spring boot實現圖片的上傳和下載功能
阿新 • • 發佈：2019-01-07
這篇部落格簡單介紹下spring boot下圖片上傳和下載，已經遇到的問題。首先需要建立一個spring boot專案。
1，核心的controller程式碼
package com.qwrt.station.websocket.controller; import com.alibaba.fastjson.JSONObject; import com.qwrt.station.common.util.JsonUtil; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Value; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.multipart.MultipartFile; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.*; /** * Created by jack on 2017/10/30. */ @RestController @RequestMapping("v1/uploadDownload") public class UploadDownloadController { private static final Logger logger = LoggerFactory.getLogger(UploadDownloadController.class); @Value("${uploadDir}") private String uploadDir; @RequestMapping(value = "/uploadImage", method = RequestMethod.POST) public JSONObject uploadImage(@RequestParam(value = "file") MultipartFile file) throws RuntimeException { if (file.isEmpty()) { return JsonUtil.getFailJsonObject("檔案不能為空"); } // 獲取檔名 String fileName = file.getOriginalFilename(); logger.info("上傳的檔名為：" + fileName); // 獲取檔案的字尾名 String suffixName = fileName.substring(fileName.lastIndexOf(".")); logger.info("上傳的字尾名為：" + suffixName); // 檔案上傳後的路徑 String filePath = uploadDir; // 解決中文問題，liunx下中文路徑，圖片顯示問題 // fileName = UUID.randomUUID() + suffixName; File dest = new File(filePath + fileName); // 檢測是否存在目錄 if (!dest.getParentFile().exists()) { dest.getParentFile().mkdirs(); } try { file.transferTo(dest); logger.info("上傳成功後的檔案路徑未：" + filePath + fileName); return JsonUtil.getSuccessJsonObject(fileName); } catch (IllegalStateException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return JsonUtil.getFailJsonObject("檔案上傳失敗"); } //檔案下載相關程式碼 @RequestMapping(value = "/downloadImage",method = RequestMethod.GET) public String downloadImage(String imageName,HttpServletRequest request, HttpServletResponse response) { //String fileName = "123.JPG"; logger.debug("the imageName is : "+imageName); String fileUrl = uploadDir+imageName; if (fileUrl != null) { //當前是從該工程的WEB-INF//File//下獲取檔案(該目錄可以在下面一行程式碼配置)然後下載到C:\\users\\downloads即本機的預設下載的目錄 /* String realPath = request.getServletContext().getRealPath( "//WEB-INF//");*/ /*File file = new File(realPath, fileName);*/ File file = new File(fileUrl); if (file.exists()) { response.setContentType("application/force-download");// 設定強制下載不開啟 response.addHeader("Content-Disposition", "attachment;fileName=" + imageName);// 設定檔名 byte[] buffer = new byte[1024]; FileInputStream fis = null; BufferedInputStream bis = null; try { fis = new FileInputStream(file); bis = new BufferedInputStream(fis); OutputStream os = response.getOutputStream(); int i = bis.read(buffer); while (i != -1) { os.write(buffer, 0, i); i = bis.read(buffer); } System.out.println("success"); } catch (Exception e) { e.printStackTrace(); } finally { if (bis != null) { try { bis.close(); } catch (IOException e) { e.printStackTrace(); } } if (fis != null) { try { fis.close(); } catch (IOException e) { e.printStackTrace(); } } } } } return null; } }
上面的程式碼有兩個方法，上面的方法是圖片上傳的方法，下面的方法是圖片下載的方法。下載圖片需要傳入圖片的檔名，在ios，android手機，谷歌瀏覽器測試，上傳下載沒有問題。
2，測試的html的核心程式碼如下，進行圖片的上傳和下載：
<!DOCTYPE html> <html> <head> <meta charset="UTF-8" /> <title>websocket chat</title> </head> <body> <div> <label>輸入資訊：</label><input id="id" width="100px" /><br /> <button id="btn">傳送訊息</button> <button id="connection">websocket連線</button> <button id="disconnection">斷開websocket連線</button> <br /><br /> <form enctype="multipart/form-data" id="uploadForm"> <input type="file" name="uploadFile" id="upload_file" style="margin-bottom:10px;"> <input type="button" id="uploadPicButton" value="上傳" onclick="uploadImage()"> </form> <!--<input type="file" onchange="uploadImgTest();" id="uploadImg" name="uploadImg" /> <button id="uploadImage" onclick="uploadImage();">上傳</button>--> </div> <div id="test"> </div> <hr color="blanchedalmond"/> <div id="voiceDiv"> </div> <hr color="chartreuse" /> <div id="imgDiv" style="width: 30%;height: 30%;"> <img src="http://192.168.9.123:8860/v1/uploadDownload/downloadImage?imageName=123.JPG" style="width: 160px;height: 160px;"/> </div> </body> <script src="js/jquery-3.2.1.min.js"></script> <!--<script th:src="@{stomp.min.js}"></script>--> <script src="js/sockjs.min.js"></script> <script> var websocketUrl = "ws://192.168.9.123:8860/webSocketServer"; var websocket; if('WebSocket' in window) { //websocket = new WebSocket("ws://" + document.location.host + "/webSocketServer"); //websocket = new WebSocket("ws://192.168.9.123:9092/webSocketServer"); //websocket = new WebSocket("ws://localhost:8860/webSocketServer"); websocket = new WebSocket(websocketUrl); } else if('MozWebSocket' in window) { websocket = new MozWebSocket("ws://" + document.location.host + "/webSocketServer"); } else { websocket = new SockJS("http://" + document.location.host + "/sockjs/webSocketServer"); } websocket.onopen = function(evnt) { console.log("onopen----", evnt.data); }; websocket.onmessage = function(evnt) { //$("#test").html("(<font color='red'>" + evnt.data + "</font>)"); console.log("onmessage----", evnt.data); //$("#test").html(evnt.data); $("#test").append('<div>' + event.data + '</div>'); }; websocket.onerror = function(evnt) { console.log("onerror----", evnt.data); } websocket.onclose = function(evnt) { console.log("onclose----", evnt.data); } $('#btn').on('click', function() { if(websocket.readyState == websocket.OPEN) { var msg = $('#id').val(); //呼叫後臺handleTextMessage方法 websocket.send(msg); } else { alert("連線失敗!"); } }); $('#disconnection').on('click', function() { if(websocket.readyState == websocket.OPEN) { websocket.close(); //websocket.onclose(); console.log("關閉websocket連線成功"); } }); $('#connection').on('click', function() { if(websocket.readyState == websocket.CLOSED) { websocket.open(); //websocket.onclose(); console.log("開啟websocket連線成功"); } }); //監聽視窗關閉事件，當視窗關閉時，主動去關閉websocket連線，防止連線還沒斷開就關閉視窗，server端會拋異常。 window.onbeforeunload = function() { websocket.close(); } function uploadImgTest() { } function uploadImage(){ //var uploadUrl = "http://localhost:8860/v1/uploadDownload/uploadImage"; var uploadUrl = "http://192.168.9.123:8860/v1/uploadDownload/uploadImage"; var downUrl = "http://192.168.9.123:8860/v1/uploadDownload/downloadImage" var pic = $('#upload_file')[0].files[0]; var fd = new FormData(); //fd.append('uploadFile', pic); fd.append('file', pic); $.ajax({ url:uploadUrl, type:"post", // Form資料 data: fd, cache: false, contentType: false, processData: false, success:function(data){ console.log("the data is : {}",data); if(data.code == 0){ console.log("上傳成功後的檔案路徑為："+data.data); var img = $("<img />") img.attr("src",downUrl+"?imageName="+data.data); img.width("160px"); img.height("160px"); $("#imgDiv").append(img); } } }); } </script> </html>
上面的程式碼有些和圖片的上傳和下載沒有關係，根據需要自己去掉，看圖片上傳和下載的核心程式碼，需要引入jquery。
3，spring boot的屬性配置：
1，解決圖片上傳太大的問題：
spring:http: multipart: max-file-size: 100Mb #檔案上傳大小 max-request-size: 200Mb #最打請求大小
spring:
http:
multipart:
max-file-size: 100Mb #檔案上傳大小
max-request-size: 200Mb #最打請求大小
這是新版spring boot解決圖片或者檔案上傳太大的問題，老闆的不是這樣解決的。可以自己查資料
2,配置檔案上傳儲存的位置：
#上傳位置
uploadDir: F:\mystudy\pic\
spring boot多檔案上傳：
核心程式碼：
/**
* 多檔案上傳
* @param files
* @return
* @throws RuntimeException
*/
@RequestMapping(value = "/uploadFiles", method = RequestMethod.POST)
public JSONObject uploadFiles(@RequestParam(value = "file") MultipartFile[] files){
StringBuffer result = new StringBuffer();
try {
for (int i = 0; i < files.length; i++) {
if (files[i] != null) {
//呼叫上傳方法
String fileName = executeUpload(files[i]);
result.append(fileName+";");
}
}
} catch (Exception e) {
e.printStackTrace();
JsonUtil.getFailJsonObject("檔案上傳失敗");
}
return JsonUtil.getSuccessJsonObject(result.toString());
}
/**
* 提取上傳方法為公共方法
* @param file
* @return
* @throws Exception
*/
private String executeUpload(MultipartFile file)throws Exception{
//檔案字尾名
String suffix = file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf("."));
//上傳檔名
String fileName = UUID.randomUUID()+suffix;
//服務端儲存的檔案物件
File serverFile = new File(uploadDir + fileName);
// 檢測是否存在目錄
if (!serverFile.getParentFile().exists()) {
serverFile.getParentFile().mkdirs();
}
//將上傳的檔案寫入到伺服器端檔案內
file.transferTo(serverFile);
return fileName;
}