java io读取文件操作代码实例

package com.io;import org.junit.Test;import java.io.*;public class FileTest {	//1、字节流字节一个一个读取	@Test	  public void test() throws IOException{		InputStream fis = new FileInputStream(new File("E:/project_test/src/com/io/readme.txt"));		int len;		//按字节一个一个读取		while ((len = fis.read())!=-1){			System.out.print((char)len+"t");    };    fis.close();  }//输出结果h  e  l  l  o  w  o  r  l  d    //2、字节流字节数组读取  @Test  public void test1() throws IOException{    InputStream fis = new FileInputStream(new File("E:/project_test/src/com/io/readme.txt"));    byte[] bytes = new byte[2];    int len ;    //按字节数组读取 bytes存储的是读取的数据    while ((len = fis.read(bytes))!=-1){      System.out.print((new String(bytes))+"t");    };    fis.close();  }//输出结果 he  ll  ow  or  ld    //3、缓冲字节流字节一个一个读取  @Test  public void test2() throws IOException{    BufferedInputStream bis = new BufferedInputStream(new FileInputStream(new File("E:/project_test/src/com/io/readme.txt")));    int len ;    while ((len = bis.read())!=-1){      System.out.print((char)len+"t");    };    bis.close();  }//输出结果h  e  l  l  o  w  o  r  l  d   //4、缓冲字节流字节数组读取  @Test  public void test3() throws IOException{    BufferedInputStream bis = new BufferedInputStream(new FileInputStream(new File("E:/project_test/src/com/io/readme.txt")));    byte[] bytes = new byte[3];    int len ;    //按字节数组读取 bytes存储的是读取的数据    while ((len = bis.read(bytes))!=-1){      System.out.print(new String(bytes)+"t");    };    bis.close();  }//输出结果hel  low  orl  drl    //5、字符流一个一个读取  @Test  public void test4() throws IOException{    InputStreamReader isr = new InputStreamReader(new FileInputStream(new File("E:/project_test/src/com/io/readme.txt")));    int len ;    //按字节数组读取 bytes存储的是读取的数据    while ((len = isr.read())!=-1){      System.out.print((char)len+"t");    };    isr.close();  }  //6、字符流字符数组读取  @Test  public void test5() throws IOException{    InputStreamReader isr = new InputStreamReader(new FileInputStream(new File("E:/project_test/src/com/io/readme.txt")));    char[] chars = new char[3];    int len ;    //按字节数组读取 bytes存储的是读取的数据    while ((len = isr.read(chars))!=-1){      System.out.print(new String(chars)+"t");    };    isr.close();  }  //7、缓冲字符流字符一个一个读取  @Test  public void test6() throws IOException{    BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(new File("E:/project_test/src/com/io/readme.txt"))));    int len ;    //按字节数组读取 bytes存储的是读取的数据    while ((len = br.read())!=-1){      System.out.print((char)len+"t");    };    br.close();  }  //8、缓冲字符流字符数组读取  @Test  public void test7() throws IOException{    BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(new File("E:/project_test/src/com/io/readme.txt"))));    char[] chars = new char[3];    int len ;    //按字节数组读取 bytes存储的是读取的数据    while ((len = br.read(chars))!=-1){      System.out.print(new String(chars)+"t");    };    br.close();  }  //9、缓冲字符流按行读取  @Test  public void test8() throws IOException{    BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(new File("E:/project_test/src/com/io/readme.txt"))));    //按字节数组读取 bytes存储的是读取的数据    String str;    while ( (str = br.readLine())!=null){      System.out.print(str+"t");    };    br.close();  }}