SpringMVC - 04上傳檔案
阿新 • • 發佈：2020-11-22
SpringMVC - 04上傳檔案
（1）檔案上傳客戶端三要素
- 表單項 type = "file"
- 表單的提交方式是post
- 表單的enctype屬性是多部分表單形式，及enctype = "multipart/form-data"
<form action="${pageContext.request.contextPath}/user/quick22" method="post" enctype="multipart/form-data"> 名稱<input type="text" name="username"><br/> 檔案<input type="file" name="uploadFile"><br/> <input type="submit" value="提交"> </form>
（2）檔案上傳原理
> 當form表單修改為多部分表單時，request.getParameter()將失效。
> enctype="application/x-www-form-urlencoded"時，form表單的正文內容格式是：key=value&key=value&key=value。
> 當form表單的enctype取值為Multipart/form-data時，請求正文內容就變成多部分形式。
（3）檔案上傳
（3.1）單檔案上傳
> 匯入fileupload和io座標
<dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.3</version> </dependency> <dependency><groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version> </dependency>
>spring-mvc.xml配置檔案上傳解析器
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="defaultEncoding" value="UTF-8"/> // 上傳檔案的編碼型別 <property name="maxUploadSize" value="5000000"/> // 上傳檔案總大小 <property name="maxUploadSizePerFile" value="500000"/> // 上傳單個檔案的大小 </bean>
>檔案上傳程式碼
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Upload上傳檔案</title> </head> <body> <form action="${pageContext.request.contextPath}/user/quick22" method="post" enctype="multipart/form-data"> 名稱<input type="text" name="username"><br/> 檔案<input type="file" name="uploadFile"><br/> <input type="submit" value="提交"> </form> </body> </html>
@RequestMapping("/quick22")
@ResponseBody
public void save22(String username, MultipartFile uploadFile) throws IOException {
System.out.println(username);
String originalFilename = uploadFile.getOriginalFilename();
uploadFile.transferTo(new File("E:\\java\\" + originalFilename));
}
> 匯入包故障
Caused by: java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory ；未正常匯入jar包
（3.2）多檔案上傳，硬編碼
<form action="${pageContext.request.contextPath}/user/quick23" method="post" enctype="multipart/form-data"> 名稱<input type="text" name="username"><br/> 檔案<input type="file" name="uploadFile"><br/> 檔案2<input type="file" name="uploadFile2"><br/> <input type="submit" value="提交"> </form>
@RequestMapping("/quick22")
@ResponseBody
public void save22(String username, MultipartFile uploadFile,MultipartFile uploadFile2) throws IOException {
System.out.println(username);
String originalFilename = uploadFile.getOriginalFilename();
uploadFile.transferTo(new File("E:\\java\\" + originalFilename));
String originalFilename2 = uploadFile2.getOriginalFilename();
uploadFile2.transferTo(new File("E:\\java\\" + originalFilename2));
}
（3.3）多檔案上傳，陣列
@RequestMapping("/quick23")
@ResponseBody
public void save23(String username, MultipartFile[] uploadFile) throws IOException {
System.out.println(username);
for (MultipartFile file:uploadFile){
String originalFilename = file.getOriginalFilename();
file.transferTo(new File("E:\\java\\" + originalFilename));
}
}
<form action="${pageContext.request.contextPath}/user/quick23" method="post" enctype="multipart/form-data"> 名稱<input type="text" name="username"><br/> 檔案<input type="file" name="uploadFile"><br/> 檔案2<input type="file" name="uploadFile"><br/> 檔案3<input type="file" name="uploadFile"><br/> <input type="submit" value="提交"> </form>