1019课堂内容

package text;

import java.io.*;

//文本文件操作类
public class file {

private String fileName;

public String getFileName()
{
return fileName;
}
//构造
private File file;

public  file(String fileName)
{
this.fileName = fileName;

file = new File(fileName);
}

//创建文件
public void create() throws IOException
{

if(!file.exists())//如果文件不存在
{
file.createNewFile();
System.out.println("文件创建成功！");
}
else
{
System.out.println("文件已存在！");
}
}
//删除文件
public void delete()
{
File file = new File(fileName);

if(file.exists())//如果文件存在
{
file.delete();
System.out.println("删除成功！");
}
else
{
System.out.println("文件不存在！");
}
}
//修改内容
public void edit(String strEdit) throws IOException//修改内容以参数形式传输进去
{
if(file.exists())
{
FileWriter fw = new FileWriter(file);

BufferedWriter bfw = new BufferedWriter(fw);

bfw.write(strEdit);

bfw.close();
}
else
{
System.out.println("文件不存在！");
}
}
//追加内容
public void addLine(String strLine) throws IOException//新加行，并传输内容
{
if(file.exists())
{
String str = readFile();

FileWriter fw = new FileWriter(file);

BufferedWriter bfw = new BufferedWriter(fw);

//bfw.newLine();

bfw.write(str+"\n"+strLine);

bfw.close();
}
else
{
System.out.println("文件不存在！");
}
}
public String readFile() throws IOException
{
String rtn = "";

if(file.exists())
{
FileReader fr = new FileReader(file);

BufferedReader br = new BufferedReader(fr);

String s = "";

while((s = br.readLine()) != null)
{
rtn += s + "\n";
}
br.close();
}
else
{
System.out.println("文件不存在！");
}
return rtn;
}
}