Java Writer

Writer是一個用於寫字元流的抽象類。其子類必須實現write(char[], int, int), flush(), 和 close()方法。

類定義

public abstract class Writer
extends Object
implements Appendable, Closeable, Flushable

屬性

Modifier and Type    Field    Description
protected Object    lock    The object used to synchronize operations on this stream.

建構函式

protected    Writer()
Creates a new character-stream writer whose critical sections will synchronize on the writer itself.

常用方法

Writer        append(char c)                                    往writer追加指定字元
Writer        append(CharSequence csq)                        追加指定字元序列
Writer        append(CharSequence csq, int start, int end)    追加指定字元序列的子序列
abstract     void    close()                                    先沖刷後關閉流
abstract     void    flush()                                    沖刷流
void        write(char[] cbuf)                                寫字元陣列
abstract     void    write(char[] cbuf, int off, int len)    寫字元陣列的部分
void        write(int c)                                    寫單個字元
void        write(String str)                                寫字串

void        write(String str, int off, int len)                寫部分字串

例子

package com.dylan.io;

import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;

/**
 * @author xusucheng
 * @create 2018-01-07
 **/
public class WriterExample {
    public static void main(String[] args) throws IOException {
        Writer w = new FileWriter("D:\\output.txt");
        String content = "I love my country.";
        w.write(content);
        w.close();
        System.out.println("Done.");
    }
}

Java Reader

Reader 是一個用於讀取字元流的抽象類。其子類必須實現的方法只有：read(char[], int, int) 和 close()。

實現類包括： BufferedReader, CharArrayReader, FilterReader, InputStreamReader, PipedReader, StringReader

類定義

public abstract class Reader
extends Object
implements Readable, Closeable

屬性

protected Object

lock The object used to synchronize operations on this stream.

建構函式

protected	Reader() Creates a new character-stream reader whose critical sections will synchronize on the reader itself.
protected	Reader(Object lock) Creates a new character-stream reader whose critical sections will synchronize on the given object.

常用方法

abstract void	close() Closes the stream and releases any system resources associated with it.
void	mark(int readAheadLimit) Marks the present position in the stream.
boolean	markSupported() Tells whether this stream supports the mark() operation.
int	read() Reads a single character.
int	read(char[] cbuf) Reads characters into an array.
abstract int	read(char[] cbuf, int off, int len) Reads characters into a portion of an array.
int	read(CharBuffer target) Attempts to read characters into the specified character buffer.
boolean	ready() Tells whether this stream is ready to be read.
void	reset() Resets the stream.
long	skip(long n) Skips characters.

例子

package com.dylan.io;

import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;

/**
 * @author xusucheng
 * @create 2018-01-07
 **/
public class ReaderExample {
    public static void main(String[] args) throws IOException{
        Reader r = new FileReader("D:\\output.txt");
        int data = 0;
        while ((data=r.read())!=-1){
            System.out.print((char)data);
        }

        r.close();
    }
}

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