文章目录 Buffered流拷贝二进制文件 创建文件写入文本 读取文本文件 存读Properties文件
Buffered流拷贝二进制文件
package com. hspedu. chapter19. outputStream ; import java. io. * ; public class BufferedCopy02 { public static void main ( String [ ] args) { String srcFilePath = "c:\\bh.jpg" ; String destFilePath = "c:\\hsp.jpg" ; BufferedInputStream bis = null ; BufferedOutputStream bos = null ; try { bis = new BufferedInputStream ( new FileInputStream ( srcFilePath) ) ; bos = new BufferedOutputStream ( new FileOutputStream ( destFilePath) ) ; byte [ ] buff = new byte [ 1024 ] ; int readLen = 0 ; while ( ( readLen = bis. read ( buff) ) != - 1 ) { bos. write ( buff, 0 , readLen) ; } System . out. println ( "Copied successfully.." ) ; } catch ( IOException e) { throw new RuntimeException ( e) ; } finally { try { bis. close ( ) ; bos. close ( ) ; } catch ( IOException e) { throw new RuntimeException ( e) ; } } }
}
创建文件写入文本
import java. io. BufferedWriter ;
import java. io. File ;
import java. io. FileWriter ;
import java. io. IOException ; public class Homework01 { public static void main ( String [ ] args) throws IOException { String filePath = "c:\\mydir" ; File file = new File ( filePath) ; if ( ! file. exists ( ) ) { if ( file. mkdirs ( ) ) System . out. println ( filePath + " has been created successfully.." ) ; else System . out. println ( filePath + " was fail to be created.." ) ; } else { System . out. println ( filePath + " has already existed.." ) ; } String destfile = filePath + "\\hello.txt" ; File file1 = new File ( destfile) ; if ( ! file1. exists ( ) ) { if ( file1. createNewFile ( ) ) { BufferedWriter bufferedWriter = new BufferedWriter ( new FileWriter ( file1) ) ; bufferedWriter. write ( "hello, world~~ 韩顺平教育" ) ; bufferedWriter. close ( ) ; System . out. println ( destfile + " has been created successfully.." ) ; } else { System . out. println ( destfile + " has already existed.." ) ; } } else { System . out. println ( destfile + " has already existed.." ) ; } }
}
读取文本文件
public class Homework02 { public static void main ( String [ ] args) throws IOException { String filePath = "c:\\hello.txt" ; String line = "" ; int lineNum = 0 ; BufferedReader bufferedReader = new BufferedReader ( new FileReader ( filePath) ) ; while ( ( line = bufferedReader. readLine ( ) ) != null ) { System . out. println ( ++ lineNum + " " + line) ; } if ( bufferedReader != null ) bufferedReader. close ( ) ; }
}
public class Homework02 { public static void main ( String [ ] args) throws IOException { String filePath = "c:\\hello.txt" ; InputStreamReader isr = new InputStreamReader ( new FileInputStream ( filePath) , "gbk" ) ; String line = "" ; int lineNum = 0 ; BufferedReader bufferedReader = new BufferedReader ( isr) ; while ( ( line = bufferedReader. readLine ( ) ) != null ) { System . out. println ( ++ lineNum + " " + line) ; } if ( bufferedReader != null ) bufferedReader. close ( ) ; }
}
存读Properties文件
public class Homework03 { public static void main ( String [ ] args) throws IOException { String filePath = "src\\dog.properties" ; Properties properties = new Properties ( ) ; properties. load ( new FileReader ( filePath) ) ; String name = properties. get ( "name" ) + "" ; int age = Integer . parseInt ( properties. get ( "age" ) + "" ) ; String color = properties. get ( "color" ) + "" ; Dog dog = new Dog ( name, age, color) ; System . out. println ( "===dog对象信息====" ) ; System . out. println ( dog) ; String serFilePath = "c:\\dog.dat" ; ObjectOutputStream oos = new ObjectOutputStream ( new FileOutputStream ( serFilePath) ) ; oos. writeObject ( dog) ; oos. close ( ) ; System . out. println ( "dog对象,序列化完成..." ) ; } @Test public void m1 ( ) throws IOException , ClassNotFoundException { String serFilePath = "e:\\dog.dat" ; ObjectInputStream ois = new ObjectInputStream ( new FileInputStream ( serFilePath) ) ; Dog dog = ( Dog ) ois. readObject ( ) ; System . out. println ( "===反序列化后 dog====" ) ; System . out. println ( dog) ; ois. close ( ) ; }
} class Dog implements Serializable { private String name; private int age; private String color; public Dog ( String name, int age, String color) { this . name = name; this . age = age; this . color = color; } @Override public String toString ( ) { return "Dog{" + "name='" + name + '\'' + ", age=" + age + ", color='" + color + '\'' + '}' ; }
}