java中文件操作的工具类

代码：

package com.lky.pojo;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

import org.junit.After;
import org.junit.Ignore;
import org.junit.Test;

/**
* @Title: fileUtil.java 
* @Package com.lky.pojo 
* @Description: 文件操作的工具类
* @author lky 
* @date 2015年10月20日 下午4:21:35 
* @version V1.0
 */
public class fileUtil {
    
    /**
    * @Title: stringToFile 
    * @Description: 将字符串存入文件(适用于任何类型的数据:图片，音频，视频，文本)
    * @param  str  待存储的字符串
    * @param  fname 文件名
    * @param  flag    是否以追加的方式写入文件
     */
    public void stringToFile(String str, String fname, boolean flag) {
        FileOutputStream fos = null;
        File file = new File(fname);
        try {
            if (!file.exists()) {
                String parentName = file.getParent();// 获取父文件夹名
                new File(parentName).mkdirs();// 创建父文件夹
                file.createNewFile();
            }
            fos = new FileOutputStream(file, flag);
            fos.write(str.getBytes());
            fos.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    
    /**
    * @Title: StringToFileBuffered 
    * @Description: 将字符串存入文件(仅在存入的数据为纯文本时，推荐使用，其它类型不使用)
    * @param  str  待存储的字符串
    * @param  fname 文件名
    * @param  flag    是否以追加的方式写入文件
     */
    public void StringToFileBuffered(String str, String fame, boolean flag) {
        BufferedWriter bw = null;
        FileWriter fw = null;
        File file = new File(fame);

        try {
            if (!file.exists()) {
                new File(file.getParent()).mkdirs();
                file.createNewFile();
            }

            fw = new FileWriter(file, flag);
            bw = new BufferedWriter(fw);

            bw.write(str);
            bw.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {

                if (bw != null) {
                    bw.close();
                }
                if (fw != null) {
                    fw.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
    }
    
    /**
    * @Title: fileToStringBuffered 
    * @Description: 从文件中读入字符串(仅当该文件为文本文件，推荐使用)
    * @param 文件名
     */
    public String fileToStringBuffered(String fname) {
        BufferedReader br = null;
        FileReader fr = null;
        StringBuffer sBuffer = new StringBuffer();
        File file = new File(fname);

        try {
            if (!file.exists()) {
                return sBuffer.append(new String("文件不存在")).toString();
            }

            fr = new FileReader(file);
            br = new BufferedReader(fr);

            String line = null;
            while ((line = br.readLine()) != null) {
                sBuffer.append(line+"
");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (br != null) {
                    br.close();
                }
                if (fr != null) {
                    fr.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return sBuffer.toString();
    }
    
    /**
    * @Title: fileToStringBurstMode 
    * @Description: 从文件中读入数据(快字节流方式)
    * @param 文件名
     */
    public String fileToStringBurstMode(String fname) {
        File file = new File(fname);
        FileInputStream fis = null;
        StringBuffer sBuffer = new StringBuffer();
        try {
            if (!file.exists()) {
                System.out.println("文件不存在。。。。");
                return sBuffer.toString();
            }
            fis = new FileInputStream(file);
            int length = fis.available();
            if (length <= 0)
                return sBuffer.toString();
            ;
            byte[] buffer = new byte[length];
            int offset = 0;
            int toRead = length - offset;
            while (toRead > 0) {
                int len = fis.read(buffer, offset, toRead);
                offset += len;
                toRead -= len;
            }
            sBuffer.append(new String(buffer, "utf-8"));
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return sBuffer.toString();
    }

    /**
    * @Title: filetoStringSlowMode 
    * @Description: 从文件中读入数据(慢字节流方式)
    * @param 文件名
     */
    public String filetoStringSlowMode(String fname) {
        FileInputStream fis = null;
        ByteArrayOutputStream baos = null;
        StringBuffer sBuffer = new StringBuffer();
        File file = new File(fname);

        try {
            if (!file.exists()) {
                return sBuffer.append("该文件不存在").toString();
            }

            baos = new ByteArrayOutputStream();
            fis = new FileInputStream(file);
            int len = 0;
            while ((len = fis.read()) != -1) {
                baos.write(len);
            }

            sBuffer.append(baos.toString());
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (fis != null) {
                    fis.close();
                }
                if (baos != null) {
                    baos.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return sBuffer.toString();
    }

    @Test
    @Ignore
    public void test1() {
        stringToFile("l love you " + "
", "c:\li\one.txt", true);
    }

    @After
    public void testAfter() {
        System.out.println("---------------------------");
    }

    @Test
    @Ignore
    public void test2() {
        System.out.println(fileToStringBurstMode("c:\one.txt"));
    }

    @Test
    @Ignore
    public void test3() {
        System.out.println(filetoStringSlowMode("c:\one.txt"));
    }
    
    @Test
    public void test4(){
        System.out.println(fileToStringBuffered("c:\zhang\one.txt"));
    }
    
    @Test
    @Ignore
    public void test5(){
        StringToFileBuffered("l love you " + "
", "c:\zhang\one.txt", true);
    }
}