java String writer reader

Java里经常会有将输入输出流的来源或目录设定为一个字符串，实现方法有两种
第一种，使用StringReader或StringWriter，但是只有writer，不能转换为InputStream或OutputStream
示例

package net.nyist.io;

import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;

public class StringNodeTest {

	public static void main(String[] args) {

		String src = "从明天起，做一个幸福的人，\n喂马，劈材，周游世界，\n从明天起，关心粮食和蔬菜，\n我有一所房子，面朝大海，春暖花开，\n从明天起，和每一个人通信，告诉他们我的幸福\n";

		char[] buffer = new char[32];
		int hasRead = 0;
		
		try(
				StringReader sr = new StringReader(src);
				
				){
			//采用循环读取的方式，读取字符串
			while((hasRead  = sr.read(buffer))> 0 ){
				//
				System.out.println(new String(buffer,0,hasRead));
			}
		}catch(IOException ioe){
			
			ioe.printStackTrace();
		}
		
		try(
				//
				StringWriter sw = new StringWriter();
				){
			//调用方法执行输出
			sw.write("有一个美丽的新世界\n");
                        writer.flush(); 
			sw.write("有一个美丽的新世界\n");
                        writer.flush(); 
			sw.write("有一个美丽的新世界\n");
                        writer.flush(); 
			sw.write("有一个美丽的新世界\n");
                        writer.flush(); 
			sw.write("有一个美丽的新世界\n");
			writer.flush();  
			System.out.println(sw.toString());
			
		}catch(IOException ioe){
			
			ioe.printStackTrace();
			
		}
		
	}

}

writer.flush(); 方法在写入以后一定要调用，将字符从缓冲区写入目标区，
否则输出的字符串会有不完整的情况。
BufferedReader.readLine()方法，读入时，行尾的换行符是不会读入的，需要换行时
需要重新追加换行符\n。


第二种方法 使用ByteArrayInputStream

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * 
 * @author Andy.Chen
 * @mail [email protected]
 *
 */
public class InputStreamUtils {
	
	final static int BUFFER_SIZE = 4096;
	
	/**
	 * 将InputStream转换成String
	 * @param in InputStream
	 * @return String
	 * @throws Exception
	 * 
	 */
	public static String InputStreamTOString(InputStream in) throws Exception{
		
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		byte[] data = new byte[BUFFER_SIZE];
		int count = -1;
		while((count = in.read(data,0,BUFFER_SIZE)) != -1)
			outStream.write(data, 0, count);
		
		data = null;
		return new String(outStream.toByteArray(),"ISO-8859-1");
	}
	
	/**
	 * 将InputStream转换成某种字符编码的String
	 * @param in
	 * @param encoding
	 * @return
	 * @throws Exception
	 */
         public static String InputStreamTOString(InputStream in,String encoding) throws Exception{
		
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		byte[] data = new byte[BUFFER_SIZE];
		int count = -1;
		while((count = in.read(data,0,BUFFER_SIZE)) != -1)
			outStream.write(data, 0, count);
		
		data = null;
		return new String(outStream.toByteArray(),"ISO-8859-1");
	}
    
    /**
     * 将String转换成InputStream
     * @param in
     * @return
     * @throws Exception
     */
    public static InputStream StringTOInputStream(String in) throws Exception{
    	
    	ByteArrayInputStream is = new ByteArrayInputStream(in.getBytes("ISO-8859-1"));
    	return is;
    }
    
    /**
     * 将InputStream转换成byte数组
     * @param in InputStream
     * @return byte[]
     * @throws IOException
     */
    public static byte[] InputStreamTOByte(InputStream in) throws IOException{
    	
    	ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		byte[] data = new byte[BUFFER_SIZE];
		int count = -1;
		while((count = in.read(data,0,BUFFER_SIZE)) != -1)
			outStream.write(data, 0, count);
		
		data = null;
		return outStream.toByteArray();
    }
    
    /**
     * 将byte数组转换成InputStream
     * @param in
     * @return
     * @throws Exception
     */
    public static InputStream byteTOInputStream(byte[] in) throws Exception{
    	
    	ByteArrayInputStream is = new ByteArrayInputStream(in);
    	return is;
    }
    
    /**
     * 将byte数组转换成String
     * @param in
     * @return
     * @throws Exception
     */
    public static String byteTOString(byte[] in) throws Exception{
    	
    	InputStream is = byteTOInputStream(in);
    	return InputStreamTOString(is);
    }

}