文件的读写

//创建文件及文件夹的方法
public void create(File file)
{
if(!file.exists())
{
try 
{
file.createNewFile();//创建文件
file.mkdir();//创建文件夹
}
catch (IOException e) 
{
e.printStackTrace();
}
}
}

//删除文件的方法
public void delete(File file)
{
if(file.exists())
{
file.delete();
}
}

//遍历文件夹下的所有文件
public void queryAllFile()
{
File file = new File("E:\\");
File[] fileList = file.listFiles();//file文件夹里的所有文件
String[] fileNames = file.list();//file文件下所有文件的名字，带有后缀
for(int i = 0; i<fileList.length;i++)
{
if(fileList[i].isFile())
{
System.out.println(fileList[i].getName()+"----"+fileList[i].getPath());
String[] fileName = "pwd.jsp".split("\\.");
System.out.println(fileNames[i] + "====" + fileName[0]+"+++"+fileName[1]);
}
}
}

//以字符读取和写入数据
public void readByByte()
{
File source = new File("revSource.txt");
File result = new File("revResult.txt");
try {
FileReader fr = new FileReader(source);
FileWriter fw = new FileWriter(result,true);//true表示不覆盖原来的
BufferedReader br = new BufferedReader(fr);
BufferedWriter bw = new BufferedWriter(fw);
String line = br.readLine();
while(null != line)
{
bw.write(line);
bw.newLine();
line = br.readLine();
}
bw.close();
fw.close();
br.close();
fr.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch (IOException e) {
e.printStackTrace();
};

}

//以字节读取和写入数据
public void readByChar()
{
File source = new File("revSource.txt");
File result = new File("revResult.txt");
try {
FileInputStream fis = new FileInputStream(source);
FileOutputStream fos = new FileOutputStream(result,true);//true表示不覆盖原来的
byte[] buffer = new byte[1024];
int count = 0;
while((count = fis.read(buffer)) != -1)
{
fos.write(buffer,0,count);//一次读取1024个字节，不到1024的读取count个字节
fos.flush();
}
fos.close();
fis.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch (IOException e) {
e.printStackTrace();
};
}