commons-io实现流的拷贝
一、使用工具的原因
对于流的copy的代码是比较复杂的
例如：实现图片的请求
@WebServlet("/img")public class MyServlet HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1. 读取文件FileInputStream fis = new FileInputStream("d://fengjie.jpg");//2. 获取response字节输出流ServletOutputStream os = response.getOutputStream();//3. 完成流的copybyte[] buff = new byte[1024];int len = 0;while ((len = fis.read(buff))!= -1){os.write(buff,0,len);}fis.close();}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}}
二、使用commons-io工具进行代码优化
pom.xml添加依赖<dependency><groupId>commons-io</groupId><artifactId>commons-io</artifactId><version>2.6</version></dependency>
调用工具类方法
//fis:输入流//os:输出流IOUtils.copy(fis,os);
优化之后的代码
@WebServlet("/img")public class MyServlet HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1. 读取文件FileInputStream fis = new FileInputStream("d://fengjie.jpg");//2. 获取response字节输出流ServletOutputStream os = response.getOutputStream();//3. 完成流的copyIOUtils.copy(fis,os);fis.close();}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}}
