Java io 操作

package tlistpackage;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

/**
 * @author Administrator
 *
 */
public class listdemo {
  public static void main(String[] args) throws IOException
  {
//    System.out.println(Runtime.getRuntime().getClass());
//    System.out.println(Math.round(23.55));
//    System.out.println(Math.ceil(26.333));
//    System.out.println((int)(Math.random()*10+1));
//    Date d=new Date();
//    System.out.println(d.toString());
//    //格式化时间
//    System.out.println(DateFormat.getDateInstance().format(d));
//     char[] buffer=new char[1024];
//                          int len=0;
//    while((len=rf.read(buffer))!=-1)
//    {
//      System.out.print(new String(buffer,0,len));
//    }
//    WriteFile("txtdemo.txt","dirk.wang");
//    String textString= ReadFile("txtdemo.txt");
//    System.out.print(textString);
//    InputWriteFile("txtdemo.txt","dirk.wang,show time");
//    String str= InputReadFile("txtdemo.txt");
//    System.out.print(str);
    CopyFile("txtdemo.txt","new.txt");
  }


  /**
   * @param path 路径
   * @return
   */
  @SuppressWarnings("finally")
  public static String ReadFile(String path) 
  {
    FileReader fs=null;
    String str="";
    try {
       fs=new FileReader(path);
      char[] buffer =new char[1024];
      int len=0;

      while((len=fs.read(buffer))!=-1)
      {
        str+=new String(buffer,0,len);
      }
    } catch (FileNotFoundException e) {
            e.printStackTrace();
    }catch (IOException e) {
      e.printStackTrace();
    }
    finally {
      if(fs!=null)
      {
        try {
          fs.close();
        } catch (IOException e2) {
          e2.printStackTrace();
        }
      }
      return str;
    }
  }

  /**
   * @param path  路径
   * @param text  写入的内容
   */
  public static void WriteFile(String path,String text)
  {
    FileWriter fw =null;
    try {
      //true 表示追加写入文件
      fw=new FileWriter(path,true);
      fw.write(text);
      //fw.write(text);
      fw.flush();
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    }catch (IOException e) {
      // TODO: handle exception
      e.printStackTrace();
    }finally {
      if(fw!=null)
      {
        try {
          fw.close();
        } catch (IOException e2) {
          // TODO: handle exception
          e2.printStackTrace();
        }
      }
    }
  }


  /**
   * 通过二进制流读取文件
   * @param path  路径
   * @return
   */
  public static String InputReadFile(String path)
  {
    File file=new File(path);
    StringBuilder str=new StringBuilder();
    if(file.isFile())
    {
      FileInputStream fs=null;
      try {
        fs=new FileInputStream(file);
        byte[] buffer=new byte[1024];
        int len=0;
        while((len=fs.read(buffer))!=-1)
        {
          str.append(new String(buffer,0,len));
        }
      } catch (IOException e) {
        // TODO: handle exception
        e.printStackTrace();
      }finally {
        if(fs!=null)
        {
          try {
            fs.close();
          } catch (IOException e2) {
            // TODO: handle exception
            e2.printStackTrace();
          }
        }
      }
    }

    return str.toString();
  }

  /**
   * @param path  路径
   * @param text  内容
   */
  public static void InputWriteFile(String path,String text)
  {
    File file=new File(path);
    FileOutputStream fos=null;
    if(file.isFile())
    {
      try {
        fos=new FileOutputStream(file,true);
        fos.write(text.getBytes());
        fos.flush();
      } catch (IOException e) {
        // TODO: handle exception
        e.printStackTrace();
      }finally {
        if(fos!=null)
        {
          try {
            fos.close();
          } catch (IOException e) {
            // TODO: handle exception
            e.printStackTrace();
          }
        }
      }

    }
  }

  public static void CopyFile(String oldPath,String newPath)
  {
    FileInputStream fis=null;
    FileOutputStream fos=null;
    try {
      fis=new FileInputStream(oldPath);
      fos=new FileOutputStream(newPath);
      int len=0;
      byte[] buffer =new byte[1024];
      while((len=fis.read(buffer))!=-1)
      {
        fos.write(buffer,0,len);
        fos.flush();
      }
    } catch (IOException e) {
      // TODO: handle exception
      e.printStackTrace();
    }finally {
      try {
        fis.close();
        fos.close();
      } catch (IOException e2) {
        // TODO: handle exception
        e2.printStackTrace();
      }
    }
  }
}