WriteClientServlet.java

/**
 * Copyright (c) 2005-2012 https://github.com/zhangkaitao
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.sishuok.chapter4.web.servlet.nonblocking;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 *
 *  写数据客户端，{@link ReadServlet} 负责读
 *
 * <p>User: Zhang Kaitao
 * <p>Date: 13-7-20 下午3:52
 * <p>Version: 1.0
 */
@WebServlet(name = "writeClientServlet", urlPatterns = "/writeClient")
public class WriteClientServlet extends HttpServlet {

    @Override
    protected void doGet(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException {
        resp.setHeader("Connection", "Keep-Alive");
        resp.addHeader("Cache-Control", "private");
        resp.addHeader("Pragma", "no-cache");
        resp.setContentType("text/html;charset=utf-8");
        resp.getWriter().write("正在写数据...");
        resp.getWriter().flush();
        resp.flushBuffer();

        StringBuilder url = new StringBuilder("http://");
        url.append(req.getLocalAddr());
        url.append(":");
        url.append(req.getLocalPort());
        url.append(req.getContextPath());
        url.append("/read");

        HttpURLConnection conn = (HttpURLConnection) new URL(url.toString()).openConnection();
        //设置是否向httpUrlConnection输出，默认false
        conn.setDoOutput(true);
        //设置块大小（字节），当写满后自动flush（这个用于不知道实际大小，以块的方式去写）
        //sun.net.www.http.ChunkedOutputStream
        conn.setChunkedStreamingMode(2);

        //sun.net.www.protocol.http.HttpURLConnection#StreamingOutputStream
        //设置固定长度（如文件上传，我们知道实际要传输的大小）
        //conn.setFixedLengthStreamingMode(1024);

        //默认是如下输出流，即写完最后自己flush，即只有最后关闭时才刷出数据
        //sun.net.www.http.PosterOutputStream

        //post方式提交
        conn.setRequestMethod("POST");
        OutputStream os = new BufferedOutputStream(conn.getOutputStream());

        for(int i = 1; i <= 10 * 100; i++) {
            os.write(("hello" + i).getBytes("ISO-8859-1"));
            try {
                if(i % 20 == 0) { //每写20次 flush下，等待1秒
                    os.flush();
                    Thread.sleep(1000L);
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }

        os.close();//如果注释掉这行，可能导致服务器端没有读取完数据抛出java.io.EOFException，此刻将回调ReadListener#onError
        conn.disconnect(); //释放连接

        resp.getWriter().write("客户端写数据完成...");
        resp.getWriter().flush();
        resp.flushBuffer();
    }
}