J2SE基础-IO-字节流(位流)-多目标源输出流自定义扩展
J2SE基础-IO-字节流(位流)-多目标源输出流自定义扩展
前一章节（J2SE基础-IO-字节流(位流)）对字节流(位流)进行了说明，对于输入字节流InputStream/输出字节流OutputStream，我们可以根据业务的实际情况进行自定义的实现。
以下制作了一个多目标源输出流的扩展，作为前一章节的补充。
package com.core.common.file.stream;import java.io.IOException;import java.io.OutputStream;import java.util.List;import com.core.common.log.Log;/** * 文件名称: MultiOutputStream.java * 类名: MultiOutputStream * 日期: 2012-12-22 * * 功能描述：多目的源输出流，该对象同时将一个输入流写入多个输出流 */public class MultiOutputStream extends OutputStream {/** 多目的源输出流的保存对象*/private List<OutputStream> outputStreamList = null;/** * 构造方法 * 功能描述：初始化多目的源输出流 * * @param outputStreamList * @throws IOException */public MultiOutputStream(final List<OutputStream> outputStreamList) throws IOException {if(outputStreamList == null || outputStreamList.isEmpty()) {final String msg = "多源输出流对象为null，不能进行初始化操作，请检查！";Log.logDebug(msg);throw new IOException(msg);}int outputStreamListSize = outputStreamList.size();for (int i = 0; i < outputStreamListSize; i++) {OutputStream outputStream = outputStreamList.get(i);if(outputStream == null) {outputStreamList.remove(i);Log.logDebug("多源输出流对象中发现第[{}]个是null，该输出源已从输出列表中删除，请检查！", i);}}this.outputStreamList = outputStreamList;}/** * 重写write方法 * 重载方法(non-Javadoc) * @see java.io.OutputStream#write(int) */@Overridepublic void write(final int b) throws IOException {if(this.outputStreamList != null) {for (OutputStream outputStream : this.outputStreamList) {outputStream.write(b);}}}/** * 重写write方法 * 重载方法(non-Javadoc) * @see java.io.OutputStream#write(byte[], int, int) */@Overridepublic void write(final byte[] data, final int offset, final int length) throws IOException {if(this.outputStreamList != null) {for (OutputStream outputStream : this.outputStreamList) {outputStream.write(data, offset, length);}}}/** * 重写flush方法 * 重载方法(non-Javadoc) * @see java.io.OutputStream#flush() */@Overridepublic void flush() throws IOException {if(this.outputStreamList != null) {for (OutputStream outputStream : this.outputStreamList) {outputStream.flush();}}}/** * 重写close方法 * 重载方法(non-Javadoc) * @see java.io.OutputStream#close() */@Overridepublic void close() throws IOException {if(this.outputStreamList != null) {for (OutputStream outputStream : this.outputStreamList) {outputStream.close();}}}}/** * 方法名称: copyToMultiOutput * 功能描述: 将输入流拷贝至多输出源 * * @version 1.0 * * @param inputStream InputStream 输入流 * @param outputStream OutputStream 多目的源输出流 * @throws IOException * * @update [日期YYYY-MM-DD] [更改人姓名] [变更描述] */public void copyToMultiOutput(final InputStream inputStream,final List<OutputStream> outputStreamList) throws IOException {MultiOutputStream multiOut = new MultiOutputStream(outputStreamList);copy(inputStream, multiOut);}/** * 方法名称: copy * 功能描述: 该方法实现输出源输出 * * @version 1.0 * * @param inputStream InputStream 输入流 * @param outputStream OutputStream 多目的源输出流 * @throws IOException * * @update [日期YYYY-MM-DD] [更改人姓名] [变更描述] */private static void copy(final InputStream inputStream, final OutputStream outputStream) throws IOException {if(inputStream == null) {throw new IOException("没有输入流，拷贝操作停止！");}if(outputStream == null) {throw new IOException("没有输出源，拷贝操作停止！");}// 缓冲流BufferedInputStream bin = new BufferedInputStream(inputStream);BufferedOutputStream bout = new BufferedOutputStream(outputStream);while (true) {int datum = bin.read();if(datum == -1) {break;}bout.write(datum);}// 刷新缓冲区bout.flush();bout.close();return;}