fileupload.java

本程序是作者用JBuilder 开发的一个娱乐系统模块.

package com.singnet.util;

import java.io.*;

import javax.servlet.*;
import javax.servlet.http.*;

public class FileUpload {
    private int fieldNumber = 20; //上传文件或者文本输入框的数目
    private String[] sourceFileName = new String[fieldNumber]; //源文件名
    private String[] sourceFileExt = new String[fieldNumber]; //文件后缀名
    private String allow = ".gif.jpg.jpeg.zip.rar"; //可上传的文件后缀名
    private String savePath = "."; //目标文件目录
    private String[] objectFileName = new String[fieldNumber]; //目标文件名
    private String[] fileField = new String[fieldNumber]; //保存文件表单里对应的文本框的name值
    private ServletInputStream inStream = null; //输入流
    private String[] fileMessage = new String[fieldNumber]; //文件上传错误消息
    private long size = 100 * 1024; //限制文件大小
    private int fileCount = 0; //已传输文件数目，包括不符合类型和大小的，但这类文件不会上传
    private byte[] b = new byte[4096]; //字节流存放数组
    private boolean ok = true; //文件上传状态
    private String[] textField = new String[fieldNumber]; //文本字段
    private String[] textFieldValue = new String[fieldNumber]; //文本字段值
    private String[] textMessage = new String[fieldNumber]; //表单处理错误消息
    private int textCount = 0; //处理的文本框数目
    public String contextPath = ""; //当前context对应的绝对路径
    //Constractor
    public FileUpload() {
    }

    public void init(javax.servlet.jsp.PageContext pageContext) {
        if (pageContext == null) {
            return;
        }
        String path = pageContext.getServletContext().getRealPath("/");
        path = path.replace('\\', '/');
        int length = path.length();
        if (path.charAt(length - 1) == '/') {
            path = path.substring(0, length - 1);
        }
        this.contextPath = path;
    }

    //设置输入框的数目
    public void setFieldNumber(int n) {
        this.fieldNumber = n;
    }

    //设置允许上传的文件后辍
    public void setAllow(String allow) {
        this.allow = allow;
    }

    //设置上传的文件保存路径
    public void setSavePath(String path) {
        this.savePath = path;
    }

    //设置文件最大字节数
    public void setSize(long s) {
        this.size = s;
    }

    //获得允许上传的文件后辍
    public String getAllow() {
        return this.allow;
    }

    //获得上传的文件保存路径
    public String getSavePath() {
        return this.savePath;
    }

    //获得上传文件个数
    public int getFileCount() {
        return this.fileCount;
    }

    //获得File域数组
    public String[] getFileField() {
        return this.fileField;
    }

    //获得上传后文件名数组
    public String[] getObjectFileName() {
        return this.objectFileName;
    }

    //获得源文件名数组
    public String[] getSourceFileName() {
        return this.sourceFileName;
    }

    //获得上传文件信息
    public String[] getFileMessage() {
        return this.fileMessage;
    }

    //获得文本域个数
    public int getTextCount() {
        return this.textCount;
    }

    //获得文本域name数组
    public String[] getTextField() {
        return this.textField;
    }

    //获得文本域value数组
    public String[] getTextFieldValue() {
        return this.textFieldValue;
    }

    //获得文本域信息
    public String[] getTextMessage() {
        return this.textMessage;
    }


    //处理ServletInputStream
    public void doStream(HttpServletRequest request) throws IOException {
        this.inStream = request.getInputStream();

        int readLength = 0;
        int offset = 0;
        String str = "";
        int a = 0;
        int b = 0;
        String formName = "";
        boolean fileExtOk = false;
        String formTextName = "";

        while ((readLength = this.inStream.readLine(this.b, 0, this.b.length)) !=
                             -1) { //readLength为实际读入b的字节数，-1表示到达流末端
            str = new String(this.b, 0, readLength);

            //文件
            if ((offset = str.indexOf("filename=\"")) != -1) {
                //获得上传文件Form中对应的输入框的变量名
                a = str.indexOf("name=\"");
                formName = str.substring(a + 6);
                b = formName.indexOf("\"");
                formName = formName.substring(0, b);
                this.fileField[this.fileCount] = formName;

                //获得得源文件名
                str = str.substring(offset + 10);
                b = str.indexOf("\"");
                str = str.substring(0, b);
                if (str.equals("") || str == "") {
                    this.fileField[this.fileCount] = "";
                    continue;
                }
                this.sourceFileName[this.fileCount] = str;

                //获得文件扩展名
                a = this.sourceFileName[this.fileCount].lastIndexOf(".");
                this.sourceFileExt[this.fileCount] = this.sourceFileName[this.
                        fileCount].substring(a + 1);

                //检查文件扩展名
                fileExtOk = this.checkFileExt(this.fileCount);
                if (fileExtOk) {
                    this.doUpload(this.fileCount);
                    this.fileCount++;
                } else {
                    this.objectFileName[fileCount] = "none";
                    this.fileCount++;
                    continue;
                }
            }
            //文本域
            else if ((offset = str.indexOf("name=\"")) != -1) {
                //获得表单中的name值
                formTextName = str.substring(offset + 6);
                a = formTextName.indexOf("\"");
                formTextName = formTextName.substring(0, a);
                this.textField[textCount] = formTextName;

                this.getInputValue(textCount);

                this.textCount++;
            } else {
                continue;
            }
        }
    }

    //检查文件扩展名是否符合要求
    public boolean checkFileExt(int fileCount) {
        if ((this.allow.indexOf(sourceFileExt[fileCount])) != -1) {
            return true;
        } else {
            this.fileMessage[fileCount] = "上传文件错误：不允许上传该类型的文件！";
            return false;
        }
    }

    //上传文件
    public boolean doUpload(int count) {
        //获得当前时间，作为上传后的文件名
        String objFileName = Long.toString(new java.util.Date().getTime()) +
                             String.valueOf(count);
        try {
            this.objectFileName[count] = objFileName + "_bak." +
                                         this.sourceFileExt[count];

            File objFile = new File(this.contextPath + "/" + this.savePath,
                                    this.objectFileName[count]);
            //如果文件已存在
            if (objFile.exists()) {
                //再次调用自己
                //再次调用可发以重新生成文件名
                this.doUpload(count);
            } else {
                objFile.createNewFile();
            }

            FileOutputStream fos = new FileOutputStream(objFile);
            BufferedOutputStream bos = new BufferedOutputStream(fos);

            int readLength = 0;
            int offset = 0;
            String str = "";
            long readSize = 0L; //已经读取的大小，用以判断文件大小是否超过规定长度

            //将指针移至Content-Type:这一行
            while ((readLength = this.inStream.readLine(this.b, 0,
                    this.b.length)) != -1) {
                str = new String(this.b, 0, readLength);
                if (str.indexOf("Content-Type:") != -1) {
                    break;
                }
            }

            //读空白行
            this.inStream.readLine(this.b, 0, this.b.length);

            while ((readLength = this.inStream.readLine(this.b, 0, b.length)) !=
                                 -1) {
                //检查文件是否已经读取完成
                str = new String(this.b, 0, readLength);
                if (this.b[0] == 45 && this.b[1] == 45 && this.b[2] == 45 &&
                    this.b[3] == 45 && this.b[4] == 45) {
                    break;
                }

                //写入文件
                bos.write(this.b, 0, readLength);

                readSize += readLength;

                if (readSize > this.size) {
                    this.fileMessage[count] = "上传文件错误：文件大小超过限制！";
                    this.ok = false;
                    break;
                }
            }

            if (this.ok) { //上传成功
                bos.flush();
                bos.close();

                //读入已上传文件中的内容，去掉未尾的"\n"
                int fileLength = (int) (objFile.length());
                byte[] bb = new byte[fileLength - 2];
                FileInputStream fis = new FileInputStream(objFile);
                BufferedInputStream bis = new BufferedInputStream(fis);
                bis.read(bb, 0, (fileLength - 2));
                fis.close();
                bis.close();

                //输出去掉"\n"后的文件
                this.objectFileName[count] = objFileName + "." +
                                             this.sourceFileExt[count];
                File ok_file = new File(this.contextPath + "/" + this.savePath,
                                        this.objectFileName[count]);
                ok_file.createNewFile();
                BufferedOutputStream bos_ok = new BufferedOutputStream(
                        new FileOutputStream(ok_file));
                bos_ok.write(bb);
                bos_ok.close();
                objFile.delete();

                this.fileMessage[count] = "OK";
                return true;
            } else { //失败
                bos.flush();
                bos.close();
                File delFile = new File(this.contextPath + "/" + this.savePath,
                                        this.objectFileName[count]);
                delFile.delete();
                this.objectFileName[count] = "none";
                return false;
            }

        } catch (Exception e) {
            this.objectFileName[count] = "none";
            this.fileMessage[count] = e.toString();
            return false;
        }

    }

    //获得Input内容
    public boolean getInputValue(int count) {
        String str = "";
        int readLength = 0;
        try {
            this.inStream.readLine(this.b, 0, this.b.length);

            StringBuffer formTextValue = new StringBuffer();

            //获得值
            while ((readLength = this.inStream.readLine(this.b, 0,
                    this.b.length)) != -1) {
                str = new String(this.b, 0, readLength);
                if (this.b[0] == 45 && this.b[1] == 45 && this.b[2] == 45 &&
                    this.b[3] == 45 && this.b[4] == 45) {
                    break;
                }
                formTextValue.append(str);
            }

            str = formTextValue.toString();
            this.textFieldValue[count] = str.substring(0, str.length() - 2);
            this.textMessage[count] = "OK";
            return true;
        } catch (Exception e) {
            this.textFieldValue[count] = "td_none";
            this.textMessage[count] = "获得文本字段错误" + e.toString();
            return false;
        }
    }
}