java中outputStream与inputStream的相互转换

/*做一个功能验证，要用到inputStream与outputStream的转换，本以为很简单的东东
搞了蛮久，从"程序员 闫帆"处取得一段代码*/
package com.boco.test;



import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.io.OutputStream;



public class ConvertUtil {

    //inputStream转outputStream

    public ByteArrayOutputStream parse(InputStream in) throws Exception

    {

        ByteArrayOutputStream swapStream = new ByteArrayOutputStream();

        int ch;

        while ((ch = in.read()) != -1) {   

            swapStream.write(ch);   

        }

        return swapStream;

    }

    //outputStream转inputStream

    public ByteArrayInputStream parse(OutputStream out) throws Exception

    {

        ByteArrayOutputStream   baos=new   ByteArrayOutputStream();

        baos=(ByteArrayOutputStream) out;

        ByteArrayInputStream swapStream = new ByteArrayInputStream(baos.toByteArray());

        return swapStream;

    }

    //inputStream转String

    public String parse_String(InputStream in) throws Exception

    {

        ByteArrayOutputStream swapStream = new ByteArrayOutputStream();

        int ch;

        while ((ch = in.read()) != -1) {   

            swapStream.write(ch);   

        }

        return swapStream.toString();

    }

    //OutputStream 转String

    public String parse_String(OutputStream out)throws Exception

    {

        ByteArrayOutputStream   baos=new   ByteArrayOutputStream();

        baos=(ByteArrayOutputStream) out;

        ByteArrayInputStream swapStream = new ByteArrayInputStream(baos.toByteArray());

        return swapStream.toString();

    }

    //String转inputStream

    public ByteArrayInputStream parse_inputStream(String in)throws Exception

    {

        ByteArrayInputStream input=new ByteArrayInputStream(in.getBytes());

        return input;

    }

    //String 转outputStream

    public ByteArrayOutputStream parse_outputStream(String in)throws Exception

    {

        return parse(parse_inputStream(in));

    }

}