java web圖片上傳和文件上傳
圖片上傳和文件上傳本質上是一樣的，圖片本身也是文件。文件上傳就是將圖片上傳到服務器，方式雖然有很多，但底層的實現都是文件的讀寫操作。
注意事項
1.form表單一定要寫屬性enctype="multipart/form-data"
2.為了能保證文件能上傳成功file控件的name屬性值要和你提交的控制層變量名一致，
例如空間名是file那麼你要在後台這樣定義
private File file; //file控件名
private String fileContentType;//圖片類型
private String fileFileName; //文件名
1.jsp頁面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta http-equiv="pragma" content="no-cache" /> <base target="_self"> <title>文件上傳</title> </head><body><form method="post" action="" enctype="multipart/form-data"><input type="file" name="file" value="file"><input type="submit" value="確定"></form></body></html>
1.頁面數據需要提交的Controller
package com.cpsec.tang.chemical.action;import java.io.File;import java.io.IOException;import java.util.Random;import javax.annotation.Resource;import javax.servlet.http.HttpServletRequest;import org.apache.commons.io.FileUtils;import org.apache.struts2.ServletActionContext;import org.springframework.stereotype.Controller;import com.cpsec.tang.chemical.biz.LunboBiz;import com.cpsec.tang.chemical.entity.Image;import com.opensymphony.xwork2.ActionSupport;@Controller("lunboAction")public class LunboAction extends ActionSupport { /** * */ private static final long serialVersionUID = 1L; @Resource(name="lunboBiz") private LunboBiz lunboBiz; private Image image; private File file; //file控件名private String fileContentType;//圖片類型private String fileFileName; //文件名private Integer number; public String findImage(){ image=lunboBiz.findImage(); return SUCCESS; } public String alterImage(){ image=lunboBiz.findImage(); return SUCCESS; } public String alterImage1(){ HttpServletRequest request = ServletActionContext.getRequest(); String root = request.getRealPath("/upload");//圖片要上傳到的服務器路徑String names[]=fileFileName.split("//."); String fileName=""; if(names.length>=1){ fileName=getRandomString(20)+"."+names[names.length-1]; } String picPath="upload/"+fileName;//圖片保存到數據庫的路徑File file1=new File(root); try { FileUtils.copyFile(file, new File(file1,fileName)); } } catch (IOException e) { e.printStackTrace(); } return SUCCESS; } /*獲取一條隨機字符串*/ public String getRandomString(int length) { //length表示生成字符串的長度String base = "abcdefghijklmnopqrstuvwxyz0123456789"; Random random = new Random(); StringBuffer sb = new StringBuffer(); for (int i = 0; i < length; i++) { int number = random.nextInt(base.length()); sb.append(base.charAt(number)); } return sb.toString(); } }這是通過複製的方式上傳文件，還有其他方式
方法二
@Controller("contractAction")public class ContractAction extends ActionSupport { private final static String UPLOADDIR = "/files";//文件上傳的路徑，在webContent下建立private File file; //input控件名一定為file //上傳文件名集合private String fileFileName; //上傳文件內容類型集合private String fileContentType; private String filename; public String upload() throws FileNotFoundException, IOException{ String path=uploadFile();//文件保存數據庫的路徑return SUCCESS; } //執行上傳功能@SuppressWarnings("deprecation") public String uploadFile() throws FileNotFoundException, IOException { try { InputStream in = new FileInputStream(file); String dir = ServletActionContext.getRequest().getRealPath(UPLOADDIR); File fileLocation = new File(dir); //此處也可以在應用根目錄手動建立目標上傳目錄if(!fileLocation.exists()){ boolean isCreated = fileLocation.mkdir(); if(!isCreated) { //目標上傳目錄創建失敗,可做其他處理,例如拋出自定義異常等,一般應該不會出現這種情況。 return null; } } // this.setFileFileName(getRandomString(20)); String[] Name=this.getFileFileName().split("//."); String fileName=getRandomString(20)+"."+Name[Name.length-1]; this.setFileFileName(fileName); System.out.println(fileName); File uploadFile = new File(dir, fileName); OutputStream out = new FileOutputStream(uploadFile); byte[] buffer = new byte[1024 * 1024]; int length; while ((length = in.read(buffer)) > 0) { out.write(buffer, 0, length); } in.close(); out.close(); return UPLOADDIR.substring(1)+"//"+fileFileName; } catch (FileNotFoundException ex) { return null; } catch (IOException ex) { return null; } } public static String getRandomString(int length){ String str="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; Random random=new Random(); StringBuffer sb=new StringBuffer(); for(int i=0;i<length;i++){ int number=random.nextInt(62); sb.append(str.charAt(number)); } return sb.toString(); } }除了單圖上傳還有多圖上傳，原理都是一樣的
package com.cpsec.tang.chemical.action;import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream;import java.util.List;import javax.servlet.http.HttpServletRequest;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;/** * 多文件上傳*/public class FilesUploadAction extends ActionSupport { //上傳文件存放路徑private final static String UPLOADDIR = "/upload"; //上傳文件集合private List<File> file; //上傳文件名集合private List<String> fileFileName; //上傳文件內容類型集合private List<String> fileContentType; public List<File> getFile() { return file; } public void setFile(List<File> file) { this.file = file; } public List<String> getFileFileName() { return fileFileName; } public void setFileFileName(List<String> fileFileName) { this.fileFileName = fileFileName; } public List<String> getFileContentType() { return fileContentType; } public void setFileContentType(List<String> fileContentType) { this.fileContentType = fileContentType; } public String uploadform() throws Exception { HttpServletRequest request = ServletActionContext.getRequest(); String webpath=null;//上傳路徑for (int i = 0; i < file.size(); i++) { //循環上傳每個文件uploadFile(i); webpath="upload/"+this.getFileFileName().get(i); } return "SUCCESS"; } //執行上傳功能private String uploadFile(int i) throws FileNotFoundException, IOException { try { InputStream in = new FileInputStream(file.get(i)); String dir = ServletActionContext.getRequest().getRealPath(UPLOADDIR); File fileLocation = new File(dir); //此處也可以在應用根目錄手動建立目標上傳目錄if(!fileLocation.exists()){ boolean isCreated = fileLocation.mkdir(); if(!isCreated) { //目標上傳目錄創建失敗,可做其他處理,例如拋出自定義異常等,一般應該不會出現這種情況。 return null; } } String fileName=this.getFileFileName().get(i); File uploadFile = new File(dir, fileName); OutputStream out = new FileOutputStream(uploadFile); byte[] buffer = new byte[1024 * 1024]; int length; while ((length = in.read(buffer)) > 0) { out.write(buffer, 0, length); } in.close(); out.close(); return uploadFile.toString(); } catch (FileNotFoundException ex) { return null; } catch (IOException ex) { return null; } } }感謝閱讀，希望能幫助到大家，謝謝大家對本站的支持！