add json compare util

[FEATURE] JSON 比对 alibaba#1946

core/src/main/java/com/alibaba/fastjson2/util/CompareUtils.java

@@ -0,0 +1,212 @@
+package com.alibaba.fastjson2.util;
+
+import com.alibaba.fastjson2.JSONArray;
+import com.alibaba.fastjson2.JSONObject;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * 两个json比较<br/>
+ * 实现思路：<br/>
+ * 1，把json按照json path平铺展开<br/>
+ * 2，对平铺展开的json进行对比<br/>
+ * 3，返回对比接口<br/>
+ * <p>
+ * compare: 返回所有结果<br/>
+ * diff: 返回差异结果<br/>
+ * <p>
+ * * @author yanchangyou
+ */
+public class CompareUtils {
+
+    public static final String DIFF_TYPE_OF_MODIFY = "MODIFY";
+    public static final String DIFF_TYPE_OF_ADD = "ADD";
+    public static final String DIFF_TYPE_OF_REMOVE = "REMOVE";
+
+    /**
+     * 比较json是否相同
+     *
+     * @param json1 json1
+     * @param json2 json2
+     * @return result
+     */
+    public static boolean equals(JSONObject json1, JSONObject json2) {
+        JSONObject result = diff(json1, json2);
+        return result.isEmpty();
+    }
+
+    /**
+     * 比较json，只保留差异部分
+     *
+     * @param json1 json1
+     * @param json2 json2
+     * @return result
+     */
+    public static JSONObject diff(JSONObject json1, JSONObject json2) {
+        JSONObject result = compare(json1, json2);
+        List<String> equalPathList = getEqualsJSONPathList(result);
+        for (String path : equalPathList) {
+            result.remove(path);
+        }
+        return result;
+    }
+
+    /**
+     * 比较json
+     *
+     * @param json1 json1
+     * @param json2 json2
+     * @return result
+     */
+    public static JSONObject compare(JSONObject json1, JSONObject json2) {
+
+        JSONObject jsonPath1 = convertWithJsonPath(json1);
+        JSONObject jsonPath2 = convertWithJsonPath(json2);
+
+        JSONObject result = new JSONObject();
+        List<String> jsonPathList = new ArrayList<>();
+
+        jsonPathList.addAll(jsonPath1.keySet());
+        for (String path : jsonPath2.keySet()) {
+            if (!jsonPathList.contains(path)) {
+                jsonPathList.add(path);
+            }
+        }
+
+        for (String path : jsonPathList) {
+            boolean json1Contain = jsonPath1.containsKey(path);
+            boolean json2Contain = jsonPath2.containsKey(path);
+
+            JSONObject pathResult = new JSONObject();
+            if (json1Contain && !json2Contain) {
+                pathResult.put("equal", false);
+                pathResult.put("type", DIFF_TYPE_OF_REMOVE);
+            } else if (!json1Contain && json2Contain) {
+                pathResult.put("equal", false);
+                pathResult.put("type", DIFF_TYPE_OF_ADD);
+            } else if (json1Contain && json2Contain) {
+                Object value1 = json1.getByPath(path);
+                Object value2 = json2.getByPath(path);
+                pathResult = compareValue(value1, value2);
+                if (Boolean.FALSE.equals(pathResult.get("equal"))) {
+                    pathResult.put("type", DIFF_TYPE_OF_MODIFY);
+                }
+            }
+
+            result.put(path, pathResult);
+        }
+
+        return result;
+    }
+
+    /**
+     * 按照json path平铺展开
+     *
+     * @param json 入参json
+     * @return 返回 json object
+     */
+    private static JSONObject convertWithJsonPath(JSONObject json) {
+
+        JSONObject newMap = new JSONObject();
+        if (json == null) {
+            return newMap;
+        }
+        for (Map.Entry<String, Object> field : json.entrySet()) {
+            Object value = field.getValue();
+            String fieldName = buildJsonPathKey((field.getKey()));
+            if (value instanceof JSONObject || value instanceof JSONArray) {
+                JSONArray array;
+                boolean isArray = true;
+                if (value instanceof JSONObject) {
+                    array = new JSONArray(1);
+                    array.add(value);
+                    isArray = false;
+                } else {
+                    array = (JSONArray) value;
+                }
+                int index = 0;
+                for (Object item : array) {
+                    String arrayFieldName = fieldName.concat("[".concat(index + "").concat("]"));
+                    if (item instanceof JSONObject) {
+                        JSONObject subMap = convertWithJsonPath((JSONObject) item);
+                        for (Map.Entry<String, Object> entry : subMap.entrySet()) {
+                            String newKey = entry.getKey();
+                            if (!newKey.startsWith("[")) {
+                                newKey = ".".concat(newKey);
+                            }
+                            String newFieldName = isArray ? arrayFieldName.concat(newKey) : fieldName.concat(newKey);
+                            newMap.put((newFieldName), entry.getValue());
+                        }
+                    } else {
+                        newMap.put((arrayFieldName), item);
+                    }
+                    index++;
+                }
+            } else {
+                newMap.put((fieldName), value);
+            }
+        }
+        return newMap;
+    }
+
+    /**
+     * 比较值
+     *
+     * @param value1 value1
+     * @param value2 value2
+     * @return result
+     */
+    private static JSONObject compareValue(Object value1, Object value2) {
+        JSONObject result = new JSONObject();
+
+        boolean equal = Objects.equals(value1, value2);
+        result.put("equal", equal);
+
+        if (!equal) {
+            if (value1 != null && value2 != null) {
+                boolean typeEqual = (value1.getClass().equals(value2.getClass()));
+                result.put("typeEqual", typeEqual);
+            } else {
+                result.put("typeEqual", false);
+            }
+        }
+
+        return result;
+    }
+
+    /**
+     * 获取差异的json path列表
+     *
+     * @param jsonCompareResult json比较结果
+     * @return json path列表
+     */
+    private static List<String> getEqualsJSONPathList(JSONObject jsonCompareResult) {
+        List<String> equalPathList = new ArrayList<>();
+        for (Map.Entry<String, Object> entry : jsonCompareResult.entrySet()) {
+            if (Boolean.TRUE.equals(((JSONObject) entry.getValue()).get("equal"))) {
+                equalPathList.add(entry.getKey());
+            }
+        }
+        return equalPathList;
+    }
+
+    /**
+     * 处理特殊key，key中有点号，然后冲突
+     *
+     * @param key
+     * @return
+     */
+    static String buildJsonPathKey(String key) {
+        //TODO 避免json path解析报错，key包含特殊字符
+        if (key.contains("[")) {
+            key = key.replace("[", "").replace("]", "");
+        }
+        if (key.contains(".") || key.contains("-")) {
+            return "['".concat(key).concat("']");
+        }
+        return key;
+    }
+}