1、在application.properties中设置

#编码格式
spring.http.encoding.force=true
spring.http.encoding.charset=UTF-8
spring.http.encoding.enabled=true
server.tomcat.uri-encoding=UTF-8

2、自己手写编码过滤器

//字符编码过滤器
@WebFilter(urlPatterns = "/*",filterName = "CharacterEncodingFilter")
public class CharacterEncodingFilter implements Filter{
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
 
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
 
        filterChain.doFilter(request , response);
    }
    @Override
    public void destroy() {
    }
}

3、使用java配置写一个字符编码配置类

/**
 * 中文乱码解决
 */
@Configuration
public class CharsetConfig extends WebMvcConfigurerAdapter {
    @Bean
    public HttpMessageConverter<String> responseBodyConverter() {
        StringHttpMessageConverter converter = new StringHttpMessageConverter(
                Charset.forName("UTF-8"));
        return converter;
    }
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        super.configureMessageConverters(converters);
        converters.add(responseBodyConverter());
    }
    @Override
    public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
        configurer.favorPathExtension(false);
    }
}

　　StringHttpMessageConverter是一个请求和响应信息的编码转换器，通过源码我们发现默认编码ISO-8859-1，不是UTF-8，所以我们只要通过上述配置将请求字符串转为UTF-8 即可。

WebMvcConfigurerAdapter 是springmvc的一个配置支配器类，我们可以实现我们感兴趣的方法。