一般在使用netty时，数据传输的时候都会选择对传输的数据进行编解码，编码后的数据变小， 有利于在有限的带宽下传输更多的数据。
由于java本身序列化的缺点较多（无法跨语言，序列化后的码流太大，序列化的性能太低等），业界主流的编解码框架主要有如下三个:
- google的protobuf
- facebook的thrift
- jboss的marshalling
今天我们简单介绍一下netty结合google的protobuf框架进行数据的编解码。
1. 什么是protobuf？
protobuf全称是google protocol buffers, 它是谷歌公司开源的一个序列化框架。
它将数据结构以.proto文件进行描述，通过代码生成工具可以生成对应数据结构的pojo对象和protobuf相关的方法和属性。
它的特点如下：
- 结构化数据存储格式
- 高效的编解码性能
- 语言无关、平台无关、扩展性好
- 官方支持多个语言（java，c++，python，c#等）
2. 下载安装
protobuf已经托管在github上，可以在页面下载，本案例使用的是v3.6（要下载后缀为-win32.zip的）。
下载后，将压缩包进行解压。这里主要用到bin目录下的protoc.exe。
3. 定义好proto文件
subscribereq.proto
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
// 区分不同的protobuf版本，必须有
syntax = "proto2";
package netty;
// 生成的目标类的包路径
option java_package = "cn.ddlover.nettystudy.protobuf";
// 生成的目标类的名字
option java_outer_classname = "subscribereqproto";
message subscribereq{
required int32 subreqid = 1;
required string username = 2;
required string productname = 3;
repeated string address = 4;
}
|
subscriberesp.proto
?
|
1
2
3
4
5
6
7
8
9
10
11
|
syntax = "proto2";
package netty;
option java_package = "cn.ddlover.nettystudy.protobuf";
option java_outer_classname = "subscriberespproto";
message subscriberesp{
required int32 subreqid = 1;
required int32 respcode = 2;
required string desc = 3;
}
|
此时项目结构如下
重点关注一下两个proto文件的位置，是位于项目的根路径下
4. 分别执行以下命令
d:\\xhb\\protoc-3.6.1-win32\\bin\\protoc.exe –java_out=.\\src\\main\\java subscriberesp.proto
d:\\xhb\\protoc-3.6.1-win32\\bin\\protoc.exe –java_out=.\\src\\main\\java subscribereq.proto
这里需要把protoc.exe的位置换成自己的， –java_out命令设置的是proto文件中java_package指令的父目录。
5. 此时项目结构如下
下面开始代码方面的开发，
1. 先贴一波maven的配置
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
<?xml version="1.0" encoding="utf-8"?>
<project xmlns="http://maven.apache.org/pom/4.0.0"
xmlns:xsi="http://www.w3.org/2001/xmlschema-instance"
xsi:schemalocation="http://maven.apache.org/pom/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelversion>4.0.0</modelversion>
<groupid>cn.ddlover</groupid>
<artifactid>nettystudy</artifactid>
<version>1.0-snapshot</version>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!-- https://mvnrepository.com/artifact/io.netty/netty-all -->
<dependency>
<groupid>io.netty</groupid>
<artifactid>netty-all</artifactid>
<version>4.1.33.final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.google.protobuf/protobuf-java -->
<dependency>
<groupid>com.google.protobuf</groupid>
<artifactid>protobuf-java</artifactid>
<version>3.6.1</version>
</dependency>
<dependency>
<groupid>org.projectlombok</groupid>
<artifactid>lombok</artifactid>
<version>1.18.4</version>
</dependency>
</dependencies>
</project>
|
2. 这里贴上完整代码的项目结构
3.subreqserver.java
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
import cn.ddlover.nettystudy.handler.subreqserverhandler;
import cn.ddlover.nettystudy.protobuf.subscribereqproto;
import io.netty.bootstrap.serverbootstrap;
import io.netty.channel.channelfuture;
import io.netty.channel.channelinitializer;
import io.netty.channel.channeloption;
import io.netty.channel.eventloopgroup;
import io.netty.channel.nio.nioeventloopgroup;
import io.netty.channel.socket.socketchannel;
import io.netty.channel.socket.nio.nioserversocketchannel;
import io.netty.handler.codec.protobuf.protobufdecoder;
import io.netty.handler.codec.protobuf.protobufencoder;
import io.netty.handler.codec.protobuf.protobufvarint32framedecoder;
import io.netty.handler.codec.protobuf.protobufvarint32lengthfieldprepender;
import io.netty.handler.logging.loglevel;
import io.netty.handler.logging.logginghandler;
/**
* protobuf版本图书订购代码
*/
public class subreqserver {
private static final int port = 8080;
public static void main(string[] args) {
bind(port);
}
private static void bind(int port) {
eventloopgroup bossgroup = new nioeventloopgroup();
eventloopgroup workergroup = new nioeventloopgroup();
serverbootstrap b = new serverbootstrap();
try {
b.group(bossgroup, workergroup)
.channel(nioserversocketchannel.class)
.option(channeloption.so_backlog, 100)
.handler(new logginghandler(loglevel.info))
.childhandler(new channelinitializer<socketchannel>() {
@override
protected void initchannel(socketchannel socketchannel) throws exception {
// 半包处理
socketchannel.pipeline().addlast(new protobufvarint32framedecoder());
socketchannel.pipeline().addlast(new protobufdecoder(subscribereqproto.subscribereq.getdefaultinstance()));
socketchannel.pipeline().addlast(new protobufvarint32lengthfieldprepender());
socketchannel.pipeline().addlast(new protobufencoder());
socketchannel.pipeline().addlast(new subreqserverhandler());
}
});
channelfuture future = b.bind(port).sync();
future.channel().closefuture().sync();
} catch (interruptedexception e) {
e.printstacktrace();
}finally {
bossgroup.shutdowngracefully();
workergroup.shutdowngracefully();
}
}
}
|
4.subreqserverhandler.java
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
|
import cn.ddlover.nettystudy.protobuf.subscribereqproto;
import cn.ddlover.nettystudy.protobuf.subscriberespproto;
import io.netty.channel.channelhandlercontext;
import io.netty.channel.channelinboundhandleradapter;
public class subreqserverhandler extends channelinboundhandleradapter {
@override
public void channelread(channelhandlercontext ctx, object msg) throws exception {
subscribereqproto.subscribereq req = (subscribereqproto.subscribereq)msg;
if ("张三".equals(req.getusername())) {
system.out.println("server accept clietn subscribe req : ["+req.tostring()+"]");
ctx.writeandflush(resp(req.getsubreqid()));
}
}
private subscriberespproto.subscriberesp resp(int subreqid) {
subscriberespproto.subscriberesp.builder builder = subscriberespproto.subscriberesp.newbuilder();
builder.setsubreqid(subreqid);
builder.setrespcode(0);
builder.setdesc("netty书籍下单成功，3天后将会送到你的住处");
return builder. build();
}
@override
public void exceptioncaught(channelhandlercontext ctx, throwable cause) throws exception {
cause.printstacktrace();
ctx.close();
}
}
|
5.subreqclient.java
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
import cn.ddlover.nettystudy.handler.subreqclienthandler;
import cn.ddlover.nettystudy.protobuf.subscriberespproto;
import io.netty.bootstrap.bootstrap;
import io.netty.channel.channelfuture;
import io.netty.channel.channelinitializer;
import io.netty.channel.channeloption;
import io.netty.channel.eventloopgroup;
import io.netty.channel.nio.nioeventloopgroup;
import io.netty.channel.socket.socketchannel;
import io.netty.channel.socket.nio.niosocketchannel;
import io.netty.handler.codec.protobuf.protobufdecoder;
import io.netty.handler.codec.protobuf.protobufencoder;
import io.netty.handler.codec.protobuf.protobufvarint32framedecoder;
import io.netty.handler.codec.protobuf.protobufvarint32lengthfieldprepender;
public class subreqclient {
private static final string host = "localhost";
private static final int port = 8080;
public static void main(string[] args) {
connect(host, port);
}
private static void connect(string host, int port) {
eventloopgroup group = new nioeventloopgroup();
bootstrap b = new bootstrap();
try {
b.group(group).channel(niosocketchannel.class)
.option(channeloption.tcp_nodelay, true)
.handler(new channelinitializer<socketchannel>() {
@override
protected void initchannel(socketchannel socketchannel) throws exception {
// 半包处理
socketchannel.pipeline().addlast(new protobufvarint32framedecoder());
socketchannel.pipeline().addlast(new protobufdecoder(subscriberespproto.subscriberesp.getdefaultinstance()));
socketchannel.pipeline().addlast(new protobufvarint32lengthfieldprepender());
socketchannel.pipeline().addlast(new protobufencoder());
socketchannel.pipeline().addlast(new subreqclienthandler());
}
});
channelfuture f = b.connect(host, port).sync();
f.channel().closefuture().sync();
} catch (interruptedexception e) {
e.printstacktrace();
}finally {
group.shutdowngracefully();
}
}
}
|
6.subreqclienthandler.java
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
import cn.ddlover.nettystudy.protobuf.subscribereqproto;
import io.netty.channel.channelhandlercontext;
import io.netty.channel.channelinboundhandleradapter;
import java.util.arraylist;
import java.util.list;
public class subreqclienthandler extends channelinboundhandleradapter {
@override
public void channelactive(channelhandlercontext ctx) throws exception {
for (int i =0;i<10;i++) {
ctx.write(subreq(i));
}
ctx.flush();
}
private subscribereqproto.subscribereq subreq(int i) {
subscribereqproto.subscribereq.builder builder = subscribereqproto.subscribereq.newbuilder();
builder.setsubreqid(i);
builder.setusername("张三");
builder.setproductname("netty book");
list<string> address = new arraylist<>();
address.add("nanjing yuhuatai");
address.add("beijing liulichang");
address.add("shenzhen hongshulin");
builder.addalladdress(address);
return builder.build();
}
@override
public void channelread(channelhandlercontext ctx, object msg) throws exception {
system.out.println("receive server response : ["+ msg +"]");
}
@override
public void exceptioncaught(channelhandlercontext ctx, throwable cause) throws exception {
cause.printstacktrace();
ctx.close();
}
}
|
代码部分到此就结束了，然后分别运行subreqserver和subreqclient， 就可以发现运行成功了。
这里要注意的事，调用tostring的时候，中文在控制台打印的是字节，而调用对应属性的getter方法的时候，是可以做中文的判断的，显然这里protobuf的tostring没有被修改好呀。
当然，我们也可以发现，netty本身已经封装好了对谷歌的protobuf的支持。netty还是很强大的。
到此这篇关于netty结合protobuf进行编解码的文章就介绍到这了,更多相关netty结合protobuf编解码内容请搜索快网idc以前的文章或继续浏览下面的相关文章希望大家以后多多支持快网idc！
原文链接：https://blog.csdn.net/qq_33227649/article/details/86689658
相关文章
猜你喜欢
