82 lines
2.0 KiB
Markdown
82 lines
2.0 KiB
Markdown
# 使用Mixin注入Annotation定制序列化和反序列化
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当你需要定制化序列化一些LIB里面的类，你无法修改这些类的代码，你可以使用FASTJSON2的Minxin功能注入Annotation。
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比如：
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## 1. 要序列化的类
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```java
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public static class Product {
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public String name;
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}
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```
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## 2. 注入配置类
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```java
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public abstract class ProductMixin {
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@JSONField(name = "productName")
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String name;
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}
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```
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## 3. 注入配置 & 使用
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```java
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// 配置注入
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JSON.mixIn(Product.class, ProductMixin.class);
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// 使用
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Product product = new Product();
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product.name = "DataWorks";
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assertEquals("{\"productName\":\"DataWorks\"}", JSON.toJSONString(product));
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Product productParsed = JSON.parseObject("{\"productName\":\"DataWorks\"}", Product.class);
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assertEquals("DataWorks", productParsed.name);
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```
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## 4. 结合JSONCreator & JSONField(value=true)的例子
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如下的Address类，没有缺省构造函数，只有一个字段，我希望序列化结果为address字段的字符串。
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```java
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public static class Address {
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private final String address;
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public Address(String address) {
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this.address = address;
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}
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public String getAddress() {
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return address;
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}
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}
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```
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注入使用方式如下：
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```java
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static class AddressMixin {
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// 通过JSONCreator指定构造函数
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@JSONCreator
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public AddressMixin(@JSONField(value = true) String address) {
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}
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// 配置输出使用此字段
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@JSONField(value = true)
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public String getAddress() {
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return null;
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}
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}
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@Test
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public void test() {
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JSON.mixIn(Address.class, AddressMixin.class); // 通过mixin注入Annotation
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Address address = new Address("HangZhou");
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// 序列化输出结果为address字段
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String str = JSON.toJSONString(address);
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assertEquals("\"HangZhou\"", str);
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// 通过结果可以看出使用了JSONCreator指定的构造函数
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Address address1 = JSON.parseObject(str, Address.class);
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assertEquals(address.getAddress(), address1.getAddress());
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}
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```
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