中間件復(fù)習(xí)筆記

2022年-n月-13日

第一章INTRO

1.概念

ii.一類獨(dú)立的系統(tǒng)軟件和服務(wù)程序

iii.Aclassofstandalonesystem-levelsoftwareandservicesprocedures

iv.在操作系統(tǒng)的頂部

v.WorkingonthetopofOS

vi管理計(jì)算機(jī)資源和網(wǎng)絡(luò)

vii.Managingcomputationalresourcesandnetworkcommunications

viii.支持分布式通信

ix.Supportingdistributedapps

Application

Middleware

OperatingIOperating

SystemISystem

HARDWAREIHARDWARE

b）功能

i.在異構(gòu)的網(wǎng)絡(luò)環(huán)境中，涉及到跨連通性和可操作問題中

ii.供應(yīng)統(tǒng)一的合同和接口

iii.Providingstandardizedinterfacesandprotocols

iv.隱蔽實(shí)現(xiàn)細(xì)節(jié)

v.Hidingimplementationdetails

vi.提高程序的可移植性

vii.Increasingtheportabilityofapps

viii.放置于操作系統(tǒng)和數(shù)據(jù)庫管理系統(tǒng)的頂部

ix.為高級(jí)應(yīng)用的開發(fā)和執(zhí)行供應(yīng)環(huán)境

x.Providingenvironmentsfortheexecutionanddevelopmentofhigher-levelapps

xi.幫助軟件工程師敏捷高效地開發(fā)和集成簡單的分布式軟件

xii.Assistingsoftwareengineersinflexiblyandefficientlydevelopingandintegrating

complexdistributedsoftware

c）中間件進(jìn)展的主要因素

i.隱蔽異構(gòu)型Hidingheterogeneity

1.硬件異構(gòu)hardwareheterogeneity

2.操作系統(tǒng)異構(gòu)OSheterogeneity

3.數(shù)據(jù)庫異構(gòu)databaseheterogeneity

ii.支才寺可操彳乍'性supportinginter-operability

1.不同的平臺(tái)differentplatforms

2.不同的網(wǎng)絡(luò)合同differentnetworkprotocols

3.不同的通信機(jī)制differentcommunicationmechanisms

iiL提高軟件的復(fù)用率improvingefficiencyandqualityofsoftwaredevelopment

d）主要類別

i.遠(yuǎn)程過程調(diào)用中間件RPCremoteprocedurecallmiddleware

ii.對(duì)象懇求代理中間件ORBobjectrequestbrokersmiddleware

iii.面對(duì)信息中間件MOMmessage-orientedmiddleware

iv.數(shù)據(jù)庫訪問中間件DAMdatabaseaccessmiddleware

v.事務(wù)處理中間件TPMtransactionprocessingmiddleware

第二章RMI

a）對(duì)象懇求代理ORB

i.供應(yīng)一個(gè)框架，使得遠(yuǎn)程對(duì)象可以在網(wǎng)絡(luò)中以同樣的方式使用在網(wǎng)絡(luò)中的本地對(duì)象

ii.Providingaframeworkwhereremoteobjectcanuselocalobjectsinthe

samewayoverthenetwork

iii.當(dāng)對(duì)象在客戶端和服務(wù)器之間傳遞時(shí)，供應(yīng)功能的編組和解組的功能

iv.Providingfunctionalitiesformarshallingandunmarshalingwhenobjectsare

transmittedbetweenclientsandservers.

v.客戶端和服務(wù)器之間的傳輸隱蔽實(shí)現(xiàn)的細(xì)節(jié)，這使得開發(fā)人員能夠有效地實(shí)現(xiàn)分布

式應(yīng)用程序，而無需面對(duì)簡單的底層操作系統(tǒng)和網(wǎng)絡(luò)通信

vi.Hidingtheimplementationdetails,whichenabledeveloperstoimplement

distributedappsefficientlywithoutfacingthecomplexunderlyingoperating

systemsandnetworkcommunications

b)JAVARMI的概述

i.用java編寫分布式對(duì)象

ii.Writingdistributedobjectsusingjava

iii.直接用java對(duì)象來為分布式計(jì)算機(jī)建模

iv.Simpleanddirectmodelfordistributedcomputationwithjavaobjects

v.以java為中心，由此帶來了平安性和分布式計(jì)算的可移植性

vi.Centeredaroundjava,thusbringingthepowerofJavaSafetyandportability

todistributedcomputing

vii.行為可以被轉(zhuǎn)移動(dòng)

viii.Behaviorcanberemoved

ix.通過JNI可以鏈接到現(xiàn)有的遺留系統(tǒng)

x.ConnectedexistedlegacysystembyJNI

xi.通過JDBC可以鏈接到關(guān)系數(shù)據(jù)庫

xii.ConnectedrelationaldatabasebyJDBC

c）優(yōu)點(diǎn)

i.面對(duì)對(duì)象。0

1.全部的對(duì)象可以作為參數(shù)和返回值

2.Allobjectscanbeargumentsandreturnvalues

ii.可移動(dòng)性行為mobilebehavior

1.類的實(shí)現(xiàn)可以被移植

2.Theimplementationsofclasscanbemoved

iii.設(shè)計(jì)模式designpatterns

1.傳遞性對(duì)象確保了面對(duì)對(duì)象技術(shù)的全功率

2.Passingobjectsensurethefullpowerof00techs

iv.平安Secure

1.基于JAVA的平安機(jī)制：平安經(jīng)理

2.BasedonJAVAsecuritymechanismssecuritymanager

d）次優(yōu)點(diǎn)

i.非常簡潔開發(fā)，使用，維護(hù)

ii.Easytowrite,useandmaintain

iii.可以與現(xiàn)存的遺留系統(tǒng)鏈接canconnectwithexistedlegacysystem

1.RMI/JNI,RMI/JDBC

iv.開發(fā)一次，可以在任何地方運(yùn)行writeonce,canbeuseanywhere

1.100%移植至IJ任何JVM100%portabletoanyJVM

v.分布式垃圾收集distributedgarbagecollection

vi.并行計(jì)算parallelcomputing

1.多線程，并行處理MUTI-threadconcurrentprocessing

e）架構(gòu)architecture

i.存根stub

1.編組參數(shù)，發(fā)送調(diào)用

2.Marshalingarguments,sendinginvocation

ii.骨骼skeleton

1.解封參數(shù)，調(diào)用服務(wù)器來實(shí)現(xiàn)

2.Unmarshalingarguments,invokingserver*simplementation

f)RMI的分布式應(yīng)用

i.定位遠(yuǎn)程對(duì)象locateremoteobjects

ii.與遠(yuǎn)程對(duì)象通信communicatewithremoteobjects

iii.為被傳遞的對(duì)象加載類定義loaddefinitionofclassesthatarepassedaround

g)遠(yuǎn)程接口，對(duì)象和方法remoteinterface,objectsandmethods

i.通過實(shí)現(xiàn)一個(gè)具有以下特點(diǎn)的遠(yuǎn)程接口來實(shí)現(xiàn)對(duì)象遠(yuǎn)程化Anobjectsbecomes

remotebyimplementingaremoteinterfacewithfollowingcharacteristics

1.一個(gè)遠(yuǎn)程接口擴(kuò)展了接口oneremoteinterfaceextendsaninterface

a)

2.接口的每一^?方法都有事先聲明everymethodsoftheinterfacehasbeen

declared

a)Java.rmi.RemoteExceptioninitsthrowsclause

h）主要步驟mainsteps

i.定義遠(yuǎn)程接口definetheremoteinterface

1.指明可以遠(yuǎn)程調(diào)用的方法specifyingthemethodsthatcanbeinvoked

remotely

ii.實(shí)施遠(yuǎn)程對(duì)象implementingtheremoteobjects

1.可能包括本地接口/方法的實(shí)現(xiàn)mayincludetheimplementationoflocal

interface/method

iii.客戶實(shí)現(xiàn)implementingtheclient

1.在遠(yuǎn)程接口定義后的任何時(shí)間都可以被實(shí)現(xiàn)canbeimplementedanytimewhen

theremoteinterfacehasbeendefined

第三章JMS

a）面對(duì)消息中間件MOM

i.在異構(gòu)平臺(tái)上發(fā)送/接收分布式應(yīng)用軟件/組件之間的消息

ii.Sending/receivingmessagesbetweendistributedapps/componentsover

theheterogeneousplatforms

1.支持異步調(diào)用

2.Supportingasynchronouscalls

iii.創(chuàng)建一個(gè)分布式通信層

iv.Createadistributecommunicationlayer

1.避開應(yīng)用開發(fā)者接觸來自不同系統(tǒng)和網(wǎng)絡(luò)接口的細(xì)節(jié)

2.InsulatingappdevelopersfromthedetailsaboutdifferentOSandnetwork

interfaces

v.在不同平臺(tái)和網(wǎng)絡(luò)上的API通常是MOM供應(yīng)的

vi.TheAPISfromdifferentplatformsandnetworkareprovidedbyMOM

b）比較

i.MOM

1.異步通信

2.Asynchronouscommunication

3.組件松散耦合

4.Loosely-coupledcomponents

ii.RPC/ORB

1.同步通信

2.Synchronouscommunication

3.組件緊密耦合

4.Tightly-coupledcomponents

c)MOM標(biāo)準(zhǔn)

i.歷史上，缺乏MOM的精確標(biāo)準(zhǔn)

ii.Therewasalackofstandardsinthehistory.

iii.高級(jí)消息隊(duì)列合同AMQP

iv.AdvancedMessageQueuingProtocol

v.數(shù)據(jù)分發(fā)服務(wù)DDS

vi.DataDistributionService

vii.可擴(kuò)展消息和存在合同XXMP

viii.extensibleMessagingandPresenceProtocol

ix.Java消息服務(wù)的JAVAEE

x.JavaMessageServicebyJAVAEE

1.由大多數(shù)MOM供應(yīng)商實(shí)施，旨在隱蔽特定的MOMAPI實(shí)現(xiàn)方法

2.ImplementedbymostMOMvendorsandaimstohidetheparticularMOM

APIimplementations

d)JavaMessageService

i.一種JAVAAPI接口，允許應(yīng)用程序創(chuàng)建發(fā)送接收讀取消息

ii.AjavaAPIthatallowsappstocreate,send,receiveandreadmessages

iii.定義一組通用接口和關(guān)聯(lián)用語

iv.Definesasetofcommoninterfaceandassociatedsemantics

v.通過JMS的供應(yīng)者，力爭最大力度的提高JMS應(yīng)用程序的可移植性

vi.TrythebesttoimprovetheportabilityofJMSappsacrossJMSproviders

Vii.使得通信變得松散耦合的，異步的，牢靠的

viii.Enablingcommunicationthatislooselycoupled,asynchronous,andreliable

e）當(dāng)用JMS的時(shí)候

i.供應(yīng)者盼望該組件不依靠與其他組件的接口信息，因此組件可以很簡潔地被替換

ii.Providershopethecomponentsdon'trelyonothercomponents,

message,socomponentscanbeeasilyreplaced

iii.供應(yīng)者盼望該應(yīng)用程序運(yùn)行時(shí)其他組件也同時(shí)運(yùn)行

iv.Providerswantstheappstorunwhetherornotallcomponentsareupand

runningsimultaneously

v.應(yīng)用業(yè)務(wù)模式允許組件將信息發(fā)送到另一個(gè)組件，并連續(xù)操作而不用即時(shí)響應(yīng)

vi.Applicationbusinessmodelallowscomponentssendmessagetoanother

componentsandtocontinuetooperatewithoutreceivinganimmediateresponse

f）信息傳遞方式

i.點(diǎn)對(duì)點(diǎn)傳送消息方式Pointtopointmessagingstyle

1.每個(gè)消息都是針對(duì)特定隊(duì)列的

2.Eachmessageisaddressedtoaspecificqueue

3.隊(duì)列將保留全部發(fā)送的消息，直到他們被消耗或者過期

4.Thequeuewillretainallthemessagesthathavebeensentuntiltheyare

consumedorexpire.

5.每一條消息都只有一個(gè)消費(fèi)者

6.Everymessagehasoneconsumer

ii.發(fā)布/訂閱消息方式Publish/subscribemessagingstyle

1.客戶端可以將信息發(fā)到一個(gè)主題里

2.Theclientcansendamessagetoatopic

3.出版社和訂閱者可以動(dòng)態(tài)的發(fā)布或者訂閱主題

4.Publisherandsubscribercandynamicallypublishorsubscribetothetopic.

5.當(dāng)且僅當(dāng)消息被發(fā)送給訂閱服務(wù)器后，主題才會(huì)保留信息

6.Topicwillretainthemessagesonlywhenmessageshavebeensenttothe

subscribers

7.每一條信息都可以有多個(gè)消費(fèi)者

8.Eachmessagehasmultipleconsumers

9.當(dāng)一個(gè)客戶端創(chuàng)建了一個(gè)主題后，另一個(gè)訂閱了相應(yīng)主題的客戶端才可以消費(fèi)已發(fā)

送的信息，并且消費(fèi)者必需要保持活躍來消費(fèi)信息

10.Afteraclientcreateatopic,anotherclientwhichhassubscribedthetopic

canconsumemessagesthathavebeensent,andtheconsumermustcontinueto

beactiveinorderforittoconsumemessages.

Queue

g）消息消費(fèi)

i.同步Synchronously

1.消費(fèi)者通過調(diào)用消息接收方法來獵取消息的目的地

2.Consumerfetchesthemessagefromthedestinationbycallingthereceive

method

3.假如消息沒有在指定時(shí)間內(nèi)到達(dá)，該接收方法會(huì)阻擋消息進(jìn)入

4.Thereceivemethodcanblockuntilamessagearrivesorcantimeoutifa

messagedosenotarrivewithinaspecifiedtimelimit

ii.異步Asynchronously

1.客戶端可以注冊(cè)一個(gè)消息監(jiān)聽器

2.Theclientcanregisteramessagelistenerwithaconsumer

3.當(dāng)消息到達(dá)目的地時(shí)，JMS的供應(yīng)者通過調(diào)用監(jiān)聽器的onMessage方法來供應(yīng)信

息

4.Whenmessagearrivestothedestination,theproviderofJMSdeliverthe

messagebycallingthelistener'sonMessagemethod

h)JMS元素

JMS供應(yīng)者：一個(gè)JMS接口的實(shí)現(xiàn)

ii.JMSprovider:animplementationoftheJMSinterface

iii.JMS客戶端：一個(gè)應(yīng)用或者過程，可以生產(chǎn)/接收消息

iv.JMSclient:anapplicationorprocessthatcanproduce/receivemessages

v.JMS供應(yīng)者/出版者:創(chuàng)建/發(fā)送消息的客戶端

vi.JMSprovider/publisher:aclientthatcancreate/sendmessages

vii.JMS消費(fèi)者：接收消息的客戶端

viii.JMSconsumer:aclientthatcanreceivemessages

ix.JMS消息：包含數(shù)據(jù)的對(duì)象，在客戶端之間轉(zhuǎn)移

x.JMSmessage:anobjectincludingdataandtransferredbetweenJMSclients

xi.JMS隊(duì)列：一個(gè)包含著已經(jīng)被發(fā)送出去并且等待被接收的信息（只有一個(gè)消費(fèi)者）中

轉(zhuǎn)區(qū)

xii.JMSqueue:aqueuethatincludemessageswhichhavebeensentand

waitingtoberead

xiii.JMS主題：一個(gè)發(fā)送信息給多個(gè)訂閱服務(wù)器的初版發(fā)行機(jī)構(gòu)

xiv.JMSTopic:adistributionmechanismforpublishingmessagesthatare

deliveredtomultiplesubscribers

i)JMS應(yīng)用程序的基本構(gòu)造塊JMSapplication,sbasicbuildingblocks

i.管理對(duì)象：連接工廠和目的地

ii.Administeredobjects:connectionfactoriesanddestinations

iii.鏈接

iv.Connections

v.會(huì)議

vi.Sessions

vii.消息生產(chǎn)者

viii.Messageprovider

ix.消息消費(fèi)者

x.Messageconsumer

Xi.消息

xii.Message

JMSAPIProgrammingModel

Creates

Message

Producer

CreatesReceives

Rom

DestinationDestination

j)JMS信息類型

JMSMessageTypes

MessageTypeBodyContents

TextMessageAjava.lang.Stringobject(fbrexample,thecontentsofanXML

file).

MapMessageAsetofname-valuepairs,withnamesasStringobjectsandvalues

asprimitivetypesintheJavaprogramminglanguage.Theentries

canbeaccessedsequentiallybyenumeratororrandomlybyname.

Theorderoftheentriesisundefined.

BytesMessageAstreamofuninterpretedbytes.Thismessagetypeisfbrliterally

encodingabodytomatchanexistingmessagefbnnat.

StreamMessageAstreamofprimitivevaluesintheJavaprogramminglanguage,

filledandreadsequentially.

ObjectMessageASerializableobjectintheJavaprogramminglanguage.

第四章JDBC

a)Intro

i.一套為了建立JAVA編程語言和更大范圍數(shù)據(jù)庫之間獨(dú)立性數(shù)據(jù)庫連接的標(biāo)準(zhǔn)JAVA

API接口

b)框架

JDBCArchitecture

?JDBCAPI&JDBCDriverAPI

C）組件

i.DriverManager

ii.Driver

iii.Connection

iv.Statement

v.ResultSet

vi.SQLexception

d)JDBC功能

i.制造一個(gè)數(shù)據(jù)庫連接

ii.產(chǎn)生SQL聲明

iii.在數(shù)據(jù)庫中執(zhí)行SQL語句

iv.查看修改產(chǎn)生的紀(jì)錄

e)生成一個(gè)簡潔的JDBC應(yīng)用

i.導(dǎo)入包

1.導(dǎo)入數(shù)據(jù)庫連接編程需要的JDBC類的包

2.Importjava.Sql

ii.注冊(cè)JDBCdriver

1.初始化一個(gè)driver,來建立一個(gè)與數(shù)據(jù)庫聯(lián)系的通信通道

2.Class.forName("com.mysqljdbc,driver");

iii.打開鏈接

1.制造一個(gè)鏈接對(duì)象，代表著與數(shù)據(jù)庫的物理連接

2.Staticfinalstringuser="username";

3.Staticfinalstringpass="password";

4.Conn=DriverManager.getConnection(DB_URL.user,pass);

iv.執(zhí)行語句

1.為了建筑并提交SQL說明給數(shù)據(jù)庫，使用聲明或者預(yù)備聲明

2.Stmt=conn.createStatement();

3.Stringsql;

4.Sql="SELECTid,name,hometownFROMt_student";

5.ResultsSetrs=stmt.executeQuery(sql);

6.對(duì)更新，插入，刪除進(jìn)行聲明

7.Stmt=conn.createStatementQ;

8.Stringsql;

9.Sql="DELETEFROMt.studentwhereid=l";

10.Intnum=stmt.executeUpdate(sql);

v.從結(jié)果中提取數(shù)據(jù)

1.用resultSet.getXXXQ從結(jié)果中提取數(shù)據(jù)

while(rs.next()){

//Retrievebycolumnname

intid=rs.getlnt("id");

Stringname=rs.getString(/znameH);

Stringhometown=rs.getString(//hometown")；

<)7

vi.清空環(huán)境

rs.close();

stmt.close();

conn.close();

\__________________________________)

f）數(shù)據(jù)類型

SQLJDBC/JavasetXXXupdateXXX

VARCHARjava.Iang.StringsetStringupdateString

CHARjava.Iang.StringsetstringupdateString

NUMERICjava.math.BigDecimalsetBigDecimalupdateBigDecimal

INTEGERintsetlntupdatelnt

FLOATfloatsetFloatupdateFloat

DOUBLEdoublesetDoubleupdateDouble

DATEjava.sql.DatesetDateupdateDate

TIMEjava.sql.TimesetTimeupdateTime

TIMESTAMPjava.sql.TimestampsetTimestampupdateTimestamp

g）執(zhí)行SQL語句

i.發(fā)送查詢語句給數(shù)據(jù)庫

ii.發(fā)送更新語句給數(shù)據(jù)庫

TheCallableStatementObject

CallableStatementcstmt=null;

try(

StringSQL="{callprocedureName(?,?)}'*;

cstmt=conn.prepareCall(SQL);

}

catch(SQLExceptione){

}

finally{

TheCallableStatementObject(cont.)

ParameterDescription

AparameterwhosevalueisunknownwhentheSQLstatementiscreated.

IN

YoubindvaluestoINparameterswiththesetXXX()methods.

AparameterwhosevalueissuppliedbytheSQLstatementitreturns.You

OUT

retrievevaluesfromtheOUTparameterswiththegetXXXf)methods.

Aparameterthatprovidesbothinputandoutputvalues.Youbindvariables

INOUT

withthesetXXXf)methodsandretrievevalueswiththegetXXXf)methods.

intstudentlD=102;

stmt.setlnt(l,studentID);

stmt.registerOutParameter(2,java.sql.Types.VARCHAR);

\________________________________________)

第五