添加Json结构转换实现

src/org/nutz/json/JsonConvert.java

@@ -0,0 +1,297 @@
+package org.nutz.json;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+import org.nutz.lang.Lang;
+import org.nutz.lang.Streams;
+
+/**
+ * Json转换.
+ * <p> 将一种JSON结构转换成另外一种JSON结构.例:
+ * <pre>
+ *  {
+ *      "age":"123",
+ *      "name":"juqkai"
+ *  }
+ *  转换成:
+ *  {
+ *      "年龄":"123",
+ *      "姓名":"juqkai"
+ *  }
+ * </pre>
+ * <p>要进行这样的转换需要预先配置一个对应关系的配置, 具体的配置关系说明如下:
+ * <ul>
+ * <li>使用原JSON一样的结构
+ * <li>有数组的, 只写第一个元素的结构
+ * <li>原结构中的值, 以字符串或字符串数组做为目标结构的对应关系
+ * <li>对应关系可以为数组
+ * <li>有数组的, 目标结构以key[].abc来代替数组
+ * <li>原结构数组层次强制限定一致, 目标结构中'[]'的索引按原结构中出现先后顺序进行匹配.
+ * </ul>
+ * <p> 例:
+ * <pre>
+ * 例1:
+ *  {
+ *      "age":"user.年龄",
+ *      "name":["user.name", "user.姓名"]
+ *  }
+ * 例2(原json:[{"name":"nutz"},{"name":"juqkai"}]):
+ * [{
+ *      "name":"[].姓名"
+ * }]
+ * 例3:
+ * {
+ *      users:[
+ *          {
+ *              "name":["people[].name", "users[].name"],
+ *              "age":"users[].name"
+ *          }
+ *      ]
+ * }
+ * </pre>
+ * @author juqkai(juqkai@gmail.com)
+ */
+public class JsonConvert {
+    //路径
+    private LinkedList<String> paths = new LinkedList<String>();
+    private LinkedList<Integer> arrayIndex = new LinkedList<Integer>();
+    //关系
+    private Map<String, List<String>> relation = new HashMap<String, List<String>>();
+    private Map<String, Object> newobj = new HashMap<String, Object>();
+
+    public JsonConvert() {
+        newobj.put("obj", null);
+    }
+
+    /**
+     * 转换
+     * @param obj 目标对象
+     * @param model 对应关系
+     * @return 
+     */
+    public Object convert(Object obj, String model){
+        initRelation(model);
+        convertObj(obj);
+        return newobj.get("obj");
+    }
+    /**
+     * 转换对象
+     * @param obj
+     */
+    private void convertObj(Object obj) {
+        if(obj instanceof Map){
+            convertMap((Map<?, ?>) obj);
+        } else if(obj instanceof List){
+            convertList((List<?>) obj);
+        }
+    }
+    /**
+     * 转换map
+     * @param obj
+     */
+    private void convertMap(Map<?, ?> obj) {
+        for(Object key : obj.keySet()){
+            paths.addLast(key.toString());
+            renew(fetchPath(), obj.get(key));
+            convertObj(obj.get(key));
+            paths.removeLast();
+        }
+    }
+    /**
+     * 提取路径
+     * @return
+     */
+    private String fetchPath(){
+        StringBuffer sb = new StringBuffer();
+        boolean first = true;
+        for(String path : paths){
+            if(!first){
+                sb.append(".");
+            }
+            sb.append(path);
+            first = false;
+        }
+        return sb.toString();
+    }
+    /**
+     * 转换LIST
+     * @param val
+     */
+    private void convertList(List<?> val){
+        if(paths.size() <= 0){
+            paths.add("[]");
+        }else{
+            paths.addLast(paths.removeLast() + "[]");
+        }
+        for(int i = 0; i < val.size(); i++){
+            arrayIndex.add(i);
+            convertObj(val.get(i));
+            arrayIndex.remove();
+        }
+    }
+
+    /**
+     * 重建新对象
+     * @param path
+     * @param object
+     */
+    private void renew(String path, Object object) {
+        if(relation.containsKey(path)){
+            List<String> dests = relation.get(path);
+            for(String dest : dests){
+                new structure(dest, object).inject();
+            }
+        }
+    }
+
+
+    /**
+     * 构建新的对象
+     * @author juqkai(juqkai@gmail.com)
+     */
+    class structure{
+        private String[] keys;
+        private Object val;
+        private Integer arrayItem = 0;
+
+        private structure(String keys, Object obj){
+            keys = "obj." + keys;
+            this.keys = keys.split("\\.");
+            val = obj;
+        }
+
+        public void inject(){
+            injectMap(newobj, 0);
+        }
+
+        /**
+         * 注入MAP
+         * @param obj
+         * @param i
+         * @return 
+         */
+        @SuppressWarnings("unchecked")
+        private Object injectMap(Object obj, int i) {
+            String key = keys[i];
+            if(key.equals("[]")){
+                List<Object> list = new ArrayList<Object>();
+                if(obj != null){
+                    list = (List<Object>) obj;
+                }
+                injectList(list, i);
+                return list;
+            }
+            Map<String, Object> map = new HashMap<String, Object>();
+            if(obj != null){
+                map = (Map<String, Object>) obj;
+            }
+            //有Key的list
+            if(key.endsWith("[]")){
+                String k = key.substring(0, key.indexOf('['));
+                if(!map.containsKey(k)){
+                    map.put(k, new ArrayList<Object>());
+                }
+                injectList((List<Object>) map.get(k), i);
+                return map;
+            }
+
+            if(i == keys.length - 1){
+                map.put(key, val);
+                return map;
+            }
+            if(map.containsKey(key) && map.get(key) != null){
+                injectMap(map.get(key), i + 1);
+            } else {
+                map.put(key, injectMap(null, i + 1));
+            }
+            return map;
+        }
+
+        /**
+         * 注入List
+         * @param list
+         * @param i
+         */
+        @SuppressWarnings("unchecked")
+        private void injectList(List<Object> list, int i) {
+            int index = arrayIndex.get(arrayItem ++);
+            if(i == keys.length - 1){
+                list.set(index, val);
+                return;
+            }
+            if(list.size() <= index){
+                list.add(index, new HashMap<String, Object>());
+            }
+            injectMap((Map<String, Object>) list.get(index), i + 1);
+        }
+
+    }
+
+
+
+
+
+
+
+    /**
+     * 初始化关系
+     * @param model
+     */
+    private void initRelation(String model){
+        Object obj = Json.fromJson(Streams.fileInr(model));
+        loadRelation(obj, "");
+    }
+    /**
+     * 解析配置信息
+     * @param obj
+     * @param path
+     */
+    private void loadRelation(Object obj, String path) {
+        if(obj instanceof Map){
+            loadMapRelation((Map<?, ?>) obj, path);
+        } else if(obj instanceof List){
+            loadListRelation((List<?>) obj, path);
+        } else {
+            throw new RuntimeException("无法识别的类型!");
+        }
+    }
+    /**
+     * 解析List配置信息
+     * @param obj
+     * @param path
+     */
+    @SuppressWarnings("unchecked")
+    private void loadListRelation(List<?> obj, String path) {
+        if(obj.size() <= 0){
+            return;
+        }
+        if(obj.get(0) instanceof String){
+            relation.put(path, (List<String>) obj);
+            return;
+        }
+        loadRelation(obj.get(0), path + "[]");
+    }
+    /**
+     * 解析MAP配置信息
+     * @param obj
+     * @param path
+     */
+    private void loadMapRelation(Map<?, ?> obj, String path) {
+        for(Object key : obj.keySet()){
+            Object val = obj.get(key);
+            if(val instanceof String){
+                relation.put(path + space(path) + key.toString(), Lang.list(val.toString()));
+                continue;
+            }
+            loadRelation(obj.get(key), path + space(path) + key.toString());
+        }
+    }
+
+    private String space(String path){
+        return path == "" ? "" : ".";
+    }
+}