maven+WEB IDEA子目录下创建lib添加jar, 自由配置过滤器
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>
以上是提醒 , 正文从这里开始
这里使用jackson ,第一步导入包:
<dependencies>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.8</version>
</dependency>
</dependencies>
第二步配置web.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<!--1.注册servlet-->
<servlet>
<servlet-name>SpringMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!--通过初始化参数指定SpringMVC配置文件的位置，进行关联-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc-servlet.xml</param-value>
</init-param>
<!-- 启动顺序，数字越小，启动越早 -->
<load-on-startup>1</load-on-startup>
</servlet>
<!--所有请求都会被springmvc拦截 -->
<servlet-mapping>
<servlet-name>SpringMVC</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
第三步配置springmvc-servlet.xml文件
<?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: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
https://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 自动扫描指定的包，下面所有注解类交给IOC容器管理 -->
<context:component-scan base-package="com.it.controller"/>
<!-- 视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
id="internalResourceViewResolver">
<!-- 前缀 -->
<property name="prefix" value="/WEB-INF/jsp/" />
<!-- 后缀 -->
<property name="suffix" value=".jsp" />
</bean>
</beans>
第四步 编写实体类
@org.springframework.stereotype.Controller
//@RestController 指定该类下所有方法返回值变成json ,可以不用再写@ResponseBody
//json就是js的字符串 , 用于与java对象的转换
public class Controller {
//手动指定utf-8防止乱码,此方法不够强大
@RequestMapping(value ="/json1",produces ="application/json;charset=utf-8")
@ResponseBody //指定方法返回类型变成json
public String jackson1()throws JsonProcessingException {
ObjectMapper mapper =new ObjectMapper();
User user =new User("jackson哈哈",1,"json");
String str = mapper.writeValueAsString(user);
return str;
}
//测试多对象
@RequestMapping("/json2")
@ResponseBody
public String jackson2()throws JsonProcessingException {
ObjectMapper mapper =new ObjectMapper();
User json1 =new User("1号",1,"json");
User json2 =new User("2号",1,"json");
User json3 =new User("3号",1,"json");
User json4 =new User("4号",1,"json");
List users =new ArrayList<>();
users.add(json1);
users.add(json2);
users.add(json3);
users.add(json4);
String str = mapper.writeValueAsString(users);
return str;
}
@RequestMapping("/json3")
public String jackson3()throws JsonProcessingException {
ObjectMapper mapper =new ObjectMapper();
Date date =new Date();
String str = mapper.writeValueAsString(date);
return str;
}
@RequestMapping("/json4")
@ResponseBody
public String jackson4()throws JsonProcessingException {
ObjectMapper mapper =new ObjectMapper();
//不使用时间差的方式
mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS,false);
SimpleDateFormat sdf =new SimpleDateFormat("YYY-MM-dd HH:mm:ss");
Date date =new Date();
//指定日期格式
return mapper.writeValueAsString(sdf.format(date));
}
}
第五步 可以将其抽取成工具类
import java.text.SimpleDateFormat;
import java.util.Date;
public class DateUtils {
public static String getJson(Object object)throws JsonProcessingException {
return getJson(object,"yyyy-MM-dd HH:mm:ss");
}
public static String getJson(Object object,String dateFormat)throws JsonProcessingException {
ObjectMapper mapper =new ObjectMapper();
mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS,false);
SimpleDateFormat sdf =new SimpleDateFormat(dateFormat);
ObjectMapper obj = mapper.setDateFormat(sdf);
return mapper.writeValueAsString(obj);
}
}
