文件上传功能的实现1(采用自编写的JavaBean组件)

来源：互联网发布：阶梯外圆数控车编程编辑：程序博客网时间：2024/06/11 09:41

1.package org.tjitcast.demo;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.ServletInputStream;
import java.util.Hashtable;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

public class FileUploadBean {
private String savePath;
private String filepath;
private String filename;
private String contentType;
private Hashtable<String, String> fields;

// 返回filename私有域的值
public String getFilename() {
return filename;
}

// 返回filepath私有域的值
public String getFilepath() {
return filepath;
}

// 返回savePath私有域的值
public void setSavePath(String savePath) {
this.savePath = savePath;
}

// 返回contentType私有域的值
public String getContentType() {
return contentType;
}

// 返回HTML表单中指定输入元素的值，元素的名字通过fieldName参数指定
public String getFieldValue(String fieldName) {
if (fields == null || fieldName == null)
return null;
return (String) fields.get(fieldName);
}

private void setFilename(String s) {
if (s == null)
return;

int pos = s.indexOf("filename=\"");
if (pos != -1) {
filepath = s.substring(pos + 10, s.length() - 1);
// Windows浏览器发送完整的文件路径和名字
// 但Linux/Unix和Mad浏览器只发送文件名字
pos = filepath.lastIndexOf("\\");
if (pos != -1)
filename = filepath.substring(pos + 1);
else
filename = filepath;
}
}

private void setContentType(String s) {
if (s == null)
return;

int pos = s.indexOf(": ");
if (pos != -1)
contentType = s.substring(pos + 2, s.length());
}

public void doUpload(HttpServletRequest request) throws IOException {
ServletInputStream in = request.getInputStream();
// 创建字节数组充当缓冲容器的作用
byte[] line = new byte[128];
int i = in.readLine(line, 0, 128);
if (i < 3)
return;
// -2丢弃换行字符
int boundaryLength = i - 2;
String boundary = new String(line, 0, boundaryLength);

fields = new Hashtable<String, String>();
while (i != -1) {
String newLine = new String(line, 0, i);
if (newLine.startsWith("Content-Disposition: form-data; name=\"")) {
if (newLine.indexOf("filename=\"") != -1) {
setFilename(new String(line, 0, i - 2));
if (filename == null)
return;
// 文件内容
i = in.readLine(line, 0, 128);
setContentType(new String(line, 0, i - 2));
i = in.readLine(line, 0, 128);
// 空行
newLine = new String(line, 0, i);
PrintWriter pw = new PrintWriter(new BufferedWriter(
new FileWriter((savePath == null ? "" : savePath)
+ filename)));
while (i != -1 && !newLine.startsWith(boundary)) {
// 文件内容的最后一行包含换行字符
// 因此必须检查当前行是否是最后一行
i = in.readLine(line, 0, 128);
if ((i == boundaryLength + 2 || i == boundaryLength + 4)
&& (new String(line, 0, i).startsWith(boundary)))
pw.print(newLine.substring(0, newLine.length() - 2));
else
pw.print(newLine);
newLine = new String(line, 0, i);
}
pw.close();
} else {
// 普通表单输入元素
// 获取输入元素名字
int pos = newLine.indexOf("name=\"");
String fieldName = newLine.substring(pos + 6, newLine
.length() - 3);
i = in.readLine(line, 0, 128);
newLine = new String(line, 0, i);
StringBuffer fieldValue = new StringBuffer(128);
while (i != -1 && !newLine.startsWith(boundary)) {
// 最后一行包含换行字符
// 因此必须检查当前行是否是最后一行
i = in.readLine(line, 0, 128);
if ((i == boundaryLength + 2 || i == boundaryLength + 4)
&& (new String(line, 0, i).startsWith(boundary)))
fieldValue.append(newLine.substring(0, newLine
.length() - 2));
else
fieldValue.append(newLine);
newLine = new String(line, 0, i);
}
fields.put(fieldName, fieldValue.toString());
}
}
i = in.readLine(line, 0, 128);
}
}

}

2.package org.tjitcast.demo;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;

public class UploadBean {
public void doUpload(HttpServletRequest request) throws IOException {
PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(
"d:\\zah.txt")));
ServletInputStream in = request.getInputStream();
int i = in.read();
while (i != -1) {
pw.print((char) i);
i = in.read();
}
pw.close();
}
}

3.<%@ page contentType="text/html;charset=gb2312"%>
<html>
<head>
<title>文件上载</title>
<style>
input{border:1px solid green;}
</style>

</head>
<body>
<form action="up.jsp" enctype="MULTIPART/FORM-DATA" method=post>
作者:
<input type="text" name="author" />
<br />
公司:
<input type="text" name="company" />
<br />
选择要上载的文件
<input type="file" name="filename" />
<br />
<input type="submit" value="上载" />
</form>
</body>
</html>

4.<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<html>
<head>

</head>

<body>
<jsp:useBean id="TheBean" scope="page" class="com.hbsi.csdn.upload.UploadBean">
<%
TheBean.doUpload(request);
%>

</jsp:useBean>
</body>
</html>