SpringBoot 文件上传与下载

佚名 6年前 (2019-05-15) 随笔 1673人围观抢沙发百度已收录

1. 上传文件大小限制的配置

　现象：文件上传过大时报FileUploadBase$SizeLimitExceededException异常

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Caused by: org.apache.tomcat.util.http.fileupload.FileUploadBase$SizeLimitExceededException: the request was rejected because its size (336738104) exceeds the configured maximum (10485760)
    at org.apache.tomcat.util.http.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:805)
    at org.apache.tomcat.util.http.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:256)
    at org.apache.tomcat.util.http.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:280)
    at org.apache.catalina.connector.Request.parseParts(Request.java:2869)
    ... 31 more

原因：springboot内置tomact的的文件传输默认为1MB

@ConfigurationProperties(
    prefix = "spring.http.multipart",
    ignoreUnknownFields = false
)
public class MultipartProperties {
    private boolean enabled = true;
    private String location;
    private String maxFileSize = "1MB";
    private String maxRequestSize = "10MB";
    private String fileSizeThreshold = "0";
    private boolean resolveLazily = false;

    public MultipartProperties() {
    }
    
    ...
}

解决方式：

第一种：在application.properties文件中配置，注意MB是大写，也可以换成KB单位

spring.http.multipart.enabled=true
spring.http.multipart.max-file-size=100MB
spring.http.multipart.max-request-size=100MB

第二种：java代码配置，这个配置会覆盖配置文件(第一种)中属性的配置，还有若是不设置文件和请求大小，默认无穷大

    @Bean
    public MultipartConfigElement multipartConfigElement() {
        MultipartConfigFactory factory = new MultipartConfigFactory();
        // 文件上传大小
        factory.setMaxFileSize("500MB");
        // 请求上传大小
        factory.setMaxRequestSize("500MB");

        return factory.createMultipartConfig();
    }

注意：全局异常捕捉，无法正确返回给前端提示。