springboot/springmvc上傳檔案（CommonsMultipartResolver）
上一篇博文講到了（Servlet3.0支援）的檔案上傳：https://blog.csdn.net/frozenpower/article/details/81141297
這篇我們來看可配置的檔案上傳解析器CommonsMultipartResolver
CommonsMultipartResolver也實現了MultipartResolver。那我們看它的關鍵兩個函式isMultipart和resolveMultipart
public boolean isMultipart(HttpServletRequest request) {
return ServletFileUpload.isMultipartContent(request);
}
public MultipartHttpServletRequest resolveMultipart(final HttpServletRequest request) throws MultipartException {
Assert.notNull(request, "Request must not be null");
if (this.resolveLazily) {
return new DefaultMultipartHttpServletRequest(request) {
protected void initializeMultipart() {
MultipartParsingResult parsingResult = CommonsMultipartResolver.this.parseRequest(request);
this.setMultipartFiles(parsingResult.getMultipartFiles());
this.setMultipartParameters(parsingResult.getMultipartParameters());
this.setMultipartParameterContentTypes(parsingResult.getMultipartParameterContentTypes());
}
};
} else {
MultipartParsingResult parsingResult = this.parseRequest(request);
return new DefaultMultipartHttpServletRequest(request, parsingResult.getMultipartFiles(), parsingResult.getMultipartParameters(), parsingResult.getMultipartParameterContentTypes());
}
}
protected MultipartParsingResult parseRequest(HttpServletRequest request) throws MultipartException {
String encoding = this.determineEncoding(request);
FileUpload fileUpload = this.prepareFileUpload(encoding);
try {
List<FileItem> fileItems = ((ServletFileUpload)fileUpload).parseRequest(request);
return this.parseFileItems(fileItems, encoding);
} catch (SizeLimitExceededException var5) {
throw new MaxUploadSizeExceededException(fileUpload.getSizeMax(), var5);
} catch (FileSizeLimitExceededException var6) {
throw new MaxUploadSizeExceededException(fileUpload.getFileSizeMax(), var6);
} catch (FileUploadException var7) {
throw new MultipartException("Failed to parse multipart servlet request", var7);
}
}
邏輯也不難
在使用的時候，首先要新增相關jar
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2.2</version>
</dependency>
配置multipartResolver解析器，替換原來預設的
<!-- 定義檔案上傳解析器 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 設定預設編碼 -->
<property name="defaultEncoding" value="UTF-8"></property>
<!-- 設定檔案上傳的最大值為5MB，5*1024*1024 -->
<property name="maxUploadSize" value="5242880"></property>
<!-- 設定檔案上傳時寫入記憶體的最大值，如果小於這個引數不會生成臨時檔案，預設為10240 -->
<property name="maxInMemorySize" value="40960"></property>
<!-- 上傳檔案的臨時路徑 -->
<property name="uploadTempDir" value="fileUpload/temp"></property>
<!-- 延遲檔案解析 -->
<property name="resolveLazily" value="true"/>
</bean>
這兩天發現了一個坑，還需要配置個轉換器
@Configuration
@EnableWebMvc
public class MVCConfiguration extends WebMvcConfigurerAdapter {
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
super.configureMessageConverters(converters);
// 初始化轉換器
FastJsonHttpMessageConverter fastConvert = new FastJsonHttpMessageConverter();
// 初始化一個轉換器配置
FastJsonConfig fastJsonConfig = new FastJsonConfig();
fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat);
// 將配置設定給轉換器並新增到HttpMessageConverter轉換器列表中
fastConvert.setFastJsonConfig(fastJsonConfig);
List<MediaType> supportedMediaTypes = new ArrayList<>();
supportedMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
fastConvert.setSupportedMediaTypes(supportedMediaTypes);
converters.add(fastConvert);
}
}
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作者：frozenpower
來源：CSDN
原文：https://blog.csdn.net/frozenpower/article/details/81142034
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