SSH : Spring Struct Hibernate
SSM :Spring SpringMVC MyBatis
SpringBoot :Spring
- 什麼是JSON:一種輕量級的數據交換格式
- JSON和JS的關係:JSON是JS對象的字符串表達式,它使用文本表示一個JS對象的信息,本質是一個字符串
- JSON和JS互轉方法:
JSON.parse() JSON.stringify();
//將js對象轉換成json字符串
let str = JSON.stringify(user);
console.log(str);
//將json字符串轉換爲js對象
let user2 = JSON.parse(str);
console.log(user2.age,user2.name,user2.sex);
- 向前端傳遞數據
@RestController
public class JsonController {
@RequestMapping("/j1")
public String json1(){
return "string";
}
@RequestMapping(value = "/j2",produces ="application/json;charset=utf-8" )
public String json2(){
return "{\"name\":\"凱波\"}";
}
}
導入對應依賴
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.10.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.62</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.10</version>
</dependency>
- 1.編寫實體類
package com.yang.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
private String name;
private int age;
private String sex;
}
- 2.導入lombok
- 3.編寫controller控制層
通過JSON
package com.yang.controller;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.yang.pojo.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.Arrays;
import java.util.List;
@RestController
public class JsonController {
@RequestMapping("/o1")
public String json3() throws JsonProcessingException {
ObjectMapper mapper = new ObjectMapper();
User user1 = new User("楊凱波",3,"男");
User user2 = new User("楊凱波",3,"男");
User user3 = new User("楊凱波",3,"男");
User user4 = new User("楊凱波",3,"男");
User user5 = new User("楊凱波",3,"男");
List<User> users = Arrays.asList(user1, user2, user3, user4, user5);
return mapper.writeValueAsString(users);
}
}
通過FastJson
@RequestMapping("/fast")
public String test(){
User user1 = new User("楊凱波",3,"男");
User user2 = new User("楊凱波",3,"男");
User user3 = new User("楊凱波",3,"男");
User user4 = new User("楊凱波",3,"男");
User user5 = new User("楊凱波",3,"男");
List<User> users = Arrays.asList(user1, user2, user3, user4, user5);
String jsonStr = JSON.toJSONString(users);
System.out.println(jsonStr);
List<User> list = JSON.parseObject(jsonStr,List.class);
System.out.println(list);
return jsonStr;
}
- json後端出現亂碼解決方法
- 1.註解解決
@RequestMapping(value = "/j2",produces ="application/json;charset=utf-8" )
- 2.SpringMVC配置JSON亂碼處理(多)
<!--解決亂碼固定的-->
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<constructor-arg value="UTF-8"/>
</bean>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
<property name="failOnEmptyBeans" value="false"/>
</bean>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
爲防萬一,pom如下
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.yang</groupId>
<artifactId>SPRING</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies><!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.2</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.2.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.10.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.62</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.10</version>
</dependency>
</dependencies>
</project>