SpringBoot上传相关配置

@ConfigurationProperties(prefix = "spring.http.multipart", ignoreUnknownFields = false)
public class MultipartProperties {
    /**
     * Enable support of multi-part uploads.
     * 默认使用multi-part的上传
     */
    private boolean enabled = true;
    /**
     * Intermediate location of uploaded files.
     */
    //上传的临时目录
    private String location;
    /**
     * Max file size. Values can use the suffixed "MB" or "KB" to indicate a Megabyte or
     * Kilobyte size.
     */
    private String maxFileSize = "1Mb";
    /**
     * Max request size. Values can use the suffixed "MB" or "KB" to indicate a Megabyte
     * or Kilobyte size.
     */
    private String maxRequestSize = "10Mb";
    /**
     * Threshold after which files will be written to disk. Values can use the suffixed
     * "MB" or "KB" to indicate a Megabyte or Kilobyte size.
     */
    private String fileSizeThreshold = "0";
    /**
     * Whether to resolve the multipart request lazily at the time of file or parameter
     * access.
     */
    private boolean resolveLazily = false;
    
    //省略setting和getting方法
    /**
     * Create a new {@link MultipartConfigElement} using the properties.
     * @return a new {@link MultipartConfigElement} configured using there properties
     */
    public MultipartConfigElement createMultipartConfig() {
        MultipartConfigFactory factory = new MultipartConfigFactory();
        if (StringUtils.hasText(this.fileSizeThreshold)) {
            factory.setFileSizeThreshold(this.fileSizeThreshold);
        }
        if (StringUtils.hasText(this.location)) {
            factory.setLocation(this.location);
        }
        if (StringUtils.hasText(this.maxRequestSize)) {
            factory.setMaxRequestSize(this.maxRequestSize);
        }
        if (StringUtils.hasText(this.maxFileSize)) {
            factory.setMaxFileSize(this.maxFileSize);
        }
        return factory.createMultipartConfig();
    }

/**
 * Factory that can be used to create a {@link MultipartConfigElement}. Size values can be
 * set using traditional {@literal long} values which are set in bytes or using more
 * readable {@literal String} variants that accept KB or MB suffixes, for example:
 * 就是处理传统配置的KB与MB的转换，其他的并没什么。主要是是最后都是kb
    
 * <pre class="code">
 * factory.setMaxFileSize(&quot;10Mb&quot;);
 * factory.setMaxRequestSize(&quot;100Kb&quot;);
 * </pre>
 *
 * @author Phillip Webb
 * @since 1.4.0
 */
public class MultipartConfigFactory {
    private String location;
    private long maxFileSize = -1;
    private long maxRequestSize = -1;
    private int fileSizeThreshold = 0;
    
    //省略 setting和getting
    /**
     * Create a new {@link MultipartConfigElement} instance.
     * @return the multipart config element
     */
    public MultipartConfigElement createMultipartConfig() {
        return new MultipartConfigElement(this.location, this.maxFileSize,
                this.maxRequestSize, this.fileSizeThreshold);
    }
}