如何在spring boot中使用rest模板来使用多部分表单数据

<dependencies>
    <!-- Spring Web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- Apache HttpClient -->
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
    </dependency>
</dependencies>

MultiValueMap<String, Object> parts = new LinkedMultiValueMap<>();
parts.add("field1", "value1");
parts.add("field2", "value2");
parts.add("file", new FileSystemResource("path/to/file.txt"));

HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);

HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(parts, headers);

RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> response = restTemplate.postForEntity("http://example.com/upload", requestEntity, String.class);