基于常用json框架介绍和Jackson返回结果处理方式
目录
- json框架介绍,Jackson返回结果处理
- 1、常用框架 阿里 fastjson,谷歌gson等
- 2、jackson处理相关自动
- 使用jackson返回json数据
- 1、SpringMVC如何返回json数据
- 2、例子
json框架介绍,Jackson返回结果处理
介绍常用json框架和注解的使用,自定义返回json结构和格式
1、常用框架 阿里 fastjson,谷歌gson等
JavaBean序列化为Json,性能:Jackson > FastJson > Gson > Json-lib 同个结构
Jackson、FastJson、Gson类库各有优点,各有自己的专长
空间换时间,时间换空间
2、jackson处理相关自动
- 指定字段不返回:@JsonIgnore
- 指定日期格式:@JsonFormat(pattern="yyyy-MM-dd hh:mm:ss",locale="zh",timezone="GMT+8")
- 空字段不返回:@JsonInclude(Include.NON_NUll)
- 指定别名:@JsonProperty
实体类代码如下:
public class rData { @JsonIgnore private String code; @JsonProperty(value = "agenum") private int age; @JsonFormat(pattern="yyyy-MM-dd hh:mm:ss",locale="zh",timezone="GMT+8") private Date createDate; @JsonInclude(JsonInclude.Include.NON_NULL) private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } public Date getCreateDate() { return createDate; } public void setCreateDate(Date createDate) { this.createDate = createDate; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getCode() { return code; } public void setCode(String code) { this.code = code; } public rData(String code, int age) { this.code = code; this.age = age; } public rData(String code, int age, Date createDate, String name) { this.code = code; this.age = age; this.createDate = createDate; this.name = name; } }
测试类代码:
@RestController public class HttpController { @GetMapping("/testjson") public Object param6(){ return new rData("jackson",1,new Date(),"lion"); } }
结果:
{"createDate":"2018-09-18 09:36:31","name":"lion","agenum":1}
code被忽略了,所以不显示;age被别名代替"agenum"
使用jackson返回json数据
1、SpringMVC如何返回json数据
1.1、添加jar包
<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.5</version> </dependency>
1.2、配置spring文件,添加mvc命名空间和约束等
xmlns:mvc="http://www.springframework.org/schema/mvc" http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd <mvc:annotation-driven/>
1.3、方法上添加@ResponseBody
@ResponseBody
2、例子
2.1、配置pom.xml
<dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.0.8.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>5.0.8.RELEASE</version> </dependency> <!-- Spring的核心工具包--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>5.0.8.RELEASE</version> </dependency> <!--在基础IOC功能上提供扩展服务,还提供许多企业级服务的支持,有邮件服务、任务调度、远程访问、缓存以及多种视图层框架的支持--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>5.0.8.RELEASE</version> </dependency> <!-- Spring IOC的基础实现,包含访问配置文件、创建和管理bean等 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>5.0.8.RELEASE</version> </dependency> <!-- Spring context的扩展支持,用于MVC方面 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>5.0.8.RELEASE</version> </dependency> <!-- Spring表达式语言 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-expression</artifactId> <version>5.0.8.RELEASE</version> </dependency> <!--springAop开发必须加入的包--> <dependency> <groupId>aopalliance</groupId> <artifactId>aopalliance</artifactId> <version>1.0</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.13</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> <version>5.0.8.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>5.0.8.RELEASE</version> </dependency> <!--jackson返回json--> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.5</version> </dependency> </dependencies>
2.2、配置spring.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!--扫描controller--> <context:component-scan base-package="com"></context:component-scan> <!--视图解析器--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!--jsp所在位置--> <property name="prefix" value="/"></property> <!--jsp文件后缀名--> <property name="suffix" value=".jsp"></property> </bean> <mvc:annotation-driven /> <!--注解驱动--> </beans>
2.3、配置web.xml
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <servlet> <servlet-name>springMvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!--加载spring配置文件,原来是通过 ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");--> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring.xml</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>springMvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!--处理post乱码--> <filter> <filter-name>characterEncodingFilter</filter-name> <filter-class> org.springframework.web.filter.CharacterEncodingFilter </filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
2.4、添加User实体类
package com.fan.entity; import java.util.Arrays; import java.util.Date; public class User { private String username; private String password; private int[] box; private Date date; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public int[] getBox() { return box; } public void setBox(int[] box) { this.box = box; } public Date getDate() { return date; } public void setDate(Date date) { this.date = date; } @Override public String toString() { return "User{" + "username='" + username + '\'' + ", password='" + password + '\'' + ", box=" + Arrays.toString(box) + ", date=" + date + '}'; } }
2.5、 TestJsonController测试类
@Controller public class TestJsonController { //http://localhost:8080/testjson1 @RequestMapping("/testjson1") @ResponseBody //返回json字符串注解 public User test(){ User user=new User(); user.setUsername("malijuan"); user.setPassword("123"); user.setBox(new int[]{1,2,3}); user.setDate(new Date()); return user; } //http://localhost:8080/testjson2 @RequestMapping("/testjson2") @ResponseBody //返回json字符串注解 public List test2(){ User user=new User(); List list=new ArrayList(); for(int i=0;i<5;i++){ user.setUsername("malijuan"); user.setPassword("123"); user.setBox(new int[]{1,2,3}); user.setDate(new Date()); list.add(user); } return list; } }
2.6、启动tomcat测试
测试1
测试2
以上为个人经验,希望能给大家一个参考,也希望大家多多支持我们。
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