场景一: 数据库存储性别为1男，2女，页面输出要展示男 或 女
使用@JsonSerialize注解。
@Data
public class Human {
private String name;
private Integer age;
@JsonSerialize(using = SexSerializer.class)
private Integer sex;
}
public class SexSerializer extends StdSerializer<Integer> {
private SexSerializer() {
super(Integer.class);
}
@Override
public void serialize(Integer value, JsonGenerator gen, SerializerProvider provider) throws IOException {
if(value==1){
gen.writeString("male");
}else if(value==2){
gen.writeString("female");
}else {
gen.writeString("unKnow");
}
}
}
场景二: 某金融项目中，需要为所有金额添加单位
//数据类
public class Money {
private BigDecimal value;
}
//序列号类
public class MoneySerializer extends StdSerializer<BigDecimal> {
public MoneySerializer() {
super(BigDecimal.class);
}
@Override
public void serialize(BigDecimal value, JsonGenerator gen, SerializerProvider provider) throws IOException {
gen.writeString("¥"+value);
}
}
//将序列化配置添加进SimpleModule，在将SimpleModule注册进ObjectMapper
//这样全局都可以使用
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.addSerializer(BigDecimal.class,new MoneySerializer());
mapper.registerModule(module);
场景三:字符串为null时返回””
//自定义String null值的序列化对象
public class NullStringSerializer extends StdSerializer<Object> {
public NullStringSerializer() {
super(Object.class);
}
@Override
public void serialize(Object value, JsonGenerator gen, SerializerProvider provider) throws IOException {
gen.writeString("");
}
}
//将自定义null值序列号对象注册进序列化装饰器
@Component
public class CustomNullSerializerModifier extends BeanSerializerModifier {
@Autowired
private NullStringSerializer nullStringSerializer;
@Override
public List<BeanPropertyWriter> changeProperties(SerializationConfig config, BeanDescription beanDesc, List<BeanPropertyWriter> beanProperties) {
for (BeanPropertyWriter writer : beanProperties) {
Class<?> rawClass = writer.getType().getRawClass();
if(rawClass.isAssignableFrom(String.class)){
writer.assignNullSerializer(nullStringSerializer);
}
}
return beanProperties;
}
}
//将装饰器注册进ObjectMapper对象，这样就可以将全局的null String改为""
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setSerializerFactory(objectMapper.getSerializerFactory().withSerializerModifier(nullSerializerModifier));