几个典型的节点流:
FileOutputStream在你没有那个文件的时候会自动帮你建立一个
FileInputStream的例子代码:
import java.io.*; public class TestFileInputStream { public static void main(String[] args) { int b = 0; FileInputStream in = null; try { in = new FileInputStream("D:/打码家族/java/mine/testIoStream/TestFileInputStream.java"); } catch (FileNotFoundException e) { System.out.println("找不到指定文件"); System.exit(-1); } try { long num = 0; while((b=in.read())!=-1) {//read一次就是读一个字节 System.out.print((char)b);//它一个字节一个字节的读,然后每个字节再把它强制转换 num++; } in.close(); System.out.println(); System.out.println("一共读取了"+num+"个字节"); } catch(IOException e) { System.out.println("文件读取错误!"); System.exit(-1); } } }
FileOutputStream例子代码:
import java.io.*; public class TestFileOutputStream { public static void main(String[] args) { int b = 0; FileInputStream in = null;//一根往程序输入东西的管 FileOutputStream out = null;//一根往文件传入东西的管 try { in = new FileInputStream("D:/打码家族/java/mine/casting/Casting.java");//这跟管插入一个文件中,准备往外读数据 out = new FileOutputStream("D:/打码家族/java/mine/testIoStream/Try.java");//FileOutputStream这个类在你没有这个文件的时候会帮你建立一个 } catch(FileNotFoundException e) { System.out.println("找不到指定文件"); } try { while((b = in.read())!=-1) { out.write(b); } in.close(); out.close(); } catch(IOException e) { System.out.println("文件复制错误!"); } System.out.println("文件已复制!"); } }
FileReader例子代码:
import java.io.*; public class TestFile2 { public static void main(String[] args) { int b = 0; FileReader fr = null; try { fr = new FileReader("D:/打码家族/java/mine/testIoStream/TestFile2.java"); while( (b=fr.read())!=-1 ) { System.out.print((char)b); } fr.close(); } catch(FileNotFoundException e) { System.out.println("没有找到指定文件"); }catch(IOException e) { System.out.println("文件读取错误!"); } } }
FileWriter例子代码:
import java.io.*; public class TestFile2 { public static void main(String[] args) { int b = 0; FileWriter fw = null; try { fw = new FileWriter("D:/打码家族/java/mine/testIoStream/Unicode.dat"); for(int i = 0; i < 50000 ; i++) { fw.write(i); } fw.close(); } catch(FileNotFoundException e) { System.out.println("没有找到指定文件"); }catch(IOException e) { System.out.println("文件读取错误!"); System.exit(-1); } } }
写入单个字符i