将RestTemplate的编码格式改为UTF-8,防止乱码问题

 //修改RestTemplate的编码格式为UTF-8
        RestTemplate restTemplate = new RestTemplate();
        List<HttpMessageConverter<?>> httpMessageConverters = restTemplate.getMessageConverters();
        httpMessageConverters.stream().forEach(httpMessageConverter -> {
            if(httpMessageConverter instanceof StringHttpMessageConverter){
                StringHttpMessageConverter messageConverter = (StringHttpMessageConverter) httpMessageConverter;
                messageConverter.setDefaultCharset(Charset.forName("UTF-8"));
            }
            //发送请求
        String jsonStr = restTemplate.getForEntity(url, String.class).getBody();

@Bean
    public RestTemplate restTemplate() {
        RestTemplate restTemplate = new RestTemplate();
        restTemplate.getMessageConverters().set(1, new StringHttpMessageConverter(StandardCharsets.UTF_8));
        return restTemplate;
    }

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"
       default-autowire="byName" default-lazy-init="true">
    <!--方式一、使用jdk的实现-->
    <bean id="ky.requestFactory" class="org.springframework.http.client.SimpleClientHttpRequestFactory">
        <property name="readTimeout" value="10000"/>
        <property name="connectTimeout" value="5000"/>
    </bean>
    <bean id="simpleRestTemplate" class="org.springframework.web.client.RestTemplate">
        <constructor-arg ref="ky.requestFactory"/>
        <property name="messageConverters">
            <list>
                <bean class="org.springframework.http.converter.FormHttpMessageConverter"/>
                <bean class="org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter"/>
                <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>
                <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                    <property name="supportedMediaTypes">
                        <list>
                            <value>text/plain;charset=UTF-8</value>
                        </list>
                    </property>
                </bean>
            </list>
        </property>
    </bean>
</beans>

public RestTemplate() {
        this.messageConverters.add(new ByteArrayHttpMessageConverter());
        this.messageConverters.add(new StringHttpMessageConverter());
        this.messageConverters.add(new ResourceHttpMessageConverter());
        this.messageConverters.add(new SourceHttpMessageConverter<Source>());
        this.messageConverters.add(new AllEncompassingFormHttpMessageConverter());
        if (romePresent) {
            this.messageConverters.add(new AtomFeedHttpMessageConverter());
            this.messageConverters.add(new RssChannelHttpMessageConverter());
        }
        if (jaxb2Present) {
            this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
        }
        if (jackson2Present) {
            this.messageConverters.add(new MappingJackson2HttpMessageConverter());
        }
        else if (jacksonPresent) {
            this.messageConverters.add(new MappingJacksonHttpMessageConverter());
        }
    }

public class StringHttpMessageConverter extends AbstractHttpMessageConverter<String> {
    public static final Charset DEFAULT_CHARSET = Charset.forName("ISO-8859-1");
    private final Charset defaultCharset;
    private final List<Charset> availableCharsets;
    private boolean writeAcceptCharset = true;
    /**
     * A default constructor that uses {@code "ISO-8859-1"} as the default charset.
     * @see #StringHttpMessageConverter(Charset)
     */
    public StringHttpMessageConverter() {
        this(DEFAULT_CHARSET);
    }
    /**
     * A constructor accepting a default charset to use if the requested content
     * type does not specify one.
     */
    public StringHttpMessageConverter(Charset defaultCharset) {
        super(new MediaType("text", "plain", defaultCharset), MediaType.ALL);
        this.defaultCharset = defaultCharset;
        this.availableCharsets = new ArrayList<Charset>(Charset.availableCharsets().values());
    }
    /**
     * Indicates whether the {@code Accept-Charset} should be written to any outgoing request.
     * <p>Default is {@code true}.
     */
    public void setWriteAcceptCharset(boolean writeAcceptCharset) {
        this.writeAcceptCharset = writeAcceptCharset;
    }
    @Override
    public boolean supports(Class<?> clazz) {
        return String.class.equals(clazz);
    }
    @Override
    protected String readInternal(Class<? extends String> clazz, HttpInputMessage inputMessage) throws IOException {
        Charset charset = getContentTypeCharset(inputMessage.getHeaders().getContentType());
        return StreamUtils.copyToString(inputMessage.getBody(), charset);
    }
    @Override
    protected Long getContentLength(String s, MediaType contentType) {
        Charset charset = getContentTypeCharset(contentType);
        try {
            return (long) s.getBytes(charset.name()).length;
        }
        catch (UnsupportedEncodingException ex) {
            // should not occur
            throw new IllegalStateException(ex);
        }
    }
    @Override
    protected void writeInternal(String s, HttpOutputMessage outputMessage) throws IOException {
        if (this.writeAcceptCharset) {
            outputMessage.getHeaders().setAcceptCharset(getAcceptedCharsets());
        }
        Charset charset = getContentTypeCharset(outputMessage.getHeaders().getContentType());
        StreamUtils.copy(s, charset, outputMessage.getBody());
    }
    /**
     * Return the list of supported {@link Charset}.
     * <p>By default, returns {@link Charset#availableCharsets()}. Can be overridden in subclasses.
     * @return the list of accepted charsets
     */
    protected List<Charset> getAcceptedCharsets() {
        return this.availableCharsets;
    }
    private Charset getContentTypeCharset(MediaType contentType) {
        if (contentType != null && contentType.getCharSet() != null) {
            return contentType.getCharSet();
        }
        else {
            return this.defaultCharset;
        }
    }
}