ObjectMapper 忽略字段大小写
核心代码:
ObjectMapper mapper = new ObjectMapper(); mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); mapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);
例子:
import com.fasterxml.jackson.databind.DeserializationFeature; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.MapperFeature; import com.fasterxml.jackson.databind.ObjectMapper; public class Test{ public static void main(String[] args) { try { A a = new A(); a.lastname = "jack"; ObjectMapper mapper = new ObjectMapper(); mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); mapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true); A2 convertValue = new A2(); mapper.updateValue(convertValue, a); System.out.println(convertValue); } catch (JsonMappingException e) { e.printStackTrace(); } } public static class A{ String lastname; public String getLastname() { return lastname; } public void setLastname(String lastname) { this.lastname = lastname; } } public static class A2{ String lastName; public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } @Override public String toString() { return "A2 [lastName=" + lastName + "]"; } } }
ObjectMapper 的一些坑
相信做过Java 开发对这个类应该不陌生,没错,这个类是jackson提供的,主要是用来把对象转换成为一个json字符串返回到前端,
现在大部分数据交换都是以json来传输的,所以这个很重要,那你到底又对这个类有着有多少了解呢,下面我说一下我遇到的一些坑
首先,先把我要说的几个坑需要设置的属性贴出来先
ObjectMapper objectMapper = new ObjectMapper(); //序列化的时候序列对象的所有属性 objectMapper.setSerializationInclusion(Include.ALWAYS); //反序列化的时候如果多了其他属性,不抛出异常 objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); //如果是空对象的时候,不抛异常 objectMapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false); //取消时间的转化格式,默认是时间戳,可以取消,同时需要设置要表现的时间格式 objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false); objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"))
简单说一下这个类的基本用法,以下采用代码块加截图的形式来说明和部分文字件数
package com.shiro.test; import java.text.SimpleDateFormat<p>本文来源gao!daima.com搞$代!码#网#</p>; import java.util.Date; import com.fasterxml.jackson.annotation.JsonInclude.Include; import com.fasterxml.jackson.databind.DeserializationFeature; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.SerializationFeature; public class Main2 { public static void main(String[] args) throws Exception{ ObjectMapper objectMapper = new ObjectMapper(); //序列化的时候序列对象的所有属性 objectMapper.setSerializationInclusion(Include.ALWAYS); //取消时间的转化格式,默认是时间戳,可以取消,同时需要设置要表现的时间格式 objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false); objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")); Person person = new Person(1, "zxc", new Date()); //这是最简单的一个例子,把一个对象转换为json字符串 String personJson = objectMapper.writeValueAsString(person); System.out.println(personJson); //默认为true,会显示时间戳 objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, true); personJson = objectMapper.writeValueAsString(person); System.out.println(personJson); } }