Netty+SpringBoot整合（一）
目录
- 一 Netty+SpringBoot环境搭建
-
- 1.1 服务端
- 1.2 客户端
- 1.3 测试
- 二 Netty实现简单的文件传输
-
- 2.1 实体类
- 2.2 服务端
- 2.3 客户端
- 2.4 测试
Netty官网：Netty: Home
前面我们介绍了Netty的基本用法以及基本知识，但是在我们的实际开发中要用到SpringBoot，下面我们来看看SpringBoot的整合与简单的文件传输吧
一 Netty+SpringBoot环境搭建
依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
</dependency>
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.65.Final</version>
</dependency>
<!-- 修复 Apache Log4j2 远程代码执行漏洞 -->
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.17.0</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.17.0</version>
</dependency>
yaml配置
server:
port:8080
netty:
host: 127.0.0.1
port: 7397
下面我们分别搭建服务端与客户端
1.1 服务端
package com.shu;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import java.net.InetSocketAddress;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 10:27
* @version: 1.0
*/
@Component("nettyServer")
public class NettyServer {
private Logger logger = LoggerFactory.getLogger(NettyServer.class);
private final EventLoopGroup parentGroup = new NioEventLoopGroup();
private final EventLoopGroup childGroup = new NioEventLoopGroup();
private Channel channel;
/**
* 绑定端口
* @param address
* @return
*/
public ChannelFuture bind(InetSocketAddress address) {
ChannelFuture channelFuture = null;
try {
ServerBootstrap b = new ServerBootstrap();
b.group(parentGroup, childGroup)
.channel(NioServerSocketChannel.class) //非阻塞模式
.option(ChannelOption.SO_BACKLOG, 128)
.childHandler(new MyChannelInitializer());
channelFuture = b.bind(address).syncUninterruptibly();
channel = channelFuture.channel();
} catch (Exception e) {
logger.error(e.getMessage());
} finally {
if (null != channelFuture && channelFuture.isSuccess()) {
logger.info("netty server start done.");
} else {
logger.error("netty server start error.");
}
}
return channelFuture;
}
/**
* 销毁
*/
public void destroy() {
if (null == channel) return;
channel.close();
parentGroup.shutdownGracefully();
childGroup.shutdownGracefully();
}
/**
* 获取通道
* @return
*/
public Channel getChannel() {
return channel;
}
}
package com.shu;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import java.nio.charset.Charset;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 10:31
* @version: 1.0
*/
public class MyChannelInitializer extends ChannelInitializer<SocketChannel> {
/**
* 初始化channel
* @param channel
* @throws Exception
*/
@Override
protected void initChannel(SocketChannel channel) throws Exception {
// 日志打印
channel.pipeline().addLast(new LoggingHandler(LogLevel.INFO));
// 基于换行符号
channel.pipeline().addLast(new LineBasedFrameDecoder(1024));
// 解码转String，注意调整自己的编码格式GBK、UTF-8
channel.pipeline().addLast(new StringDecoder(Charset.forName("GBK")));
// 解码转String，注意调整自己的编码格式GBK、UTF-8
channel.pipeline().addLast(new StringEncoder(Charset.forName("GBK")));
// 在管道中添加我们自己的接收数据实现方法
channel.pipeline().addLast(new MyServerHandler());
}
}
package com.shu;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.socket.SocketChannel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 10:33
* @version: 1.0
*/
public class MyServerHandler extends ChannelInboundHandlerAdapter {
private Logger logger = LoggerFactory.getLogger(MyServerHandler.class);
/**
* 当客户端主动链接服务端的链接后，这个通道就是活跃的了。也就是客户端与服务端建立了通信通道并且可以传输数据
*/
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
SocketChannel channel = (SocketChannel) ctx.channel();
//通知客户端链接建立成功
String str = "通知客户端链接建立成功" + " " + new Date() + " " + channel.localAddress().getHostString() + "\r\n";
ctx.writeAndFlush(str);
}
/**
* 当客户端主动断开服务端的链接后，这个通道就是不活跃的。也就是说客户端与服务端的关闭了通信通道并且不可以传输数据
*/
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
logger.info("客户端断开链接{}", ctx.channel().localAddress().toString());
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
//接收msg消息{与上一章节相比，此处已经不需要自己进行解码}
logger.info(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + " 服务端接收到消息：" + msg);
//通知客户端链消息发送成功
String str = "服务端收到：" + new Date() + " " + msg + "\r\n";
ctx.writeAndFlush(str);
}
/**
* 抓住异常，当发生异常的时候，可以做一些相应的处理，比如打印日志、关闭链接
*/
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
ctx.close();
logger.info("异常信息：\r\n" + cause.getMessage());
}
}
package com.shu;
import io.netty.channel.ChannelFuture;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import java.net.InetSocketAddress;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 10:36
* @version: 1.0
*/
@SpringBootApplication
@ComponentScan("com.shu")
public class NettyApplication implements CommandLineRunner {
@Value("${netty.host}")
private String host;
@Value("${netty.port}")
private int port;
@Autowired
private NettyServer nettyServer;
public static void main(String[] args) {
SpringApplication.run(NettyApplication.class, args);
}
@Override
public void run(String... args) throws Exception {
InetSocketAddress address = new InetSocketAddress(host, port);
ChannelFuture channelFuture = nettyServer.bind(address);
Runtime.getRuntime().addShutdownHook(new Thread(() -> nettyServer.destroy()));
channelFuture.channel().closeFuture().syncUninterruptibly();
}
}
1.2 客户端
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import java.nio.charset.Charset;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 10:41
* @version: 1.0
*/
public class ApiTest {
public static void main(String[] args) {
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(workerGroup);
b.channel(NioSocketChannel.class);
b.option(ChannelOption.AUTO_READ, true);
b.handler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel channel) throws Exception {
// 日志打印
channel.pipeline().addLast(new LoggingHandler(LogLevel.INFO));
// 基于换行符号
channel.pipeline().addLast(new LineBasedFrameDecoder(1024));
// 解码转String，注意调整自己的编码格式GBK、UTF-8
channel.pipeline().addLast(new StringDecoder(Charset.forName("GBK")));
// 解码转String，注意调整自己的编码格式GBK、UTF-8
channel.pipeline().addLast(new StringEncoder(Charset.forName("GBK")));
// 在管道中添加我们自己的接收数据实现方法
channel.pipeline().addLast(new ChannelInboundHandlerAdapter() {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
//接收msg消息{与上一章节相比，此处已经不需要自己进行解码}
System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + " 客户端接收到消息：" + msg);
}
});
}
});
ChannelFuture f = b.connect("127.0.0.1", 7397).sync();
System.out.println(" client start done");
//向服务端发送信息
f.channel().writeAndFlush("你好，SpringBoot启动的netty服务端，“我的结尾是一个换行符，用于传输半包粘包处理”\r\n");
f.channel().writeAndFlush("你好，SpringBoot启动的netty服务端，“我的结尾是一个换行符，用于传输半包粘包处理”\r\n");
f.channel().writeAndFlush("你好，SpringBoot启动的netty服务端，“我的结尾是一个换行符，用于传输半包粘包处理”\r\n");
f.channel().writeAndFlush("你好，SpringBoot启动的netty服务端，“我的结尾是一个换行符，用于传输半包粘包处理”\r\n");
f.channel().writeAndFlush("你好，SpringBoot启动的netty服务端，“我的结尾是一个换行符，用于传输半包粘包处理”\r\n");
f.channel().closeFuture().syncUninterruptibly();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
workerGroup.shutdownGracefully();
}
}
}
1.3 测试
我们仔细来观察一下这个日志打印，并注意一下这些字节的意思
- 注册
客户端
服务端
- 客户端建立连接
- 服务端连接建立，通知客户端连接建立
看到这里我就很疑惑他到底是如何把我们的文件转换成16进制的？
通过代码我们知道我们传递的文字：通知客户端链接建立成功 Mon May 08 20:30:04 CST 2023 127.0.0.1 但是他是如何转换成16进制的，下面我们来具体分析一下？
前提知识?
- GBK的中文编码是双字节来表示的，英文编码是用ASC||码表示的，既用单字节表示。但GBK编码表中也有英文字符的双字节表示形式，所以英文字母可以有2中GBK表示方式。为区分中文，将其最高位都定成1。英文单字节最高位都为0。当用GBK解码时，若高字节最高位为0，则用ASC||码表解码；若高字节最高位为1，则用GBK编码表解码
- 至于UTF－8编码则是用以解决国际上字符的一种多字节编。码，它对英文使用8位（即一个字节），中文使用24位（三个字节）来编码。
分析
这里我们采用的是GBK编码，那我们咋看懂这些字节表示的啥，这里可能还需要一些基本知识进制的转成，1字节8bit ，有了基础知识我们再来分析，如上面说中文GBK两个字节表示一个中文，那么通这个中文对应的两个字节就是cd a8，那咋验证？
参考网站：GB2312简体中文编码表 - 常用参考表对照表 - 脚本之家在线工具
我们可以发现真是CDA8代表汉字通，这也解释我心中的疑惑，这里这是汉字，下面我们看一下字母
字母分析？
当用GBK解码时，若高字节最高位为0，则用ASC||码表解码；若高字节最高位为1，则用GBK编码表解码？
那啥是高字节与低字节?
存放最低的8位有效位的字节被称为最低有效位字节或低位字节，而存放最高的8位有效位的字节被称为最高有效位字节或高位字节。
高位字节 低位字节
↓------------------------------↓ ↓-----------------------------↓
15 14 13 12 11 10 9. 8. 7. 6. 5. 4. 3. 2. 1. 0.
参考链接：ASCII码一览表，ASCII码对照表
我们可以通过Ascll码表可以发现空格对应16进制的20
而M的十六进制：4D
相信进过上面的理解，应该这一看懂这段报文的理解，这也为了自己看懂协议有了会很好的铺垫，下面我们继续看服务端与客户端的连接过程
- 客户端收到消息，建立链接，可以进行消息的传递了
- 客户端写消息
- 服务端收消息
二 Netty实现简单的文件传输
文件传输在我们的实际开发中中非常常见，下面我们来个简单的案例
2.1 实体类
主要必须实现序列化
package com.shu.file01;
import lombok.Data;
import java.io.File;
import java.io.Serializable;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 20:28
* @version: 1.0
*/
@Data
public class FileResponse implements Serializable {
private long length;
private File file;
public FileResponse() {
}
public FileResponse(long length, File file) {
this.length = length;
this.file = file;
}
public long getLength() {
return length;
}
public File getFile() {
return file;
}
}
package com.shu.file01;
import lombok.Data;
import java.io.Serializable;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 20:27
* @version: 1.0
*/
@Data
public class FileRequest implements Serializable {
private String fileName;
public FileRequest() {
}
public FileRequest(String fileName) {
this.fileName = fileName;
}
public String getFileName() {
return fileName;
}
}
2.2 服务端
package com.shu.file01;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 19:57
* @version: 1.0
*/
@Component("fileServer")
public class FileServer {
private Logger logger = LoggerFactory.getLogger(FileServer.class);
/**
* 绑定端口
*
* @param port
* @return
*/
public void bind(int port) {
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap bootstrap = new ServerBootstrap()
.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline()
.addLast(new ObjectEncoder())
.addLast(new ObjectDecoder(Integer.MAX_VALUE, ClassResolvers.weakCachingConcurrentResolver(null)))
.addLast(new FileServerHandler());
}
});
ChannelFuture future = bootstrap.bind(port).sync();
future.channel().closeFuture().sync();
System.out.println("服务端启动成功，端口：" + port);
} catch (InterruptedException e) {
throw new RuntimeException(e);
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
package com.shu.file01;
import io.netty.channel.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.RandomAccessFile;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 20:19
* @version: 1.0
*/
public class FileServerHandler extends ChannelInboundHandlerAdapter {
private static final String FILE_PATH = "D:\\coreconfig.txt";
private Logger logger = LoggerFactory.getLogger(FileServerHandler.class);
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
super.channelActive(ctx);
logger.info("channelActive");
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
logger.info("channelRead");
if (msg instanceof FileRequest) {
FileRequest request = (FileRequest) msg;
if (request.getFileName().equals(FILE_PATH)) {
File file = new File(FILE_PATH);
if (file.exists()) {
RandomAccessFile raf = new RandomAccessFile(file, "r");
long length = raf.length();
FileResponse response = new FileResponse(length, file);
ctx.writeAndFlush(response);
ChannelFuture sendFileFuture = ctx.writeAndFlush(new DefaultFileRegion(raf.getChannel(), 0, length), ctx.newProgressivePromise());
sendFileFuture.addListener(new ChannelProgressiveFutureListener() {
@Override
public void operationComplete(ChannelProgressiveFuture future) throws Exception {
System.out.println("File transfer completed.");
raf.close();
}
@Override
public void operationProgressed(ChannelProgressiveFuture future, long progress, long total) throws Exception {
if (total < 0) {
System.err.println("File transfer progress: " + progress);
} else {
System.err.println("File transfer progress: " + progress + " / " + total);
}
}
});
} else {
System.err.println("File not found: " + FILE_PATH);
}
} else {
System.err.println("Invalid file name: " + request.getFileName());
}
}
}
}
2.3 客户端
package com.shu.file01;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 20:42
* @version: 1.0
*/
public class FileClient {
private static final int PORT = 8080;
private static final String HOST = "localhost";
private Logger logger = LoggerFactory.getLogger(FileClient.class);
private final EventLoopGroup parentGroup = new NioEventLoopGroup();
/**
* 连接服务端
*/
public void connect() {
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap bootstrap = new Bootstrap()
.group(group)
.channel(NioSocketChannel.class)
.option(ChannelOption.TCP_NODELAY, true)
.handler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline()
.addLast(new ObjectEncoder())
.addLast(new ObjectDecoder(ClassResolvers.weakCachingConcurrentResolver(null)))
.addLast(new FileClientHandler());
}
});
ChannelFuture future = bootstrap.connect(HOST, PORT).sync();
future.channel().closeFuture().sync();
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
group.shutdownGracefully();
}
}
}
package com.shu.file01;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import java.io.File;
import java.io.FileOutputStream;
import java.nio.channels.FileChannel;
/**
* @description:
* @author: shu
* @createDate: 2023/5/7 20:47
* @version: 1.0
*/
public class FileClientHandler extends ChannelInboundHandlerAdapter {
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
FileRequest request = new FileRequest("D:\\coreconfig.txt");
ctx.writeAndFlush(request);
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof FileResponse) {
FileResponse response = (FileResponse) msg;
File file = response.getFile();
long fileLength = response.getLength();
FileOutputStream fos = new FileOutputStream(file);
FileChannel channel = fos.getChannel();
// channel.transferFrom(channel, 0, fileLength);
System.out.println("File " + file.getName() + " received.");
} else {
System.err.println("Invalid response type: " + msg.getClass());
}
}
}
2.4 测试
这就是一个简单的测试吧，实际的开发中我们需要考虑很多，比如大文件的传输，断点续点，文件传输的加密等等系列问题，这个我正在研究中，以后再说