Java代码

packagestar20110526;

importjava.io.BufferedInputStream;

importjava.io.BufferedOutputStream;

importjava.io.BufferedReader;

importjava.io.File;

importjava.io.FileInputStream;

importjava.io.FileNotFoundException;

importjava.io.FileOutputStream;

importjava.io.FileReader;

importjava.io.IOException;

importjava.io.InputStreamReader;

importjava.io.PrintStream;

importjava.io.PrintWriter;

publicclassRedirecting {

publicstaticvoidmain(String[] args)throwsIOException {

redirect();

//      readFile();

//      write("B05\\star20110526\\Redirecting.txt", read());

}

privatestaticvoidredirect()throwsIOException{

//将输出定位到PrintStrem，将 System.out重新定义ouputStream

PrintStream printStream = System.out;

//定义输入流

BufferedInputStream bufferedInputStream = newBufferedInputStream(

newFileInputStream("B05\\star20110526\\Redirecting.java"));

//定义输出流

PrintStream printStream2 = newPrintStream(

newBufferedOutputStream(newFileOutputStream("B05\\star20110526\\Redirect.out")));

//本来System.in是接受控制台参数的，现在将System.in重新定义到bufferedInputStream

System.setIn(bufferedInputStream);

System.setErr(printStream2);

System.setOut(printStream2);

//InputStreamReader 为适配器，转换inputStream到Reader，你懂的

BufferedReader bufferedReader = newBufferedReader(newInputStreamReader(System.in));

String string;

while((string = bufferedReader.readLine()) !=null){

System.out.println(string);

}

printStream.close();

printStream2.close();

bufferedReader.close();

System.setOut(printStream);

}

/**

* 读取文件，然后直接在控制台打印出来

* @throws IOException

*/

privatestaticvoidreadFile()throwsIOException{

File file = newFile("B05\\star20110526\\Redirecting.java");

FileReader fileReader = newFileReader(file);

BufferedReader bufferedReader = newBufferedReader(fileReader);

inti =1;

String string;

while((string = bufferedReader.readLine()) !=null){

System.out.println(i++ +":"+string);

}

bufferedReader.close();

}

/**

* 读取文件，返回文件内容，提供文件写入操作

* @return

* @throws IOException

*/

privatestaticString read()throwsIOException{

File file = newFile("B05\\star20110526\\Redirecting.java");

BufferedReader bufferedReader = newBufferedReader(

newFileReader(file));

StringBuilder stringBuilder = newStringBuilder();

String string;

while((string  = bufferedReader.readLine()) !=null){

stringBuilder.append(string+"\n");

}

returnstringBuilder.toString();

}

/**

* 新建一个文件，然后往文件里面写文件咯

* @param file

* @param text

* @throws FileNotFoundException

*/

privatestaticvoidwrite(String file,String text)throwsFileNotFoundException{

File file2 = newFile(file);

PrintWriter printWriter = newPrintWriter(file2);

printWriter.write(text);

//必须关闭流，要不然出不来结果的，(╰_╯)#(╰_╯)#(╰_╯)#

printWriter.close();

}

}package star20110526;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.FileReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintStream;

import java.io.PrintWriter;

public class Redirecting {

public static void main(String[] args) throws IOException {

redirect();

//readFile();

//write("B05\\star20110526\\Redirecting.txt", read());

}

private static void redirect() throws IOException{

//将输出定位到PrintStrem，将 System.out重新定义ouputStream

PrintStream printStream = System.out;

//定义输入流

BufferedInputStream bufferedInputStream = new BufferedInputStream(

new FileInputStream("B05\\star20110526\\Redirecting.java"));

//定义输出流

PrintStream printStream2 = new PrintStream(

new BufferedOutputStream(new FileOutputStream("B05\\star20110526\\Redirect.out")));

//本来System.in是接受控制台参数的，现在将System.in重新定义到bufferedInputStream

System.setIn(bufferedInputStream);

System.setErr(printStream2);

System.setOut(printStream2);

//InputStreamReader 为适配器，转换inputStream到Reader，你懂的

BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

String string;

while((string = bufferedReader.readLine()) != null){

System.out.println(string);

}

printStream.close();

printStream2.close();

bufferedReader.close();

System.setOut(printStream);

}

/**

* 读取文件，然后直接在控制台打印出来

* @throws IOException

*/

private static void readFile() throws IOException{

File file = new File("B05\\star20110526\\Redirecting.java");

FileReader fileReader = new FileReader(file);

BufferedReader bufferedReader = new BufferedReader(fileReader);

int i = 1;

String string;

while((string = bufferedReader.readLine()) != null){

System.out.println(i++ +":"+string);

}

bufferedReader.close();

}

/**

* 读取文件，返回文件内容，提供文件写入操作

* @return

* @throws IOException

*/

private static String read() throws IOException{

File file = new File("B05\\star20110526\\Redirecting.java");

BufferedReader bufferedReader = new BufferedReader(

new FileReader(file));

StringBuilder stringBuilder = new StringBuilder();

String string;

while((string = bufferedReader.readLine()) != null){

stringBuilder.append(string+"\n");

}

return stringBuilder.toString();

}

/**

* 新建一个文件，然后往文件里面写文件咯

* @param file

* @param text

* @throws FileNotFoundException

*/

private static void write(String file,String text) throws FileNotFoundException{

File file2 = new File(file);

PrintWriter printWriter = new PrintWriter(file2);

printWriter.write(text);

//必须关闭流，要不然出不来结果的，(╰_╯)#(╰_╯)#(╰_╯)#

printWriter.close();

}

}