基于Netty框架的demo项目

package pers.ran.server.test; import io.netty.buffer.ByteBuf; import io.netty.buffer.PooledByteBufAllocator; import io.netty.buffer.Unpooled; public class BufTest { public static void main(String[] argo) throws Exception{ testByteBuf(); } public static void testByteBuf() throws Exception { // 创建byteBuf对象，该对象内部包含一个字节数组byte[10] // 通过readerindex和writerIndex和capacity，将buffer分成三个区域 // 已经读取的区域：[0,readerindex) // 可读取的区域：[readerindex,writerIndex) // 可写的区域: [writerIndex,capacity) ByteBuf byteBuf = Unpooled.buffer(500 * 1024, 1024 * 1024); System.out.println("写入前 byteBuf -> " + byteBuf); //long maxSize = 117483647; long maxSize = 100; int cnt = 0; for (long i = 0; i < maxSize; i++) { byteBuf.writeLong(i); System.out.println("第"+i+"次写入后 byteBuf ->" + byteBuf + ", 可写字节：" + byteBuf.writableBytes() + ", 可读字节：" + byteBuf.readableBytes()); cnt++; if (cnt == 50) { for (int j = 0; j < cnt; j++) { byteBuf.readByte(); } System.out.println("读取后 byteBuf ->" + byteBuf + ", 可读字节：" + byteBuf.readableBytes()); // 读取后 byteBuf ->PooledUnsafeHeapByteBuf(ridx: 87028702, widx: 696229616, cap: 696254464) byteBuf.discardReadBytes(); //Thread.sleep(10000); cnt = 0; } } System.out.println("写入后 byteBuf ->" + byteBuf); /*StringBuilder stringBuilder = new StringBuilder(); stringBuilder.append("执行getByte方法:"); for (int i = 0; i < 5; i++) { stringBuilder.append(byteBuf.getByte(i)).append(" "); } System.out.println(stringBuilder.toString()); System.out.println("调用getByte方法后 byteBuf ->" + byteBuf); stringBuilder.setLength(0); stringBuilder.append("执行readByte方法:"); for (int i = 0; i < 5; i++) { stringBuilder.append(byteBuf.readByte()).append(" "); } System.out.println(stringBuilder.toString()); System.out.println("调用readByte方法后 byteBuf ->" + byteBuf);*/ } /** * 四种典型的内存分配方式 * 性能测试，每种运行一千万次，每次分配1000个字节，并写入同样的字符串 */ public static void testBufAllocator() { Long start = System.currentTimeMillis(); System.out.println("执行开始时间：" + start); ByteBuf buf = null; String str = "程就人生，程就你我"; //池化直接内存 for(int i=0;i<10000000;i++){ buf = PooledByteBufAllocator.DEFAULT.directBuffer(1000); buf.writeBytes(str.getBytes()); buf.release(); } Long end1 = System.currentTimeMillis(); System.out.println("PooledByteBufAllocator.DEFAULT.directBuffer 池化直接内存 ,执行结束时间：" + (end1-start)); //池化堆内存 for(int i=0;i<10000000;i++){ buf = PooledByteBufAllocator.DEFAULT.heapBuffer(1000); buf.writeBytes(str.getBytes()); buf.release(); } Long end2 = System.currentTimeMillis(); System.out.println("PooledByteBufAllocator.DEFAULT.heapBuffer 池化堆内存,执行结束时间：" + (end2-end1)); //非池化直接内存 for(int i=0;i<10000000;i++){ buf = Unpooled.directBuffer(1000); buf.writeBytes(str.getBytes()); buf.release(); } Long end3 = System.currentTimeMillis(); System.out.println("Unpooled.directBuffer 非池化直接内存,执行结束时间：" + (end3-end2)); //非池化堆内存 for(int i=0;i<10000000;i++){ buf = Unpooled.buffer(1000); buf.release(); } Long end4 = System.currentTimeMillis(); System.out.println("Unpooled.buffer 非池化堆内存,执行结束时间：" + (end4-end3)); } }