java读取文件及文件流 博客分类： java JavaJSPServlet

package cn.xx.io.util;

import java.io.*;
import java.util.*;
import javax.servlet.jsp.PageContext;
import com.kingter.common.httpclient.*;

/**
 * <p>Title: 文件管理</p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2010</p>
 * <p>Company:  </p>
 * @author  
 * @version 1.0
 */

public class FileManagerService {

    public FileManager() {
    }

    /**
     * 创建文件
     * @param fileName String 文件名，包含文件路径
     * @param buf byte[] 文件内容
     * @throws java.lang.Exception 创建文件失败，抛出异常
     */
    public void createFile(String fileName, byte[] buf) throws Exception {
        String sDir = fileName.substring(0, fileName.lastIndexOf("/"));
        //System.out.println("dir == " + sDir);
        //创建目录
        File dir = new File(sDir);
        if (!dir.exists()) {
            dir.mkdirs();
        }

        //创建文件
        File file = new File(fileName);
        //if(!file.exists()) {
        //System.out.println("文件长度 == " + buf.length);
        if (buf != null && buf.length > 0) {
            FileOutputStream fOut = new FileOutputStream(fileName);
            fOut.write(buf, 0, buf.length);
            fOut.close();
        }
        //}
    }

    /**
     * 删除文件
     * @param fileName String 文件名，包含文件路径
     * @return int 成功 >0；失败 -1
     */
    public int deleteFile(String fileName) {
        int results = 0;
        File file = new File(fileName);
        if (file.exists()) {
            if (file.delete()) {
                results = results + 1;
            }
        }
        return results;
    }

    /**
     * 删除文件夹
     * @param dirName String 文件夹名称，包含文件夹路径
     * @return int 成功 >0；失败 -1
     */
    public int deleteDir(String dirName) {
        int results = 0;
        File dir = new File(dirName);
        File[] files = dir.listFiles();
        for (int i = 0; i < files.length; i++) { //删除目录下的所有文件
            if (files[i].exists()) {
                files[i].delete();
            }
        }

        if (dir.exists()) { //删除目录
            if (dir.delete()) {
                results = results + 1;
            }
        }
        return results;
    }

    /**
     * 批量删除物理文件
     * @param arrfile String[]  //被删除文件数组
     * @throws Exception
     * @return int 成功返回被删除文件个数，失败返回0
     */
    public int deletePhysicsFile(String[] arrfile) throws Exception {
        int results = 0;
        for (int i = 0; i < arrfile.length; i++) {
            File fl = new File(arrfile[i]);
            if (fl.exists()) {
                if (fl.delete()) {
                    results = results + 1;
                }
            }
        }
        return results;
    }

    /**
     * 写文件方法。
     * @param filename String       文件名
     * @param arrcontent String[]   内容数组
     * @param isappend boolean      是否追尾
     * @throws Exception
     */
    public void WriteFile(String filename, String strcontent,
                          boolean isappend) throws Exception {
        File f1 = new File(filename);
        if (!f1.exists()) {
            f1.createNewFile();
        }
        FileWriter fr = new FileWriter(filename, isappend);
        BufferedWriter w1 = new BufferedWriter(fr);
        w1.write(strcontent);
        w1.newLine();
        w1.close();
        fr.close();
    }

    /**
     * 根据相对路径获得绝对路径
     * @param pagecontext PageContext
     * @param dirPath String 相对路径
     * @return String 绝对路径
     */
    public String getPath(PageContext pagecontext, String dirPath) {
        String tempPath = pagecontext.getServletContext().getRealPath("");
        Properties properties = System.getProperties();
        String separator = properties.getProperty("file.separator");
        String path = "";
        if (separator.equals("\\")) {
            path = tempPath.substring(0, tempPath.lastIndexOf("\\")) + dirPath;
            path = path.replaceAll("\\\\", "/");
        }
        else {
            path = tempPath.substring(0, tempPath.lastIndexOf("/")) + dirPath;
        }
        return path;
    }

    /**
     * 创建目录
     * @param dirPath String 目录
     */
    public void mkdir(String dirPath) {
        java.io.File dir = new java.io.File(dirPath);
        if (!dir.exists()) {
            dir.mkdirs();
        }
    }

    public static String getValue(String parament) {
        String textContent = "";
        File file = new File(parament);

        try {
            BufferedReader input = new BufferedReader(new FileReader(file));
            StringBuffer buffer = new StringBuffer();
            String text;
            int lines = 0;

            while ( (text = input.readLine()) != null) {
                buffer.append(text + "\n");
                lines += 1;
            }
            input.close();
            textContent = buffer.toString();
        }
        catch (Exception ex) {
        }
        return textContent;
    }
    /**
       * 读取源文件内容
       * @param filename String 文件路径
       * @throws IOException
       * @return byte[] 文件内容
       */
    public  byte[] readFileToByte(String filename) throws IOException {

        File file =new File(filename);
        if(filename==null || filename.equals(""))
        {
          throw new NullPointerException("无效的文件路径");
        }
        long len = file.length();
        byte[] bytes = new byte[(int)len];
        BufferedInputStream bufferedInputStream=new BufferedInputStream(new FileInputStream(file));
        int r = bufferedInputStream.read( bytes );
        if (r != len)
          throw new IOException("读取文件不正确");
        bufferedInputStream.close();
        return bytes;

    }


    public static void main(String[] args) {
        
    }

}