本篇文章介绍springboot的上传和下载功能。
一、创建springboot工程，添加依赖
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compile("org.springframework.boot:spring-boot-starter-web") compile("org.springframework.boot:spring-boot-starter-thymeleaf") |
工程目录为：
application.java 启动类
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package hello; import org.springframework.boot.springapplication; import org.springframework.boot.autoconfigure.springbootapplication; import org.springframework.boot.context.properties.enableconfigurationproperties; @springbootapplicationpublic class application { public static void main(string[] args) { springapplication.run(application.class, args); } } |
二、创建测试页面
在resources/templates目录下新建uploadform.html
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<html xmlns:th="http://www.thymeleaf.org"> <body> <div th:if="${message}"> <h2 th:text="${message}"/> </div> <div> <form method="post" enctype="multipart/form-data" action="/"> <table> <tr><td>file to upload:</td><td><input type="file" name="file" /></td></tr> <tr><td></td><td><input type="submit" value="upload" /></td></tr> </table> </form> </div> <div> <ul> <li th:each="file : ${files}"> <a th:href="${file}" rel="external nofollow" th:text="${file}" /> </li> </ul> </div> </body> </html> |
三、新建storageservice服务
storageservice接口
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package hello.storage; import org.springframework.core.io.resource; import org.springframework.web.multipart.multipartfile; import java.nio.file.path; import java.util.stream.stream; public interface storageservice { void init(); void store(multipartfile file); stream<path> loadall(); path load(string filename); resource loadasresource(string filename); void deleteall(); } |
storageservice实现
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package hello.storage; import org.springframework.core.io.resource; import org.springframework.core.io.urlresource; import org.springframework.stereotype.service; import org.springframework.util.filesystemutils; import org.springframework.util.stringutils; import org.springframework.web.multipart.multipartfile; import java.io.ioexception; import java.net.malformedurlexception; import java.nio.file.files; import java.nio.file.path; import java.nio.file.paths; import java.nio.file.standardcopyoption; import java.util.function.predicate; import java.util.stream.stream; @servicepublic class filesystemstorageservice implements storageservice { private final path rootlocation = paths.get("upload-dir"); /** * 保存文件 * * @param file 文件 */ @override public void store(multipartfile file) { string filename = stringutils.cleanpath(file.getoriginalfilename()); try { if (file.isempty()) { throw new storageexception("failed to store empty file " + filename); } if (filename.contains("..")) { // this is a security check throw new storageexception("cannot store file with relative path outside current directory " + filename); } files.copy(file.getinputstream(), this.rootlocation.resolve(filename), standardcopyoption.replace_existing); } catch (ioexception e) { throw new storageexception("failed to store file " + filename, e); } } /** * 列出upload-dir下面所有文件 * @return */ @override public stream<path> loadall() { try { return files.walk(this.rootlocation, 1) //path -> !path.equals(this.rootlocation) .filter(new predicate<path>() { @override public boolean test(path path) { return !path.equals(rootlocation); } }); } catch (ioexception e) { throw new storageexception("failed to read stored files", e); } } @override public path load(string filename) { return rootlocation.resolve(filename); } /** * 获取文件资源 * @param filename 文件名 * @return resource */ @override public resource loadasresource(string filename) { try { path file = load(filename); resource resource = new urlresource(file.touri()); if (resource.exists() || resource.isreadable()) { return resource; } else { throw new storagefilenotfoundexception("could not read file: " + filename); } } catch (malformedurlexception e) { throw new storagefilenotfoundexception("could not read file: " + filename, e); } } /** * 删除upload-dir目录所有文件 */ @override public void deleteall() { filesystemutils.deleterecursively(rootlocation.tofile()); } /** * 初始化 */ @override public void init() { try { files.createdirectories(rootlocation); } catch (ioexception e) { throw new storageexception("could not initialize storage", e); } } } |
storageexception.java
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package hello.storage; public class storageexception extends runtimeexception { public storageexception(string message) { super(message); } public storageexception(string message, throwable cause) { super(message, cause); } } storagefilenotfoundexception.javapackage hello.storage; public class storagefilenotfoundexception extends storageexception { public storagefilenotfoundexception(string message) { super(message); } public storagefilenotfoundexception(string message, throwable cause) { super(message, cause); } } |
四、controller创建
将上传的文件，放到工程的upload-dir目录，默认在界面上列出可以下载的文件。
listuploadedfiles函数，会列出当前目录下的所有文件
servefile下载文件
handlefileupload上传文件
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package hello; import java.io.ioexception; import java.util.stream.collectors; import org.springframework.beans.factory.annotation.autowired; import org.springframework.core.io.resource; import org.springframework.http.httpheaders; import org.springframework.http.responseentity; import org.springframework.stereotype.controller; import org.springframework.ui.model; import org.springframework.web.bind.annotation.exceptionhandler; import org.springframework.web.bind.annotation.getmapping; import org.springframework.web.bind.annotation.pathvariable; import org.springframework.web.bind.annotation.postmapping; import org.springframework.web.bind.annotation.requestparam; import org.springframework.web.bind.annotation.responsebody; import org.springframework.web.multipart.multipartfile; import org.springframework.web.servlet.mvc.method.annotation.mvcuricomponentsbuilder; import org.springframework.web.servlet.mvc.support.redirectattributes; import hello.storage.storagefilenotfoundexception; import hello.storage.storageservice; @controllerpublic class fileuploadcontroller { private final storageservice storageservice; @autowired public fileuploadcontroller(storageservice storageservice) { this.storageservice = storageservice; } @getmapping("/") public string listuploadedfiles(model model) throws ioexception { model.addattribute("files", storageservice.loadall().map( path -> mvcuricomponentsbuilder.frommethodname(fileuploadcontroller.class, "servefile", path.getfilename().tostring()).build().tostring()) .collect(collectors.tolist())); return "uploadform"; } @getmapping("/files/{filename:.+}") @responsebody public responseentity<resource> servefile(@pathvariable string filename) { resource file = storageservice.loadasresource(filename); return responseentity.ok().header(httpheaders.content_disposition, "attachment; filename=\"" + file.getfilename() + "\"").body(file); } @postmapping("/") public string handlefileupload(@requestparam("file") multipartfile file, redirectattributes redirectattributes) { storageservice.store(file); redirectattributes.addflashattribute("message", "you successfully uploaded " + file.getoriginalfilename() + "!"); return "redirect:/"; } @exceptionhandler(storagefilenotfoundexception.class) public responseentity<?> handlestoragefilenotfound(storagefilenotfoundexception exc) { return responseentity.notfound().build(); } } |
源码下载：https://github.com/hellokittynii/springboot/tree/master/springbootuploadanddownload
总结
以上所述是小编给大家介绍的springboot 文件上传和下载的实现源码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持！
原文链接：https://blog.csdn.net/u010889616/article/details/79764175
