java 的 Map<String,Object> 转 MultiValueMap<String,String>

可以使用Spring框架中的MultiValueMapConverter进行转换。具体实现代码如下：

import org.springframework.core.convert.converter.Converter;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;

import java.util.Map;

public class MapToMultiValueMapConverter implements Converter<Map<String, Object>, MultiValueMap<String, String>> {

    @Override
    public MultiValueMap<String, String> convert(Map<String, Object> source) {
        MultiValueMap<String, String> result = new LinkedMultiValueMap<>();
        for (Map.Entry<String, Object> entry : source.entrySet()) {
            String key = entry.getKey();
            Object value = entry.getValue();
            if (value instanceof String) {
                result.add(key, (String) value);
            } else if (value instanceof String[]) {
                String[] values = (String[]) value;
                for (String v : values) {
                    result.add(key, v);
                }
            } else if (value instanceof Iterable) {
                Iterable iterable = (Iterable) value;
                for (Object v : iterable) {
                    result.add(key, String.valueOf(v));
                }
            } else {
                result.add(key, String.valueOf(value));
            }
        }
        return result;
    }
}

使用方式如下：

Map<String, Object> map = new HashMap<>();
map.put("name", "张三");
map.put("age", 18);
map.put("hobbies", new String[]{"reading", "swimming"});
map.put("favorite_books", Arrays.asList("Java编程思想", "Effective Java"));

MultiValueMap<String, String> multiValueMap = new MapToMultiValueMapConverter().convert(map);

这样就可以将Map对象转换为MultiValueMap对象了。