[Add] 初步完成架构

src/main/java/cn/codeyourlife/WebIdeApplication.java

@@ -15,9 +15,10 @@
 
 
 /**
- * 服务的主入口
- *
- * @author superzhan
+ * Author: [email protected]
+ * Copyright: http://codeyourlife.cn
+ * Platform: Win10 Jdk8
+ * Date: 2020/1/8
  */
 public final class WebIdeApplication {
 

src/main/java/cn/codeyourlife/compile/StringSourceCompiler.java

@@ -0,0 +1,115 @@
+package cn.codeyourlife.compile;
+
+import javax.tools.*;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class StringSourceCompiler {
+    private static Map<String, JavaFileObject> fileObjectMap = new ConcurrentHashMap<>();
+
+    /** 使用 Pattern 预编译功能 */
+    private static Pattern CLASS_PATTERN = Pattern.compile("class\\s+([$_a-zA-Z][$_a-zA-Z0-9]*)\\s*");
+
+    public static byte[] compile(String source, DiagnosticCollector<JavaFileObject> compileCollector) {
+        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+        JavaFileManager javaFileManager =
+                new TmpJavaFileManager(compiler.getStandardFileManager(compileCollector, null, null));
+
+        // 从源码字符串中匹配类名
+        Matcher matcher = CLASS_PATTERN.matcher(source);
+        String className;
+        if (matcher.find()) {
+            className = matcher.group(1);
+        } else {
+            throw new IllegalArgumentException("No valid class");
+        }
+
+        // 把源码字符串构造成JavaFileObject，供编译使用
+        JavaFileObject sourceJavaFileObject = new TmpJavaFileObject(className, source);
+
+        Boolean result = compiler.getTask(null, javaFileManager, compileCollector,
+                null, null, Arrays.asList(sourceJavaFileObject)).call();
+
+        JavaFileObject bytesJavaFileObject = fileObjectMap.get(className);
+        if (result && bytesJavaFileObject != null) {
+            return ((TmpJavaFileObject) bytesJavaFileObject).getCompiledBytes();
+        }
+        return null;
+    }
+
+    /**
+     * 管理JavaFileObject对象的工具
+     */
+    public static class TmpJavaFileManager extends ForwardingJavaFileManager<JavaFileManager> {
+        protected TmpJavaFileManager(JavaFileManager fileManager) {
+            super(fileManager);
+        }
+
+        @Override
+        public JavaFileObject getJavaFileForInput(Location location, String className, JavaFileObject.Kind kind) throws IOException {
+            JavaFileObject javaFileObject = fileObjectMap.get(className);
+            if (javaFileObject == null) {
+                return super.getJavaFileForInput(location, className, kind);
+            }
+            return javaFileObject;
+        }
+
+        @Override
+        public JavaFileObject getJavaFileForOutput(Location location, String className, JavaFileObject.Kind kind, FileObject sibling) throws IOException {
+            JavaFileObject javaFileObject = new TmpJavaFileObject(className, kind);
+            fileObjectMap.put(className, javaFileObject);
+            return javaFileObject;
+        }
+    }
+
+    /**
+     * 用来封装表示源码与字节码的对象
+     */
+    public static class TmpJavaFileObject extends SimpleJavaFileObject {
+        private String source;
+        private ByteArrayOutputStream outputStream;
+
+        /**
+         * 构造用来存储源代码的JavaFileObject
+         * 需要传入源码source，然后调用父类的构造方法创建kind = Kind.SOURCE的JavaFileObject对象
+         */
+        public TmpJavaFileObject(String name, String source) {
+            super(URI.create("String:///" + name + Kind.SOURCE.extension), Kind.SOURCE);
+            this.source = source;
+        }
+
+        /**
+         * 构造用来存储字节码的JavaFileObject
+         * 需要传入kind，即我们想要构建一个存储什么类型文件的JavaFileObject
+         */
+        public TmpJavaFileObject(String name, Kind kind) {
+            super(URI.create("String:///" + name + Kind.SOURCE.extension), kind);
+            this.source = null;
+        }
+
+        @Override
+        public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
+            if (source == null) {
+                throw new IllegalArgumentException("source == null");
+            }
+            return source;
+        }
+
+        @Override
+        public OutputStream openOutputStream() throws IOException {
+            outputStream = new ByteArrayOutputStream();
+            return outputStream;
+        }
+
+        public byte[] getCompiledBytes() {
+            return outputStream.toByteArray();
+        }
+    }
+}

src/main/java/cn/codeyourlife/controller/RunCodeController.java

@@ -0,0 +1,31 @@
+package cn.codeyourlife.controller;
+
+/**
+ * Author: [email protected]
+ * Copyright: http://codeyourlife.cn
+ * Platform: Win10 Jdk8
+ * Date: 2020/1/8
+ */
+public class RunCodeController {
+    private static final String defaultSource = "public class Run {\n"
+            + "    public static void main(String[] args) {\n"
+            + "        \n"
+            + "    }\n"
+            + "}";
+
+//    public String entry(Model model) {
+//        model.addAttribute("lastSource", defaultSource);
+//        return "ide";
+//    }
+//
+//    public String runCode(@RequestParam("source") String source,
+//                          @RequestParam("systemIn") String systemIn, Model model) {
+//        String runResult = executeStringSourceService.execute(source, systemIn);
+//        runResult = runResult.replaceAll(System.lineSeparator(), "<br/>"); // 处理html中换行的问题
+//
+//        model.addAttribute("lastSource", source);
+//        model.addAttribute("lastSystemIn", systemIn);
+//        model.addAttribute("runResult", runResult);
+//        return "ide";
+//    }
+}

src/main/java/cn/codeyourlife/execute/ByteUtils.java

@@ -0,0 +1,40 @@
+package cn.codeyourlife.execute;
+
+public class ByteUtils {
+
+    public static int byte2Int(byte[] b, int start, int len) {
+        int res = 0;
+        int end = start + len;
+        for (int i = start; i < end; i++) {
+            int cur = ((int) b[i]) & 0xff;
+            cur <<= (--len) * 8;
+            res += cur;
+        }
+        return res;
+    }
+
+    public static byte[] int2Byte(int num, int len) {
+        byte[] b = new byte[len];
+        for (int i = 0; i < len; i++) {
+            b[len - i - 1] = (byte) ((num >> (8 * i)) & 0xff);
+        }
+        return b;
+    }
+
+    public static String byte2String(byte[] b, int start, int len) {
+        return new String(b, start, len);
+    }
+
+    public static byte[] string2Byte(String str) {
+        return str.getBytes();
+    }
+
+    public static byte[] byteReplace(byte[] oldBytes, int offset, int len, byte[] replaceBytes) {
+        byte[] newBytes = new byte[oldBytes.length + replaceBytes.length - len];
+        System.arraycopy(oldBytes, 0, newBytes, 0, offset);
+        System.arraycopy(replaceBytes, 0, newBytes, offset, replaceBytes.length);
+        System.arraycopy(oldBytes, offset + len, newBytes, offset + replaceBytes.length,
+                oldBytes.length - offset - len);
+        return newBytes;
+    }
+}

src/main/java/cn/codeyourlife/execute/ClassModifier.java

@@ -0,0 +1,77 @@
+package cn.codeyourlife.execute;
+
+public class ClassModifier {
+    /**
+     * Class文件中常量池的起始偏移
+     */
+    private static final int CONSTANT_POOL_COUNT_INDEX = 8;
+
+    /**
+     * CONSTANT_UTF8_INFO常量的tag
+     */
+    private static final int CONSTANT_UTF8_INFO = 1;
+
+    /**
+     * 常量池中11种常量的长度，CONSTANT_ITEM_LENGTH[tag]表示它的长度
+     */
+    private static final int[] CONSTANT_ITEM_LENGTH = {-1, -1, -1, 5, 5, 9, 9, 3, 3, 5, 5, 5, 5};
+
+    /**
+     * 1个和2个字节的符号数，用来在classByte数组中取tag和len
+     * tag用u1个字节表示
+     * len用u2个字节表示
+     */
+    private static final int u1 = 1;
+    private static final int u2 = 2;
+
+    /**
+     * 要被修改的字节码文件
+     */
+    private byte[] classByte;
+
+    public ClassModifier(byte[] classByte) {
+        this.classByte = classByte;
+    }
+
+    /**
+     * 从0x00000008开始向后取2个字节，表示的是常量池中常量的个数
+     * @return 常量池中常量的个数
+     */
+    public int getConstantPoolCount() {
+        return ByteUtils.byte2Int(classByte, CONSTANT_POOL_COUNT_INDEX, u2);
+    }
+
+    /**
+     * 字节码修改器，替换字节码常量池中 oldStr 为 newStr
+     * @param oldStr
+     * @param newStr
+     * @return 修改后的字节码字节数组
+     */
+    public byte[] modifyUTF8Constant(String oldStr, String newStr) {
+        int cpc = getConstantPoolCount();
+        int offset = CONSTANT_POOL_COUNT_INDEX + u2;  // 真实的常量起始位置
+        for (int i = 1; i < cpc; i++) {
+            int tag = ByteUtils.byte2Int(classByte, offset, u1);
+            if (tag == CONSTANT_UTF8_INFO) {
+                int len = ByteUtils.byte2Int(classByte, offset + u1, u2);
+                offset += u1 + u2;
+                String str = ByteUtils.byte2String(classByte, offset, len);
+                if (str.equals(oldStr)) {
+                    byte[] strReplaceBytes = ByteUtils.string2Byte(newStr);
+                    byte[] intReplaceBytes = ByteUtils.int2Byte(strReplaceBytes.length, u2);
+                    // 替换新的字符串的长度
+                    classByte = ByteUtils.byteReplace(classByte, offset - u2, u2, intReplaceBytes);
+                    // 替换字符串本身
+                    classByte = ByteUtils.byteReplace(classByte, offset, len, strReplaceBytes);
+                    return classByte;  // 就一个地方需要改，改完就可以返回了
+                } else {
+                    offset += len;
+                }
+            } else {
+                offset += CONSTANT_ITEM_LENGTH[tag];
+            }
+        }
+        return classByte;
+    }
+
+}