java 学习5 .io

简单的读写文件。简单的固定了编码utf-8 和覆盖模式 overwrite file.

package com.linson;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public abstract class IOFile 
{
    public static void Write2File(String filePath,String content,boolean isappend)
    {
        try 
        {
            File f = new File(filePath);
            FileOutputStream fop = new FileOutputStream(f);
            OutputStreamWriter writer = new OutputStreamWriter(fop, "UTF-8");
            writer.append(content);
            writer.close();
            fop.close();
        } 
        catch (IOException e) 
        {  
            //e.printStackTrace();  
        }
    }
    
    public static String readFromStringFile(String filePath)
    {
        String retString=null;
        try
        {
            File f = new File(filePath);
            FileInputStream finoutStream=new FileInputStream(f);
            InputStreamReader reader=new InputStreamReader(finoutStream, "UTF-8");
            
            StringBuffer sb = new StringBuffer();
            while (reader.ready()) 
            {
                sb.append((char) reader.read());
            }
            retString=sb.toString();
            
            reader.close();
            finoutStream.close();
        }
        catch(IOException e)
        {
            retString=null;
        }
        
        return retString;
    }
}

public static void Study_io()
    {
        //write ; 1.no file. 2.rewaite or append. 3. code.
        String tempstrString="好的阿.你哈噢阿"+System.lineSeparator()+"abc";
        IOFile.Write2File("test2.txt", tempstrString, false);
        
        IOFile.Write2File("ee.txt", "", false);
        
        
        //read 1.file is null. 2.empty file . 3 code .4 line
        String retstr="";
        retstr= IOFile.readFromStringFile("test2.txt");
        System.out.println(retstr);
    }