通過實(shí)例把握RMI，RPC，JDBC等中間件的使用。RPC實(shí)現(xiàn)遠(yuǎn)程計(jì)算效勞。效勞器端供給計(jì)算效勞；客戶端調(diào)用計(jì)算效勞。RMI+JDBC遠(yuǎn)端數(shù)據(jù)庫的訪問。實(shí)現(xiàn)簡潔的成績查詢系統(tǒng)〔創(chuàng)立表，錄入成績，查詢成績等。在效勞器端，通過JDBC訪問數(shù)據(jù)庫?？蛻舳苏{(diào)用效勞端供給的各種數(shù)據(jù)庫操作。效勞器和客戶端不在同的機(jī)器上進(jìn)展測(cè)試。打包成易于執(zhí)行的文件，如exe,bat文件。1利用RPC實(shí)現(xiàn)遠(yuǎn)程計(jì)算效勞。使用IDL定義效勞接口mathservice.idl,定義計(jì)算效勞操作，方法如下：加：voidCal_Add([in]doublea,[in]doubleb,[out]double*result);減：voidCal_Sub([in]doublea,[in]doubleb,[out]double*result);乘：voidCal_Mul([in]doublea,[in]doubleb,[out]double*result);除：voidCal_Div([in]doublea,[in]doubleb,[out]double*result);編寫配置文件mathservice.acf,定義綁定句柄編譯mathservice.idl文件,產(chǎn)生文件mathservice.h,mathservice_s.c,mathservice_c.c編寫效勞端程序,編譯連接工程，生成mathservice.exe編寫客戶端程序測(cè)試：測(cè)試結(jié)果截圖如下：加法運(yùn)算：減法運(yùn)算：乘法運(yùn)算：除法運(yùn)算：2RMI+JDBC遠(yuǎn)端數(shù)據(jù)庫的訪問(1)mysql-connector-java-5[1].0.8.zipDBmanagermysql數(shù)據(jù)庫，實(shí)現(xiàn)創(chuàng)立表，錄入成績，查詢成績等操作，主要代碼如下：//加載驅(qū)動(dòng)，獵取連接static{try{Class.forName(“com.mysql.jdbc.Driver“);cn=DriverManager.getConnection(url,username,password);}catch(Exceptione){e.printStackTrace;}}//創(chuàng)立表publicbooleancreateTable{inti=0;try{ps=cn.prepareStatement(““+“createtablermitest(idintprimarykey,namevarchar(20)notnull);“);i=ps.executeUpdate;}catch(SQLExceptione){//TODOAuto-generatedcatchblocke.printStackTrace;}if(i!=0){returntrue;}else{returnfalse;}}//插入數(shù)據(jù)publicbooleaninsertDate{intj=0;try{ps=cn.prepareStatement(“insertintormitestvalues(100,”rmitest”)“);j+=ps.executeUpdate;}catch(SQLExceptione){//TODOAuto-generatedcatchblocke.printStackTrace;}if(j!=0)returntrue;elsereturnfalse;}//獵取數(shù)據(jù)publicStringgetDate{ResultSetrs=null;Stringresult=““;try{ps=cn.prepareStatement(“select*fromrmitest“);rs=ps.executeQuery;while(rs.next){result+=“id=“+rs.getObject(1).toString+“,name=“+rs.getObject(2).toString+“\n“;}}catch(SQLExceptione){//TODOAuto-generatedcatchblocke.printStackTrace;}returnresult;}}定義效勞接口DataServic如下：publicbooleancreateTablethrowsRemoteException;publicbooleaninsertDatethrowsRemoteException;publicStringgetDatethrowsRemoteException;實(shí)現(xiàn)效勞，對(duì)實(shí)現(xiàn)創(chuàng)立表，錄入成績，查詢成績等操作。實(shí)現(xiàn)過程中可直接使DBmanager類，主要代碼如下：publicclassDataServiceImplextendsUnicastRemoteObjectimplementsDataService{DBmanagerdBmanager;publicDataServiceImplthrowsRemoteException{super;dBmanager=newDBmanager;}//調(diào)用DBmanager的方法創(chuàng)立表publicbooleancreateTable{returndBmanager.createTable;}//調(diào)用DBmanager的插入數(shù)據(jù)publicbooleaninsertDate{returndBmanager.insertDate;}//調(diào)用DBmanager的方法顯示數(shù)據(jù)publicStringgetDate{returndBmanager.getDate;}DeployServer，主要代碼如下：//創(chuàng)立遠(yuǎn)程對(duì)象DataServiceImplds=newDataServiceImpl;LocateRegistry.createRegistry(1117); //配置端口//遠(yuǎn)程對(duì)象綁定到效勞Naming.rebind(“//localhost:1117/ds“,ds);System.out.println(“RMI效勞器正在運(yùn)行。。。。。?！?;使用DataService接口，實(shí)現(xiàn)客戶端RmiJDBCClient類，主要代碼如下：DataServiceds=(DataService)Naming.lookup(“//localhost:1118/ds“);System.out.println(“獵取遠(yuǎn)程數(shù)據(jù)庫中數(shù)據(jù)如下:“);ds.createTable;//調(diào)用遠(yuǎn)程創(chuàng)立表方法ds.insertDate;//調(diào)用遠(yuǎn)程插入數(shù)據(jù)方法System.out.printl