I/O流

package type;import java.io.*;import java.util.Scanner;public class IAndO {public static void main(String[] args) throws IOException {//从文件中读取InputStream is = new FileInputStream(new File(".project"));//字节流System.out.println(is);System.out.println(is.read());//字节流转换为字符流Reader re = new InputStreamReader(is);//字符流char[] ch = new char[1024];re.read(ch, 0,1024 );for (char c : ch){System.out.print(c);}Scanner sc = new Scanner(new File(".project"));//字符流while(sc.hasNext()){System.out.println(sc.nextLine());}System.out.println("11111");FileReader reader = new FileReader(new File(".project"));char[] c = new char[1024];int ready = reader.read(c);//返回读取的字节reader.close();//若关闭，使用BufferedReader读取时会抛出异常System.out.println(new String(c,0,ready));Reader readery = new FileReader(new File(".classPath"));BufferedReader breader = new BufferedReader(readery);char[] cc= new char[1024];System.out.println("11111");int len = breader.read(cc);breader.close();System.out.println(len);System.out.println(new String(cc));//写入文件PrintWriter pw = new PrintWriter(new File("copy.txt"));pw.print(cc);//写入for(char cha : cc)pw.append(cha);//追加,写入charpw.append('s');//使用刷新或关闭，否则可能文件中没有内容，//由于读取的内容在一个缓冲区内，只有当缓冲区满，或关闭，或刷新时，才会输入到文件pw.flush();pw.close();Writer wr = new FileWriter(new File("copy2.txt"));wr.write(c, 0, ready);wr.close();//字符流与字节流之间的转换OutputStream out = new FileOutputStream(new File(".txt"));//将字符存储为指定编码集的字节OutputStreamWriter writer = new OutputStreamWriter(out,"UTF-8");writer.write(cc,0,len);writer.close();}}