java web图片上传和文件上传实例

来源：互联网发布：小米数据迁移苹果编辑：程序博客网时间：2024/06/08 08:29

图片上传和文件上传本质上是一样的，图片本身也是文件。文件上传就是将图片上传到服务器，方式虽然有很多，但底层的实现都是文件的读写操作。

注意事项

1.form表单一定要写属性enctype="multipart/form-data"

2.为了能保证文件能上传成功file控件的name属性值要和你提交的控制层变量名一致，

例如空间名是file那么你要在后台这样定义

?
1
2
3
4
5
private File file; //file控件名
 
private String fileContentType;//图片类型
 
private String fileFileName; //文件名

1.jsp页面

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
<%@ 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>文件上传</title>
</head>
<body>
<form method="post"action="" enctype="multipart/form-data">
<input type="file"name="file" value="file">
<input type="submit"value="确定">
</form>
</body>
</html>

1.页面数据需要提交的Controller

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
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 extendsActionSupport {
  /**
   *
   */
  privatestatic final long serialVersionUID = 1L;
  @Resource(name="lunboBiz")
  privateLunboBiz lunboBiz;
  privateImage image;
  privateFile file; //file控件名
  privateString fileContentType;//图片类型
  privateString fileFileName; //文件名
  privateInteger number;
   
  publicString findImage(){
    image=lunboBiz.findImage();
    returnSUCCESS;
  }
   
  publicString alterImage(){
    image=lunboBiz.findImage();
    returnSUCCESS;
  }
   
  publicString alterImage1(){
    HttpServletRequest request = ServletActionContext.getRequest();
    String root = request.getRealPath("/upload");//图片要上传到的服务器路径
    String names[]=fileFileName.split("\\.");
    String fileName="";
    if(names.length>=1){
      fileName=getRandomString(20)+"."+names[names.length-1];
    }
    String picPath="upload/"+fileName;//图片保存到数据库的路径
    File file1=newFile(root);
    try{
      FileUtils.copyFile(file,new File(file1,fileName));
      }
    }catch (IOException e) {
      e.printStackTrace();
    }
    returnSUCCESS;
  }
   
  /*获取一条随机字符串*/
  publicString getRandomString(intlength) { //length表示生成字符串的长度
    String base ="abcdefghijklmnopqrstuvwxyz0123456789";  
    Random random =new Random();  
    StringBuffer sb =new StringBuffer();  
    for(int i = 0; i < length; i++) {  
      intnumber = random.nextInt(base.length());   
      sb.append(base.charAt(number));  
    }  
    returnsb.toString();   
   } 
 
}

这是通过复制的方式上传文件，还有其他方式

方法二

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
@Controller("contractAction")
public class ContractAction extends ActionSupport {
   
  private final static String UPLOADDIR ="/files";//文件上传的路径，在webContent下建立
  private File file;//input控件名一定为file 
  //上传文件名集合 
  private String fileFileName; 
  //上传文件内容类型集合 
  private String fileContentType;
   
  private String filename;
  
  public String upload() throws FileNotFoundException, IOException{
    String path=uploadFile();//文件保存数据库的路径
   
    returnSUCCESS;
  }
   
  //执行上传功能 
  @SuppressWarnings("deprecation")
  public String uploadFile() throws FileNotFoundException, IOException { 
    try{  
      InputStreamin = newFileInputStream(file);  
      String dir = ServletActionContext.getRequest().getRealPath(UPLOADDIR);
      File fileLocation =new File(dir); 
      //此处也可以在应用根目录手动建立目标上传目录
      if(!fileLocation.exists()){
        boolean isCreated = fileLocation.mkdir();
        if(!isCreated) {
          //目标上传目录创建失败,可做其他处理,例如抛出自定义异常等,一般应该不会出现这种情况。
          returnnull; 
        }
      }
      // 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(); 
      returnUPLOADDIR.substring(1)+"\\"+fileFileName;
      }catch (FileNotFoundException ex) {
        returnnull;  
      }catch (IOException ex) {
        returnnull;  
    } 
  }
   
   
  public static String getRandomString(int length){
    String str="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
    Random random=newRandom();
    StringBuffer sb=newStringBuffer();
    for(int i=0;i<length;i++){
     int number=random.nextInt(62);
     sb.append(str.charAt(number));
    }
    returnsb.toString();
  } 
 
}

除了单图上传还有多图上传，原理都是一样的

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
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;
 
 
/**
 * 多文件上传
 */
public class FilesUploadAction extends ActionSupport {
     //上传文件存放路径 
     private final static String UPLOADDIR ="/upload";  
     //上传文件集合 
     private List<File> file; 
     //上传文件名集合 
     private List<String> fileFileName; 
     //上传文件内容类型集合 
     private List<String> fileContentType; 
      
     public List<File> getFile() { 
       returnfile;  
     } 
  
     public void setFile(List<File> file) { 
       this.file = file; 
     } 
  
    public List<String> getFileFileName() { 
      returnfileFileName;  
    } 
  
     public void setFileFileName(List<String> fileFileName) { 
       this.fileFileName = fileFileName; 
     } 
  
     public List<String> getFileContentType() { 
       returnfileContentType;  
     } 
  
     public void setFileContentType(List<String> fileContentType) { 
       this.fileContentType = fileContentType; 
     } 
  
      
     public String uploadform() throws Exception {
       HttpServletRequest request = ServletActionContext.getRequest();
       String webpath=null;//上传路径
       for(int i = 0; i < file.size(); i++) {  
         //循环上传每个文件 
         uploadFile(i);
         webpath="upload/"+this.getFileFileName().get(i);
       }
       return"SUCCESS";
     }
    
  
     
    //执行上传功能 
     private String uploadFile(int i) throws FileNotFoundException, IOException { 
       try{  
          
         InputStreamin = newFileInputStream(file.get(i));  
         String dir = ServletActionContext.getRequest().getRealPath(UPLOADDIR);
         File fileLocation =new File(dir); 
         //此处也可以在应用根目录手动建立目标上传目录
         if(!fileLocation.exists()){
           boolean isCreated = fileLocation.mkdir();
           if(!isCreated) {
             //目标上传目录创建失败,可做其他处理,例如抛出自定义异常等,一般应该不会出现这种情况。
             returnnull; 
           }
         }
         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(); 
         returnuploadFile.toString();
       }catch (FileNotFoundException ex) {
         returnnull;  
       }catch (IOException ex) {
         returnnull;  
       } 
     }
   }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。

原文链接：http://www.cnblogs.com/bunuo/p/upLoadFile.html

阅读全文

0 0