0 前言
在JAVA团队外部交互数据时，有几种罕用的办法，比方JAVA原生序列化办法、Json序列化办法、Protobuf序列化办法等，比照试验详见：几种序列化形式的性能比拟。
从比照试验可知protobuf性能最佳，因为其高效的序列化性能以及优良的跨平台能力，被广泛应用于跨平台之间的数据交互。但在不须要思考跨平台的数据交互时，protobuf的繁琐流程成了烦人的“污点”。
基于ptoro传输数据的个别流程是，先编写proto文件，再手动编译proto文件生成java类，而后实例化java类并填充数据，最初编译成二进制数据进行传输。其中编写及手动编译proto文件是个较繁琐的过程（比方简单我的项目中proto之间的互相援用），而且由proto生成的java类应用的是创建者模式（即Bulider模式），其实例化后的赋值过程与我的项目历史代码格调不统一，为带来较大的改变。
为解决这个问题，本文将介绍百度团队开发的Jprotobuf工具，并总结应用过程中的注意事项，以及通过试验验证其与谷歌团队开发的Protobuf性能的一致性。
1 Jprotobuf介绍
1.1 定义
jprotobuf是针对JAVA程序开发一套繁难类库，目标是简化JAVA语言对protobuf类库的应用。应用jprotobuf能够无需再去理解proto文件操作与语法，间接应用JAVA注解定义字段类型即可。
github地址：https://github.com/jhunters/j...
1.2 原理
jprotobuf工作原理如下：
- 扫描类上的注解的信息，进行剖析(与protobuf读取proto文件进行剖析过程类似)
- 依据注解剖析的后果，动静生成java代码进行protobuf序列化与反序列化的性能实现
- 应用JDK6及以上的 code compile API进行编译后加载到classloader
1.3 性能
jprotobuf 次要性能耗费在扫描类上注解，动静生成代码编译的过程。在执行序列化与反序列化的过程中，简直与protobuf生成的代码效率等同。如果应用预编译插件，则无需在运行中进行代码生成与编译，效率更高。
1.4 特点
- 无需编写proto文件及繁琐的手工编译过程，反对基于POJO对象的注解形式，方便快捷。
反对protobuf所有类型，包含对象嵌套，数组，枚举类型 - 提供依据proto文件，动静生成代理对象，可省去POJO对象的编写工作。
残缺反对proto文件所有性能，包含内联对象，匿名对象，枚举类型 - 提供从POJO对象的注解形式主动生成proto文件的性能， 不便proto形容文件的治理与保护
- 提供预编译Maven插件，进一步晋升运行性能
- 新增预编译gradle插件
- 2.x版本。 反对TimeStamp类型, 与原生protobuf保持一致。 反对Date类型，应用long类型传递 docs
2 Jprotobuf装置
maven代码如下：
<!-- jprotobuf --><dependency> <groupId>com.baidu</groupId> <artifactId>jprotobuf</artifactId> <version>2.4.5</version></dependency><dependency> <groupId>com.baidu</groupId> <artifactId>jprotobuf-precompile-plugin</artifactId> <version>2.2.2</version></dependency>3 案例数据
测试思路：通过各自的办法构建雷同的测试数据，进行序列化和反序列比拟两者之间的差别。
注意事项：设计的案例数据尽量蕴含所有的数据类型。
3.1 Protobuf数据定义
组织构造如图，其中data依赖student，student依赖person，teacher作为第三方扩大包，用于测试扩大性能。
data.proto代码如下：
// Google Protocol Buffers Version 3.syntax = "proto3";// Package name.package prcticeProto.messages;// Options for code generation.option java_package = "learnProto.practiceTest.protoModel";option java_outer_classname = "SchoolModel";option java_multiple_files = true;// import packagesimport "google/protobuf/any.proto";import "practiceProto/categories/student.proto";message School { message Location{ string name=1; uint32 id=2; } Location schoolLocation = 1; bool isOpen =2; repeated categories.Student allStudents = 3; google.protobuf.Any extend =4;}student.proto代码如下：
// Google Protocol Buffers Version 3.syntax = "proto3";// Package name.package prcticeProto.categories;// Options for code generation.option java_package = "learnProto.practiceTest.protoModel";option java_outer_classname = "StudentModel";option java_multiple_files = true;// import packagesimport "practiceProto/base/person.proto";message Student { base.Person baseInfo = 1; fixed32 calssId = 2; sint32 score = 3;}person.proto代码如下：
// Google Protocol Buffers Version 3.syntax = "proto3";// Package name.package prcticeProto.base;// Options for code generation.option java_package = "learnProto.practiceTest.protoModel";option java_outer_classname = "PersonModel";option java_multiple_files = true;message Person{ message Location{ string placeName=1; uint64 placeId=2; } enum Gender{ man=0; woman=1; } string name = 1; int32 age=2; Gender gender=3; float height=4; double weight=5; Location location=6;}teacher.proto代码如下：
// Google Protocol Buffers Version 3.syntax = "proto3";// Options for code generation.option java_package = "learnProto.practiceTest.protoModel";option java_outer_classname = "TeacherModel";option java_multiple_files = true;message Teacher{ string name = 1; int32 age=2;}3.2 Jprotobuf数据定义
组织构造如图所示。
Jprotobuf的定义语法详见：https://github.com/jhunters/j...
school代码如下：
package learnProto.jprotobuf.model;import com.baidu.bjf.remoting.protobuf.Any;import com.baidu.bjf.remoting.protobuf.FieldType;import com.baidu.bjf.remoting.protobuf.annotation.Protobuf;import com.baidu.bjf.remoting.protobuf.annotation.ProtobufClass;import java.util.List;@ProtobufClasspublic class School { @ProtobufClass public static class Location{ @Protobuf(fieldType= FieldType.STRING, order=1) private String name; @Protobuf(fieldType= FieldType.UINT32, order=2) private Integer id; public String getName() { return name; } public Location setName(String name) { this.name = name; return this; } public Integer getId() { return id; } public Location setId(Integer id) { this.id = id; return this; } } @Protobuf(fieldType= FieldType.OBJECT, order=1) private Location schoolLocation; @Protobuf(fieldType= FieldType.BOOL, order=2) private Boolean isOpen; @Protobuf(fieldType= FieldType.OBJECT, order=3) private List<Student> allStudents; @Protobuf(fieldType = FieldType.OBJECT,order = 4) private Any extend; public Any getExtend() { return extend; } public School setExtend(Any extend) { this.extend = extend; return this; } public Location getSchoolLocation() { return schoolLocation; } public School setSchoolLocation(Location schoolLocation) { this.schoolLocation = schoolLocation; return this; } public Boolean getOpen() { return isOpen; } public School setOpen(Boolean open) { isOpen = open; return this; } public List<Student> getAllStudents() { return allStudents; } public School setAllStudents(List<Student> allStudents) { this.allStudents = allStudents; return this; }}student代码如下：
package learnProto.jprotobuf.model;import com.baidu.bjf.remoting.protobuf.FieldType;import com.baidu.bjf.remoting.protobuf.annotation.Protobuf;import com.baidu.bjf.remoting.protobuf.annotation.ProtobufClass;@ProtobufClasspublic class Student{ @Protobuf(fieldType=FieldType.OBJECT, order=1) private Person baseInfo; @Protobuf(fieldType=FieldType.FIXED32, order=2) private Integer calssId; @Protobuf(fieldType=FieldType.SINT32, order=3) private Integer score; public Person getBaseInfo() { return baseInfo; } public Student setBaseInfo(Person baseInfo) { this.baseInfo = baseInfo; return this; } public Integer getCalssId() { return calssId; } public Student setCalssId(Integer calssId) { this.calssId = calssId; return this; } public Integer getScore() { return score; } public Student setScore(Integer score) { this.score = score; return this; }}person代码如下：
package learnProto.jprotobuf.model;import com.baidu.bjf.remoting.protobuf.FieldType;import com.baidu.bjf.remoting.protobuf.annotation.Protobuf;import com.baidu.bjf.remoting.protobuf.annotation.ProtobufClass;@ProtobufClasspublic class Person { @ProtobufClass public enum Gender { MAN(0),WOMAN(1); @Protobuf(fieldType= FieldType.INT32, order=1) private final Integer value; Gender(Integer value) { this.value = value; } public Integer toValue() { return this.value; } public Integer value() { return toValue(); } } @ProtobufClass public static class Location{ @Protobuf(fieldType= FieldType.STRING, order=1) private String placeName; @Protobuf(fieldType= FieldType.UINT64, order=2) private Long placeId; public String getPlaceName() { return placeName; } public Location setPlaceName(String placeName) { this.placeName = placeName; return this; } public Long getPlaceId() { return placeId; } public Location setPlaceId(Long placeId) { this.placeId = placeId; return this; } } @Protobuf(fieldType= FieldType.STRING, order=1) private String name; @Protobuf(fieldType= FieldType.INT32, order=2) private Integer age; @Protobuf(fieldType= FieldType.ENUM, order=3) private Gender gender; @Protobuf(fieldType= FieldType.FLOAT, order=4) private Float height; @Protobuf(fieldType= FieldType.DOUBLE, order=5) private Double weight; @Protobuf(fieldType= FieldType.OBJECT, order=6) private Location personLocation; public String getName() { return name; } public Person setName(String name) { this.name = name; return this; } public Integer getAge() { return age; } public Person setAge(Integer age) { this.age = age; return this; } public Gender getGender() { return gender; } public Person setGender(Gender gender) { this.gender = gender; return this; } public Float getHeight() { return height; } public Person setHeight(Float height) { this.height = height; return this; } public Double getWeight() { return weight; } public Person setWeight(Double weight) { this.weight = weight; return this; } public Location getPersonLocation() { return personLocation; } public Person setPersonLocation(Location personLocation) { this.personLocation = personLocation; return this; }}teacher代码如下：
package learnProto.jprotobuf.model;import com.baidu.bjf.remoting.protobuf.annotation.ProtobufClass;@ProtobufClasspublic class Teacher { private Integer id; private String name; public Integer getId() { return id; } public Teacher setId(Integer id) { this.id = id; return this; } public String getName() { return name; } public Teacher setName(String name) { this.name = name; return this; }}4 案例测试
4.1 根本数据类型测试
public class jprotobufTest { public static void writeFileByte(byte[] b,String path) { File file = new File(path); long size = file.length(); try (FileOutputStream fos = new FileOutputStream(file)) { fos.write(b); fos.flush(); } catch (IOException e) { e.printStackTrace(); } } public static byte[] readFileByte(String path) { File file = new File(path); long size = file.length(); byte[] b = new byte[(int) size]; try (InputStream fis = new FileInputStream(file)) { if (fis.read(b) < 0) { return null; } } catch (IOException e) { e.printStackTrace(); } return b; } public void protobuff(String path){ // 实例化 learnProto.practiceTest.protoModel.Person.Builder builderPerson = learnProto.practiceTest.protoModel.Person.newBuilder().setAge(10).setGender(learnProto.practiceTest.protoModel.Person.Gender.woman).setName("Tom").setHeight(100.00f).setWeight(100.00d).setLocation( learnProto.practiceTest.protoModel.Person.Location.newBuilder().setPlaceId(123l).setPlaceName("hubei") ); learnProto.practiceTest.protoModel.School school = learnProto.practiceTest.protoModel.School.newBuilder() .setIsOpen(true) .setSchoolLocation(learnProto.practiceTest.protoModel.School.Location.newBuilder().setId(123).setName("hubei")) .addAllStudents(Student.newBuilder().setBaseInfo(builderPerson).setCalssId(10).setScore(-1)) .addAllStudents(Student.newBuilder().setBaseInfo(builderPerson).setCalssId(10).setScore(1)) .build(); try { // 序列化 byte[] bytes = school.toByteArray(); writeFileByte(bytes,path); System.out.println("protobuf序列化后的数据：" + Arrays.toString(bytes)+",字节个数："+bytes.length); //反序列化 byte[] bytes1 = readFileByte(path); learnProto.practiceTest.protoModel.School parseFrom = learnProto.practiceTest.protoModel.School.parseFrom(bytes1); } catch (InvalidProtocolBufferException e) { e.printStackTrace(); } } public void jprotobuf(String path){ // 实例化 Person person = new Person().setAge(10).setGender(Person.Gender.MAN).setName("Tom").setHeight(100.00f).setWeight(100.00d).setPersonLocation( new Person.Location().setPlaceId(123l).setPlaceName("hubei") ); ArrayList<learnProto.jprotobuf.model.Student> studentArrayList = new ArrayList<>(); studentArrayList.add(new learnProto.jprotobuf.model.Student().setCalssId(10).setScore(-1).setBaseInfo(person)); studentArrayList.add(new learnProto.jprotobuf.model.Student().setCalssId(10).setScore(1).setBaseInfo(person)); School sch = new School().setOpen(true).setAllStudents(studentArrayList).setSchoolLocation(new School.Location().setId(123).setName("hubei")); try { // 序列化 Codec<School> simpleTypeCodec = ProtobufProxy.create(School.class); byte[] b = simpleTypeCodec.encode(sch); writeFileByte(b,path); System.out.println("Jprotobuf序列化后的数据：" + Arrays.toString(b)+",字节个数："+b.length); // 反序列化 byte[] bytes =readFileByte(path); School newStt = simpleTypeCodec.decode(bytes); } catch (IOException e) { e.printStackTrace(); } } @Test public void test(){ protobuff("C:UsersadminDesktopProtodemo.pack"); jprotobuf("C:UsersadminDesktopJprotodemo.pack"); }}运行后果：
protobuf序列化后的数据：[10, 9, 10, 5, 104, 117, 98, 101, 105, 16, 123, 16, 1, 26, 43, 10, 34, 10, 3, 84, 111, 109, 16, 10, 24, 1, 37, 0, 0, -56, 66, 41, 0, 0, 0, 0, 0, 0, 89, 64, 50, 9, 10, 5, 104, 117, 98, 101, 105, 16, 123, 21, 10, 0, 0, 0, 24, 1, 26, 43, 10, 34, 10, 3, 84, 111, 109, 16, 10, 24, 1, 37, 0, 0, -56, 66, 41, 0, 0, 0, 0, 0, 0, 89, 64, 50, 9, 10, 5, 104, 117, 98, 101, 105, 16, 123, 21, 10, 0, 0, 0, 24, 2],字节个数：103Jprotobuf序列化后的数据：[10, 9, 10, 5, 104, 117, 98, 101, 105, 16, 123, 16, 1, 26, 43, 10, 34, 10, 3, 84, 111, 109, 16, 10, 24, 0, 37, 0, 0, -56, 66, 41, 0, 0, 0, 0, 0, 0, 89, 64, 50, 9, 10, 5, 104, 117, 98, 101, 105, 16, 123, 21, 10, 0, 0, 0, 24, 1, 26, 43, 10, 34, 10, 3, 84, 111, 109, 16, 10, 24, 0, 37, 0, 0, -56, 66, 41, 0, 0, 0, 0, 0, 0, 89, 64, 50, 9, 10, 5, 104, 117, 98, 101, 105, 16, 123, 21, 10, 0, 0, 0, 24, 2],字节个数：103试验表明，Jprotobuf的序列化办法与Protobuf统一，能够放心使用。
4.2 第三方扩大测试
@Testpublic void schooltest() throws IOException { // jproto Any any = Any.pack(new Teacher()); School person = new School().setExtend(any); Codec<School> simpleTypeCodec = ProtobufProxy.create(School.class); try { // 序列化 byte[] b = simpleTypeCodec.encode(person); writeFileByte(b,"C:UsersadminDesktopjproto.pack"); System.out.println("jproto序列化后的数据：" + Arrays.toString(b)+",字节个数："+b.length); // 反序列化 byte[] bytes =readFileByte("C:UsersadminDesktopjproto.pack"); School newStt = simpleTypeCodec.decode(bytes); } catch (IOException e) { e.printStackTrace(); } // proto com.google.protobuf.Any any1 = com.google.protobuf.Any.pack(learnProto.practiceTest.protoModel.Teacher.newBuilder().build()); learnProto.practiceTest.protoModel.School builderPerson = learnProto.practiceTest.protoModel.School.newBuilder() .setExtend(any1) .build(); try { // 序列化 String path="C:UsersadminDesktopProtodemo.pack"; byte[] bytes = builderPerson.toByteArray(); writeFileByte(bytes,path); System.out.println("protobuf序列化后的数据：" + Arrays.toString(bytes)+",字节个数："+bytes.length); //反序列化 byte[] bytes1 = readFileByte(path); learnProto.practiceTest.protoModel.School parseFrom = learnProto.practiceTest.protoModel.School.parseFrom(bytes1); } catch (InvalidProtocolBufferException e) { e.printStackTrace(); }}运行后果：
jproto序列化后的数据：[34, 58, 10, 54, 116, 121, 112, 101, 46, 103, 111, 111, 103, 108, 101, 97, 112, 105, 115, 46, 99, 111, 109, 47, 108, 101, 97, 114, 110, 80, 114, 111, 116, 111, 46, 106, 112, 114, 111, 116, 111, 98, 117, 102, 46, 109, 111, 100, 101, 108, 46, 84, 101, 97, 99, 104, 101, 114, 18, 0],字节个数：60protobuf序列化后的数据：[34, 29, 10, 27, 116, 121, 112, 101, 46, 103, 111, 111, 103, 108, 101, 97, 112, 105, 115, 46, 99, 111, 109, 47, 84, 101, 97, 99, 104, 101, 114],字节个数：31试验表明，Jprotobuf的扩大性能能够失常应用，但其机制可能与protobuf有差别。
5 应用总结
1、字段的注解@Protobuf，能够不写，不写的状况下依照默认类型，order依照书写的程序；也能够写，自定义类型和order。但肯定不要有的字段写，有的字段不写，order会乱！
2、 构建的@ProtobufClass不要带有有参结构器，实例化时也不能带参数结构。只能无参结构后，通过set或add赋值（与proto的实例化标准统一）。
3、 能够调用_getIDL_取得IDL，即proto文件，但所有的嵌套构造都被拆开成了独自的构造。
4、 setter的返回类型能够设定为类自身，从而实现链式。如图：
5、 定义根本数据类型的数据时，要用包装类。比方对于整型，不要写int，而应该写INTGER，如上图中的id，如果设置为int，零碎默认初始化了id=0，即便没有赋值，该数值在序列化时会被写入数据；如果设置为INTGER，没有赋值，不会被写入序列化的字节序中。（此处与proto不同，proto中字段设定值等于默认值时，序列化时数据不会被写入，反序列化后所有没被赋值的字段都被赋对应类型的默认值；而jprotobuf齐全依照用户输出的志愿，序列化之前赋值什么，序列化时就有什么，反序列化时也对应有什么，如果字段没被赋值，反序列化后为null，enum为第一个枚举值）。
6、反序列化应用时留神：没被赋值的字段反序列化后值为null，并非默认值。
7、设定了多个字段，有些没有赋值，并不会影响数据序列化后的大小。
6 参考文献
[1] 几种序列化形式的性能比拟
[2] https://github.com/jhunters/j...
[3] https://github.com/jhunters/j...