Java IO测试样例-字节流-字符流
//***
* java中的IO详解见 http://www.senma.org/blogs/356.html
* 也可以参考：http://www.cnblogs.com/rollenholt/archive/2011/09/11/2173787.html
*/
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.io.PrintStream;
import java.io.SequenceInputStream;
import java.net.URL;
import java.net.URLConnection;
/****
*
* @author masen
* http://weibo.com/masen
* http://www.senma.org/
*
*/
public class ReadFileTest {
/***
* 字符流读取文本
* @throws IOException
*/
public static void readerReadFile(String filename)
{
//BufferedReader reader=new BufferedReader(new FileReader(name));
//因为Filereader继承InputStreamReader 故两种写法都是ok的
BufferedReader reader=null;
try {
reader = new BufferedReader(new InputStreamReader(new FileInputStream(filename)));
String s1="";
while((s1=reader.readLine())!=null)
{
System.out.println(s1);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally
{
try {
if(reader!=null)reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/***
* 字节流读取文本
* 字节流读取web信息，同理
* @throws IOException
*/
public static void streamReadFile(String filename)
{
FileInputStream stream=null;
try {
stream=new FileInputStream(filename);
byte[] temp=new byte[1024];
int len=0;
while((len=stream.read(temp))!=-1)
{//注意因为temp缓存是固定字节长，不能全部output
System.out.print(new String(temp,0,len));
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally
{
try {
if(stream!=null)stream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/***
* 网络读取数据，使用字符流
* 这里可以明显看到InputstreamReader是 stream到reader的桥梁
* @param url
*/
public static void readerReadWeb(String url)
{
BufferedReader reader=null;
try {
URLConnection con=new URL(url).openConnection();
reader=new BufferedReader(new InputStreamReader(con.getInputStream()));
String s1="";
while((s1=reader.readLine())!=null)
{
System.out.println(s1);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally
{
try {
if(reader!=null)reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/***
* 递归罗列目录
*
* @param dir 当前文件目录
* @param name 当前文件名
* @param deep 当前递归深度
* @param dept 允许的最大深度
*/
public static void listDir(String dir,String name,int deep,int dept)
{
File f=new File(dir+File.separator+name);
for(int i=0;i<deep;i++)
System.out.print(" ");
if(f.isDirectory())
{
String[] dirs=f.list();
System.out.print("--"+name);
if(dirs==null||dirs.length==0)
{
return;
}
System.out.print("\r\n");
for(String s:dirs)
{
if((deep+1)<dept)
listDir(dir+File.separator,s,deep+1,dept);
}
}
else
{
System.out.print("--"+name);
System.out.print("\r\n");
}
}
/***
* 字节流写入文件
* @param file
* @param content
*/
public static void streamWriteFile(String name,String content)
{
File f=new File(name);
FileOutputStream stream=null;
try {
if(!f.exists())
{//文件不存在
f.createNewFile();
stream=new FileOutputStream(f);
byte[] temp=content.getBytes();
stream.write(temp);
}
else
{//文件存在则追加
stream=new FileOutputStream(f,true);
byte[] temp=content.getBytes();
for(int i=0;i<temp.length;i++)
stream.write(temp[i]);
}
} catch (IOException e) {
e.printStackTrace();
}
finally
{
try {
if(stream!=null)
stream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
/***
* 字符流写入文件
* @param file
* @param content
*/
public static void writerWriteFile(String name,String content)
{
File f=new File(name);
FileWriter stream=null;
try {
if(!f.exists())
{//文件不存在
f.createNewFile();
stream=new FileWriter(f);
stream.write(content);
}
else
{//文件存在则追加
stream=new FileWriter(f,true);
stream.write(content);
}
} catch (IOException e) {
e.printStackTrace();
}
finally
{
try {
if(stream!=null)
stream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
/***
* 管道字节流测试
* 字符流测试类似
*
*/
public class PipeWriter implements Runnable
{
private PipedOutputStream out = null;
private String content;
public PipeWriter()
{
out=new PipedOutputStream();
}
public PipedOutputStream getOut() {
return out;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
public void run() {
while(content!=null&&!content.equals(""))
{
try {
out.write(content.getBytes());
content="";
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
public class PipeReader implements Runnable
{
private PipedInputStream in = null;
public PipeReader()
{
in=new PipedInputStream();
}
public void run() {
byte[] buf = new byte[1024];
try {
int len = in.read(buf);
System.out.println(new String(buf,0,len));
//in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public PipedInputStream getIn() {
return in;
}
}
/***
* printstream测试
* 可见printstream不直接针对具体的输出流形态
* 对比同类型的FileOutputStream 它更抽象化，相当于写操作的封装接口：把写的内容交给输出流，具体实现完全不管。
*
* System.out可以重定向为对应的stream流
* 同理System.in也可以如此。不再举例。
*/
public static void printStreamTest()
{
PrintStream print=null;
try {
print = new PrintStream(new FileOutputStream(new File("d:"
+ File.separator + "hello.txt"),true));
print.println("我喜欢你");
print.printf("姓名：%s. 年龄：%d.","杨幂",15);
print.close();
print=new PrintStream(System.out);
print.println("我喜欢你");
print.printf("姓名：%s. 年龄：%d.","杨幂",15);
print.close();
//重定向系统输出流，例如log4j
print = new PrintStream(new FileOutputStream(new File("d:"
+ File.separator + "hello.txt"),true));
System.setOut(print);
System.out.println("打死你");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/****
* sequenceinputstream测试，将两个input流按照先后顺序合并。
* @param name1
* @param name2
*/
public static void sequenceInput(String name1,String name2)
{
try {
InputStream a=new FileInputStream(name1);
InputStream b=new FileInputStream(name2);
SequenceInputStream s=new SequenceInputStream(a,b);
BufferedReader r=new BufferedReader(new InputStreamReader(s));
String t="";
while((t=r.readLine())!=null)
{
System.out.println(t);
}
a.close();
b.close();
s.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* @param args
*/
public static void main(String[] args) {
//streamReadFile("c:/t1.txt");
//readerReadFile("c:/t1.txt");
//listDir("d:","",0,4);
//streamWriteFile("d:/1.txt","杨幂");
//streamWriteFile("d:/1.txt","刘恺威");
//writerWriteFile("d:/2.txt","杨幂");
//writerWriteFile("d:/2.txt","刘恺威");
/***
ReadFileTest t=new ReadFileTest();
PipeWriter x=t.new PipeWriter();
PipeReader y=t.new PipeReader();
Thread w=new Thread(x);
Thread r=new Thread(y);
try {
x.getOut().connect(y.getIn());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
x.setContent("111");
w.start();
r.start();
x.setContent("111");
**/
///printStreamTest();
sequenceInput("d:/1.txt","d:/2.txt");
}
}
