package test;import java.io.File;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.io.Reader;import java.io.Writer;import java.util.ArrayList;import java.util.List;public class ArraysDemo{public static void main(String args[]) throws IOException{write1();read1();write2();read2();}public static void write1() throws IOException{File f = new File("d:"+File.separator+"text.txt") ;// 实例化File类的对象Writer out=new FileWriter(f);out.write("hello");out.close();}public static void write2() throws IOException{File f = new File("d:"+File.separator+"text.txt") ;// 实例化File类的对象Writer out=new FileWriter(f,true);out.write("\r\nword");//\r\n换行out.close();}public static void read1() throws IOException{File f = new File("d:"+File.separator+"text.txt") ;// 实例化File类的对象Reader input=new FileReader(f);char[] c=new char[1024];int len=input.read(c);input.close();System.out.println("read1():\n"+new String(c,0,len));}public static void read2() throws IOException{File f = new File("d:"+File.separator+"text.txt") ;// 实例化File类的对象Reader input=new FileReader(f);int temp=0;List<Character> list=new ArrayList<Character>();while((temp=input.read())!=-1){list.add((char)temp);}char[] b=new char[list.size()];for(int i=0,j=list.size();i<j;i++){b[i]=list.get(i);}input.close();System.out.println("read2():\n"+new String(b));}};/**read1():helloread2():hellohello**/
，每一件事都要用多方面的角度来看它
