Fastjson JSONObject深度复制

2023-09-06 00:37| 来源: 网络整理| 查看: 265

1，new JSONObject (Object) - 失败

2，Put All;

3，串行化复制;

总结：

如何对fajstjson JSONObject类型的数据进行深度复制，有几种方式呢？

1，new JSONObject (Object) - 失败

代码：

public static void main(String[] args) throws IOException, ClassNotFoundException { testNewJson(); } public static void testNewJson(){ System.out.println("====== new JSONObject fail ======="); JSONObject one = new JSONObject(); one.put("one","fish"); JSONObject two = new JSONObject(one); System.out.println("init: one: "+ one.toString()); System.out.println("init: two: "+ two.toString()); System.out.println("====== add grass ======="); two.put("two","grass"); System.out.println("change: one: "+ one.toString()); System.out.println("change: two: "+ two.toString()); System.out.println("====== new JSONObject fail ======="); }

结果：

====== new JSONObject fail ======= init: one: {"one":"fish"} init: two: {"one":"fish"} ====== add grass ======= change: one: {"one":"fish","two":"grass"} change: two: {"one":"fish","two":"grass"} ====== new JSONObject fail =======

new JSONObject(one) 这种方式失败了 new JSONObject(Object)深复制失败的原因

2，Put All;

代码：

public static void main(String[] args) throws IOException, ClassNotFoundException { testPutAllJson(); } public static void testPutAllJson(){ System.out.println("====== put all ======="); JSONObject one = new JSONObject(); one.put("one","fish"); JSONObject two = new JSONObject(); two.putAll(one); System.out.println("init: one: "+ one.toString()); System.out.println("init: two: "+ two.toString()); System.out.println("====== add fox ======="); two.put("two","fox"); System.out.println("change: one: "+ one.toString()); System.out.println("change: two: "+ two.toString()); System.out.println(); }

结果：

====== put all ======= init: one: {"one":"fish"} init: two: {"one":"fish"} ====== add fox ======= change: one: {"one":"fish"} change: two: {"one":"fish","two":"fox"}

putAll的方式行得通

3，串行化复制;

代码：

public static void main(String[] args) throws IOException, ClassNotFoundException { testDeppCopyJson(); } public static void testDeppCopyJson() throws IOException, ClassNotFoundException { System.out.println("====== serializable success ======="); JSONObject one = new JSONObject(); one.put("one","fish"); JSONObject two = CloneUtils.clone(one); two.putAll(one); System.out.println("init: one: "+ one.toString()); System.out.println("init: two: "+ two.toString()); System.out.println("====== add wolf ======="); two.put("two","wolf"); System.out.println("change: one: "+ one.toString()); System.out.println("change: two: "+ two.toString()); System.out.println(); }

串行化代码：

public class CloneUtils { public static T clone(T src) throws IOException, ClassNotFoundException { ObjectInputStream ois = getInputStream(src); //返回生成的新对象 @SuppressWarnings("unchecked") T cloneObj = (T) ois.readObject(); ois.close(); return cloneObj; } public static List deepCopy(List src) throws IOException, ClassNotFoundException { ObjectInputStream ois = getInputStream(src); @SuppressWarnings("unchecked") List dest = (List) ois.readObject(); ois.close(); return dest; } public static Map cloneMap(Map src) throws IOException, ClassNotFoundException { ObjectInputStream ois = getInputStream(src); @SuppressWarnings("unchecked") Map result = (Map) ois.readObject(); ois.close(); return result; } private static ObjectInputStream getInputStream(Object src) throws IOException, ClassNotFoundException { //写入字节流 ByteArrayOutputStream out = new ByteArrayOutputStream(); ObjectOutputStream obs = new ObjectOutputStream(out); obs.writeObject(src); obs.close(); //分配内存，写入原始对象，生成新对象 ByteArrayInputStream ios = new ByteArrayInputStream(out.toByteArray()); return new ObjectInputStream(ios); } }

结果：

====== serializable success ======= init: one: {"one":"fish"} init: two: {"one":"fish"} ====== add wolf ======= change: one: {"one":"fish"} change: two: {"one":"fish","two":"wolf"}

总结：

在使用fastjon JSONObject复制的时候，一般用第二种putAll的方式，如果大量使用，也可以考虑用第三种方式。

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