";
this.redirectError(new File(this.inDirectory.getParent() + File.separator + errorFileName));
return this;
}
private void displayExpectationIO(Pair<File, File> pair) {
System.err.println("Current Case: " + pair.getKey().getName() + " & " + pair.getValue().getName());
/* Display Expectation IO */
if (this.hideInputAndOutputFlag) return;
try {
List<String> expectInput = Files.readAllLines(pair.getKey().toPath());
List<String> expectOutput = Files.readAllLines(pair.getValue().toPath());
// Limit Expect Input/Output
if (this.maxExpectInputLines < expectInput.size()) {
int omit = expectInput.size() - this.maxExpectInputLines;
expectInput = expectInput.subList(0, this.maxExpectInputLines);
this.addLimitedMessage(expectInput, omit);
}
if (this.maxYourOutputLines < expectOutput.size()) {
int omit = expectOutput.size() - this.maxExpectOutputLines;
expectOutput = expectOutput.subList(0, this.maxExpectOutputLines);
this.addLimitedMessage(expectOutput, omit);
}
System.err.println("Expected Input: " + expectInput);
System.err.println("Expected Output: " + expectOutput);
// Flush to make sure the message is displayed
System.err.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
private void displaySeparator() {
System.err.println("-----------------------------------------------------");
}
private void displayStatistics() {
this.displaySeparator();
System.err.println("Result Statistics: " + this.resultStatistics);
}
private long displayTimeCost() {
// If the timer didn't be stopped manually, stop it.
if (this.endTimestamp == defaultEndTimestamp) {
this.manuallyStopTimer();
}
// Calc the time cost.
long timeCost = this.endTimestamp - this.startTimestamp;
System.err.printf("Time Cost: %f ms (%d ns)%n", timeCost / 1E6, timeCost);
return timeCost;
}
@Override
public Iterator<Scanner> iterator() {
return this;
}
@Override
public boolean hasNext() {
/* Delay the initialization of judger */
if (!this.judgerInitialized) {
this.initJudger();
this.judgerInitialized = true;
// Special case: if no case files are valid (the case directory is empty or the case is filtered).
if (this.caseQueue.isEmpty()) {
System.err.println("No case files are valid.");
System.err.println("1. The case directory is empty.");
System.err.println("2. The case is filtered.");
return false;
}
}
/* All the cases processed ? */
if (this.caseQueue.isEmpty()) {
// Judge the last case.
this.judgeCase();
// Output the statistics.
this.displayStatistics();
return false;
}
return true;
}
@Override
public Scanner next() {
/* No more cases ? */
if (this.caseQueue.isEmpty()) throw new IllegalStateException("No more cases.");
/* Judge previous case ? */
if (this.currentCase != null) {
// Judge the previous case.
this.judgeCase();
}
/* Get a new case */
Pair<File, File> aCase = this.currentCase = this.caseQueue.poll();
this.displaySeparator();
this.displayExpectationIO(aCase);
this.redirectOutput();
Scanner scanner = this.redirectInput(aCase);
/* Start the timer */
this.manuallyStartTimer();
return scanner;
}
public Pair<File, File> getCurrentCase() {
return this.currentCase;
}
public String getCurrentCaseName() {
return this.currentCase.getKey().getName();
}
/**
* Call this function if you want to reset the timer.
*/
public void manuallyStartTimer() {
this.startTimestamp = System.nanoTime();
this.endTimestamp = defaultEndTimestamp;
}
public void manuallyStopTimer() {
this.endTimestamp = System.nanoTime();
}
public Judger displayDebugInfo() {
this.displaySeparator();
System.err.println("● Java Program Run Path = " + new File(".").getAbsolutePath());
try {
System.err.println("☆ InPath = " + this.getInPath());
System.err.println("☆ InPath (Absolute) = " + new File(this.getInPath()).getAbsolutePath());
System.err.println("★ InPath (Canonical) = " + new File(this.getInPath()).getCanonicalPath());
System.err.println("☆ OutPath = " + this.getOutPath());
System.err.println("☆ OutPath (Absolute) = " + new File(this.getOutPath()).getAbsolutePath());
System.err.println("★ OutPath (Canonical) = " + new File(this.getOutPath()).getCanonicalPath());
} catch (IOException e) {
e.printStackTrace();
}
this.displaySeparator();
return this;
}
public Judger hideInputAndOutput() {
this.hideInputAndOutputFlag = true;
return this;
}
public Judger setTimeLimitMS(long timeLimitMS) {
this.timeLimitMS = timeLimitMS;
return this;
}
public Judger setMaxExpectedInputLines(int limit) {
this.maxExpectInputLines = limit;
return this;
}
public Judger setMaxExpectedOutputLines(int limit) {
this.maxExpectOutputLines = limit;
return this;
}
public Judger setMaxYourOutputLines(int limit) {
this.maxYourOutputLines = limit;
return this;
}
public Judger enablePrettyFormat() {
this.prettyFormat = true;
return this;
}
public Judger disablePrettyFormat() {
this.prettyFormat = false;
return this;
}
public Judger enableDebugPrintFunctions() {
this.debugPrintFunctions = true;
return this;
}
public Judger disableDebugPrintFunctions() {
this.debugPrintFunctions = false;
return this;
}
private void addLimitedMessage(List<String> list, int omit) {
list.add(String.format("Omit the remaining %d line(s)...", omit));
}
private String prettyFormat(List<String> list) {
StringBuilder sb = new StringBuilder("\n");
sb.append("[SOF]");
for (int i = 0; i < list.size(); i++) {
sb.append(list.get(i));
if (i == list.size() - 1) {
sb.append("[EOF]");
} else sb.append("\n");
}
// Special case: empty list
if (list.isEmpty()) sb.append("[EOF]");
return sb.toString();
}
private String formatList(List<String> list) {
if (this.prettyFormat) {
return this.prettyFormat(list);
} else return list.toString();
}
/* Judger will set a skip flag, but you should manually skip your algorithm steps. */
public Judger skipCurrentCase() {
this.skipCurrentCaseFlag = true;
return this;
}
public Judger ignoreExceptCase(String keywords) {
this.ignoreExceptCaseFileKeywords.add(keywords);
return this;
}
public Judger ignoreCase(String keywords) {
this.ignoreCaseFileKeywords.add(keywords);
return this;
}
/* Join a case and guarantee the case will be added into cases queue */
public Judger joinCase(String keywords) {
this.joinCaseFileKeywords.add(keywords);
return this;
}
@SuppressWarnings("UnusedAssignment")
private void judgeCase() {
/* Read from the temp out file */
List<String> tempOutFileContent = null;
try {
tempOutFileContent = Files.readAllLines(this.tempOutFile.toPath());
if (!this.hideInputAndOutputFlag) {
if (this.maxYourOutputLines < tempOutFileContent.size()) {
int omit = tempOutFileContent.size() - this.maxYourOutputLines;
tempOutFileContent = tempOutFileContent.subList(0, this.maxYourOutputLines);
this.addLimitedMessage(tempOutFileContent, omit);
}
System.err.println("Your Output: " + formatList(tempOutFileContent));
}
} catch (IOException e) {
e.printStackTrace();
}
/* End the timer. */
// it's better to stop the timer earlier, but it's not necessary.
long timeCost = 0;
if (!this.skipCurrentCaseFlag) {
timeCost = this.displayTimeCost();
}
/* Judge Result Type */
List<String> expectedOutFileContent;
try {
/* Handle Judger Flags */
if (this.skipCurrentCaseFlag) {
this.skipCurrentCaseFlag = false;
this.resultStatistics.append("→ ");
System.err.println("Skipped.");
return;
}
/* Compare the texts */
expectedOutFileContent = Files.readAllLines(this.currentCase.getValue().toPath());
boolean accepted = true;
String message = "Accepted";
String symbol = "√";
// Your Output == Expect Output ?
if (!Boolean.logicalAnd(accepted, tempOutFileContent.toString().equals(expectedOutFileContent.toString()))) {
accepted = false;
message = "Wrong Answer.";
symbol = "×";
}
// Time Limit Exceed ?
else if (!Boolean.logicalAnd(accepted, (timeCost / 1E6) <= this.timeLimitMS)) {
accepted = false;
message = "Time Limit Exceed.";
symbol = "▲";
}
this.resultStatistics.append(symbol).append(" ");
System.err.println(message);
} catch (IOException e) {
e.printStackTrace();
this.resultStatistics.append("? ");
System.err.println("Unexpected Error !");
}
}
public void gracefullyExit(boolean closeStreams, boolean exit) {
System.err.println("===== Begin gracefully exit =====");
/* Judge case before exit */
this.judgeCase();
/* Flush and close the System.in stream. */
// Nobody cares the input stream.
/* Flush and close the System.out stream. */
System.out.flush();
if (closeStreams) {
System.out.close();
}
/* Flush and close the System.err stream. */
System.err.println("===== End gracefully Exit. =====");
System.err.flush();
if (closeStreams) {
System.err.close();
}
/* Exit the JVM */
if (exit) {
System.exit(0);
}
}
private void setThreadUncaughtExceptionHandler(Thread thread) {
thread.setUncaughtExceptionHandler((t, e) -> {
/* Handle the exception. */
this.displayThrowable(t, e);
/* Gracefully exit. */
gracefullyExit(true, true);
});
}
private void displayThrowable(Thread t, Throwable e) {
System.err.println("===== Exception Occurred. =====");
System.err.println("Current Thread: " + t);
e.printStackTrace();
System.err.println("\n");
}
private void registerJudgerUncaughtExceptionHandler() {
this.setThreadUncaughtExceptionHandler(Thread.currentThread());
}
public Judger println(Object object) {
if (this.debugPrintFunctions) {
System.out.println(object);
}
return this;
}
public Judger print(Object object) {
if (this.debugPrintFunctions) {
System.out.print(object);
}
return this;
}
public Judger printf(String format, Object... args) {
if (this.debugPrintFunctions) {
System.out.printf(format, args);
}
return this;
}
public Judger safeRun(Runnable runnable) {
try {
runnable.run();
} catch (Exception e) {
/* Display Throwable */
this.displayThrowable(Thread.currentThread(), e);
/* Handle Throwable */
// Store judger context
StringBuilder $resultStatistics = this.resultStatistics;
this.resultStatistics = new StringBuilder();
// Gracefully exit (but don't exit the JVM)
this.gracefullyExit(false, false);
// Load judger context
this.resultStatistics = $resultStatistics;
}
return this;
}
public abstract static class MermaidBuilder {
public final Style style = new Style(this);
public final Counter counter = new Counter();
private ArrayList<String> mermaidStatements;
public MermaidBuilder() {
this.reset();
}
public abstract void preStatement();
public abstract void postStatement();
public void uniqueStatement() {
HashSet<String> visited = new HashSet<>();
ArrayList<String> result = new ArrayList<>();
for (String statement : this.mermaidStatements) {
if (!visited.contains(statement)) {
visited.add(statement);
result.add(statement);
}
}
this.mermaidStatements = result;
}
public void reset() {
this.mermaidStatements = new ArrayList<>();
this.preStatement();
}
public String build() {
/* PostStatement */
this.postStatement();
/* Build Mermaid String */
StringBuilder mermaidStringBuilder = new StringBuilder();
for (String mermaidStatement : this.mermaidStatements) {
mermaidStringBuilder.append(mermaidStatement).append("\n");
}
return mermaidStringBuilder.toString();
}
protected abstract Stream<String> parseNode(Object... args);
public void addStatement(String statement) {
this.mermaidStatements.add(statement);
}
public void addNode(Object... args) {
Optional.ofNullable(this.parseNode(args)).ifPresent(o -> o.forEach(statement -> {
if (statement != null) {
this.addStatement(statement);
}
}));
}
public void print() {
System.out.println();
System.out.println("===== Begin Mermaid Statements =====");
System.out.println(this.build());
System.out.println("===== End Mermaid Statements =====");
}
public void image() {
String base64 = new String(Base64.getEncoder().encode(this.build().getBytes()));
String URL = "https://mermaid.ink/img/" + base64;
try {
Desktop.getDesktop().browse(new URI(URL));
} catch (Exception e) {
e.printStackTrace();
}
}
public String ofID(Object... args) {
StringBuilder id = new StringBuilder();
for (int i = 0; i < args.length; i++) {
id.append(args[i]);
if (i != args.length - 1) {
id.append("#");
}
}
return id.toString();
}
public String uuid() {
return UUID.randomUUID().toString().substring(0, 8);
}
public static class Style {
private final MermaidBuilder builder;
public Style(MermaidBuilder builder) {
this.builder = builder;
}
public void stress(String nodeID, String color) {
builder.addStatement(String.format("style %s fill: %s,stroke: #333,stroke-width: 4px", nodeID, color));
}
public void css(String nodeID, String css) {
builder.addStatement(String.format("style %s %s", nodeID, css));
}
}
public static class Counter {
private int counter;
public Counter() {
this.reset();
}
public void reset() {
this.counter = 0;
}
public int increment(int delta) {
return this.counter += delta;
}
public int increment() {
return this.increment(+1);
}
public int get() {
return counter;
}
public void set(int value) {
this.counter = value;
}
}
}
public static class MarkdownBuilder {
public static String buildMatrix(Object origin, Object[] rows, Object[] cols, Object[][] data) {
/* Default value */
if (origin == null) {
origin = "";
}
if (rows == null) {
rows = new String[data.length];
for (int i = 0; i < data.length; i++) {
rows[i] = String.valueOf(i);
}
}
if (cols == null) {
cols = new String[data[0].length];
for (int i = 0; i < data[0].length; i++) {
cols[i] = String.valueOf(i);
}
}
/* Construct */
StringBuilder result = new StringBuilder();
result.append("\\begin{bmatrix}\n");
for (int i = 0; i < data.length; i++) {
// first row
if (i == 0) {
for (int j = 0; j < cols.length; j++) {
// origin cell
if (j == 0) {
result.append(origin);
continue;
}
result.append("&").append(cols[j]);
}
result.append("\\\\\n");
continue;
}
// first column
for (int j = 0; j < data[i].length; j++) {
if (j == 0) {
result.append(rows[i]);
continue;
}
result.append("&").append(data[i][j]);
}
result.append("\\\\").append("\n");
}
result.append("\\end{bmatrix}\n");
return result.toString();
}
public static String buildTable(Object origin, Object[] rows, Object[] cols, Object[][] data) {
/* Default value */
if (origin == null) {
origin = "";
}
if (rows == null) {
rows = new String[data.length];
for (int i = 0; i < data.length; i++) {
rows[i] = String.valueOf(i);
}
}
if (cols == null) {
cols = new String[data[0].length];
for (int i = 0; i < data[0].length; i++) {
cols[i] = String.valueOf(i);
}
}
/* Construct */
StringBuilder result = new StringBuilder().append("\n");
for (int i = 0; i < data.length; i++) {
// first row
if (i == 0) {
for (int j = 0; j < cols.length; j++) {
// origin cell
if (j == 0) {
result.append("").append(origin).append("");
continue;
}
result.append(cols[j]).append("");
}
result.append("\n");
// second row -> table properties
for (int j = 0; j < cols.length; j++) {
result.append(" :-: ");
}
result.append("").append("\n");
}
for (int j = 0; j < data[i].length; j++) {
// first column
if (j == 0) {
result.append("").append(rows[i]).append("");
}
result.append(data[i][j]).append("");
}
result.append("\n");
}
return result.append("\n").toString();
}
}
}
public static Judger judger = new Judger("/Cases/Two's Sum");
public static void main(String[] args) {
for (Scanner scanner : judger) {
int a = scanner.nextInt();
int b = scanner.nextInt();
int sum = a + b;
System.out.println(sum);
}
}
public static Judger judger = new Judger("/Cases/Two's Sum")
.redirectError()
.enablePrettyFormat()
.ignoreExceptCase("CASES")
.ignoreCase("CASE5")
.joinCase("CASE3")
.setMaxExpectedInputLines(1)
.setTimeLimitMS(1000);
public static void main(String[] args) {
for (Scanner scanner : judger) {
int a = scanner.nextInt();
int b = scanner.nextInt();
int sum = a + b;
System.out.println(sum);
}
}
解释：让
Judger从"/Cases/Lab5/COIN CHANGING"路径下扫描所有的案例文件，然后重定向错误到合适的路径，并且期望启用自由格式输出，还需要设置期望输出的最大显示限制，此外，每个案例的运行时间限定为 1000ms。所有
被扫描到且有效的案例文件将被创建为Scanner实例序列，通过foreach语法糖即可获得所有的案例实例