修复JSON解析栈溢出部分问题

CHANGELOG.md

@@ -17,6 +17,7 @@
 * 【core  】      修复ArrayUtil.insert()不支持原始类型数组的问题（pr#874@Gitee）
 * 【core  】      修复HexUtil.isHexNumber()判断逻辑超出long的精度问题（issue#I62H7K@Gitee）
 * 【core  】      修复BiMap中未重写computeIfAbsent和putIfAbsent导致双向查找出问题（issue#I62X8O@Gitee）
+* 【json  】      修复JSON解析栈溢出部分问题（issue#2746@Github）
 
 -------------------------------------------------------------------------------------------------------------
 

hutool-json/src/main/java/cn/hutool/json/JSONParser.java

@@ -44,19 +44,26 @@ public class JSONParser {
 	public void parseTo(JSONObject jsonObject, Filter<MutablePair<String, Object>> filter) {
 		final JSONTokener tokener = this.tokener;
 
-		char c;
-		String key;
-
 		if (tokener.nextClean() != '{') {
 			throw tokener.syntaxError("A JSONObject text must begin with '{'");
 		}
+
+		char prev;
+		char c;
+		String key;
 		while (true) {
+			prev = tokener.getPrevious();
 			c = tokener.nextClean();
 			switch (c) {
 				case 0:
 					throw tokener.syntaxError("A JSONObject text must end with '}'");
 				case '}':
 					return;
+				case '{':
+				case '[':
+					if (prev == '{') {
+						throw tokener.syntaxError("A JSONObject can not directly nest another JSONObject or JSONArray.");
+					}
 				default:
 					tokener.back();
 					key = tokener.nextValue().toString();

hutool-json/src/main/java/cn/hutool/json/JSONTokener.java

@@ -158,6 +158,15 @@ public class JSONTokener {
 		return this.previous;
 	}
 
+	/**
+	 * Get the last character read from the input or '\0' if nothing has been read yet.
+	 *
+	 * @return the last character read from the input.
+	 */
+	protected char getPrevious() {
+		return this.previous;
+	}
+
 	/**
 	 * 读取下一个字符，并比对是否和指定字符匹配
 	 *
@@ -329,10 +338,18 @@ public class JSONTokener {
 				return this.nextString(c);
 			case '{':
 				this.back();
-				return new JSONObject(this, this.config);
+				try {
+					return new JSONObject(this, this.config);
+				} catch (final StackOverflowError e) {
+					throw new JSONException("JSONObject depth too large to process.", e);
+				}
 			case '[':
 				this.back();
-				return new JSONArray(this, this.config);
+				try {
+					return new JSONArray(this, this.config);
+				} catch (final StackOverflowError e) {
+					throw new JSONException("JSONArray depth too large to process.", e);
+				}
 		}
 
 		/*
@@ -341,7 +358,7 @@ public class JSONTokener {
 		 * characters until we reach the end of the text or a formatting character.
 		 */
 
-		StringBuilder sb = new StringBuilder();
+		final StringBuilder sb = new StringBuilder();
 		while (c >= ' ' && ",:]}/\\\"[{;=#".indexOf(c) < 0) {
 			sb.append(c);
 			c = this.next();

hutool-json/src/main/java/cn/hutool/json/XMLTokener.java

@@ -41,7 +41,7 @@ public class XMLTokener extends JSONTokener {
 	public String nextCDATA() throws JSONException {
 		char c;
 		int i;
-		StringBuilder sb = new StringBuilder();
+		final StringBuilder sb = new StringBuilder();
 		for (; ; ) {
 			c = next();
 			if (end()) {
@@ -65,7 +65,7 @@ public class XMLTokener extends JSONTokener {
 	 */
 	public Object nextContent() throws JSONException {
 		char c;
-		StringBuilder sb;
+		final StringBuilder sb;
 		do {
 			c = next();
 		} while (Character.isWhitespace(c));
@@ -98,9 +98,10 @@ public class XMLTokener extends JSONTokener {
 	 * @throws JSONException If missing ';' in XML entity.
 	 */
 	public Object nextEntity(char ampersand) throws JSONException {
-		StringBuilder sb = new StringBuilder();
+		final StringBuilder sb = new StringBuilder();
+		char c;
 		for (; ; ) {
-			char c = next();
+			c = next();
 			if (Character.isLetterOrDigit(c) || c == '#') {
 				sb.append(Character.toLowerCase(c));
 			} else if (c == ';') {
@@ -109,9 +110,38 @@ public class XMLTokener extends JSONTokener {
 				throw syntaxError("Missing ';' in XML entity: &" + sb);
 			}
 		}
-		String string = sb.toString();
+		return unescapeEntity(sb.toString());
-		Object object = entity.get(string);
+	}
-		return object != null ? object : ampersand + string + ";";
+
+	/**
+	 * Unescape an XML entity encoding;
+	 *
+	 * @param e entity (only the actual entity value, not the preceding & or ending ;
+	 * @return Unescape str
+	 */
+	static String unescapeEntity(final String e) {
+		// validate
+		if (e == null || e.isEmpty()) {
+			return "";
+		}
+		// if our entity is an encoded unicode point, parse it.
+		if (e.charAt(0) == '#') {
+			final int cp;
+			if (e.charAt(1) == 'x' || e.charAt(1) == 'X') {
+				// hex encoded unicode
+				cp = Integer.parseInt(e.substring(2), 16);
+			} else {
+				// decimal encoded unicode
+				cp = Integer.parseInt(e.substring(1));
+			}
+			return new String(new int[]{cp}, 0, 1);
+		}
+		final Character knownEntity = entity.get(e);
+		if (knownEntity == null) {
+			// we don't know the entity so keep it encoded
+			return '&' + e + ';';
+		}
+		return knownEntity.toString();
 	}
 
 	/**

hutool-json/src/test/java/cn/hutool/json/Issue2555Test.java

@@ -1,3 +1,5 @@
+package cn.hutool.json;
+
 import cn.hutool.json.JSON;
 import cn.hutool.json.JSONConfig;
 import cn.hutool.json.JSONObject;

hutool-json/src/test/java/cn/hutool/json/Issue2746Test.java

@@ -0,0 +1,23 @@
+package cn.hutool.json;
+
+import cn.hutool.core.util.StrUtil;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class Issue2746Test {
+	@Test
+	public void parseObjTest() {
+		final String str = StrUtil.repeat("{", 1500) + StrUtil.repeat("}", 1500);
+		try{
+			JSONUtil.parseObj(str);
+		} catch (final JSONException e){
+			Assert.assertTrue(e.getMessage().startsWith("A JSONObject can not directly nest another JSONObject or JSONArray"));
+		}
+	}
+
+	@Test(expected = JSONException.class)
+	public void parseTest() {
+		final String str = StrUtil.repeat("[", 1500) + StrUtil.repeat("]", 1500);
+		JSONUtil.parseArray(str);
+	}
+}

hutool-json/src/test/java/cn/hutool/json/Issue2749Test.java

@@ -0,0 +1,32 @@
+package cn.hutool.json;
+
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Issue2749Test {
+
+	@Test
+	@Ignore
+	public void jsonObjectTest() {
+		final Map<String, Object> map = new HashMap<>(1, 1f);
+		Map<String, Object> node = map;
+		for (int i = 0; i < 1000; i++) {
+			//noinspection unchecked
+			node = (Map<String, Object>) node.computeIfAbsent("a", k -> new HashMap<String, Object>(1, 1f));
+		}
+		node.put("a", 1);
+		final String jsonStr = JSONUtil.toJsonStr(map);
+
+		@SuppressWarnings("MismatchedQueryAndUpdateOfCollection")
+		final JSONObject jsonObject = new JSONObject(jsonStr);
+		Assert.assertNotNull(jsonObject);
+
+		// 栈溢出
+		//noinspection ResultOfMethodCallIgnored
+		jsonObject.toString();
+	}
+}