禁用启用员工账号和编辑员工信息

controller里更新的写法

 /**
     * 根据id修改员工信息
     * @param employee
     * @return
     */
    //前端f12看出来是put
    @PutMapping//从sessoin里获取id，前端是多组数据封装json对象用employee接收
    public R<String> update(HttpServletRequest request,@RequestBody Employee employee){
        log.info(employee.toString());

        long id = Thread.currentThread().getId();
        log.info("线程id为：{}",id);
        //Long empId = (Long)request.getSession().getAttribute("employee");
        //employee.setUpdateTime(LocalDateTime.now());
        //employee.setUpdateUser(empId);
        employeeService.updateById(employee);//Iservice里的方法

        return R.success("员工信息修改成功");
    }

实质是update，

但是禁用启用信息时，传id，id在数据库里是19位，前端js只能保证前16位精度，后几位精度就不保证了

解决方法是后端传long数据时转成String

于是导入JacksonObjectMapper，扩展消息转换器，把long转换为string，不用jackson的话就是默认用springmvc的，现在得扩展

导完后得在springmvcconfig里配置

  /**
     * 扩展mvc框架的消息转换器
     * @param converters
     */
    //重写方法，扩展自己的转换器
    @Override
    protected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        log.info("扩展消息转换器...");
        //创建消息转换器对象
        MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();
        //设置对象转换器，底层使用Jackson将Java对象转为json
        messageConverter.setObjectMapper(new JacksonObjectMapper());
        //将上面的消息转换器对象追加到mvc框架的转换器集合中
        //把自己的转换器放在最前面，优先使用
        converters.add(0,messageConverter);
    }

导入的jackson，不用自己写

package com.itheima.reggie.common;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;
import java.math.BigInteger;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import static com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES;

/**
 * 对象映射器:基于jackson将Java对象转为json，或者将json转为Java对象
 * 将JSON解析为Java对象的过程称为 [从JSON反序列化Java对象]
 * 从Java对象生成JSON的过程称为 [序列化Java对象到JSON]
 */
public class JacksonObjectMapper extends ObjectMapper {

    public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";
    public static final String DEFAULT_DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
    public static final String DEFAULT_TIME_FORMAT = "HH:mm:ss";

    public JacksonObjectMapper() {
        super();
        //收到未知属性时不报异常
        this.configure(FAIL_ON_UNKNOWN_PROPERTIES, false);

        //反序列化时，属性不存在的兼容处理
        this.getDeserializationConfig().withoutFeatures(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);


        SimpleModule simpleModule = new SimpleModule()
                .addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)))
                .addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)))
                .addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)))

                .addSerializer(BigInteger.class, ToStringSerializer.instance)
                .addSerializer(Long.class, ToStringSerializer.instance)
                .addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)))
                .addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)))
                .addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));

        //注册功能模块 例如，可以添加自定义序列化器和反序列化器
        this.registerModule(simpleModule);
    }
}