《JAVA语言程序设计》期末考试试题及答案1-7

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JAVA
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75Â#ÑḄÂ஺(X)Z.ᓫ⚗⌱⚪1.JavaapplicatûnsḄg;◤ᒹümainJK(V¦ý⚗6mainJKḄþãEFÿ()AஹStringargsBஹStringar[]CஹCharargDஹStringBufferargsf]2.ᐵḄḄ()஺AஹᙠJavaᐕᓫBஹᙠJavaCஹᙠJava!"DஹᙠJavaᐕᓫ3.paint()#$%ᵨ'()Ḅ*ᦪ,()AஹGraphicsBஹGraphics2DCஹStringDஹColor4.'JavaḄ-.ᦪ/)()A>intBஹBooleanCஹfloatDஹchar5.'⚗1ᒹ34ᓫᩩ()oA>PanelFrameC>AppletDஹDialog6.6◤⌕9:;ᡈ#$=>%ᵨ'(?⛲A,()AஹstaticBஹpackageCஹprivateDஹpublic7.ᙠBCᘤ᡻FappletGH=⌱⚗Ḅ'#$JKᨬᐜ᡻F()oAஹinit()Bஹstart()CஹdestroyODஹstop()8.NO☢Qṹ=ᐵSGH'T$Ḅ,()publicclassPerson{staticintarr[]=newint[5];publicstaticvoidmain(Stringa[])(System.out.println(arr[0]);})AஹUV!JWX┯ZBஹUV!=[F!JWX┯ZCஹ\O]Dஹ\O^

89.ᑡ'`abᐵJavaᑁdeᦈḄTgḄ,()AஹGHᕒijklmGᩭopᑁdBஹᑁdeᦈGHqropsᵨᑁdCஹᑁdeᦈGHᐕGHᕒtopᑁdDஹᑁdeᦈGH1ᙠᢣ9Ḅ!vopᑁdwx10.'ᐵyz1ᵨᩭwwx{|}┝,()A^transientBஹsynchronizedCஹserializeDஹstatic11.Qṹ᡻FḄ\O()intx=-3inty=-10System.out.println(y%x);Aஹ-1Bஹ2Cஹ1Dஹ312.ᨵGHᱏ=ᑡ'⌱⚗ᐭᑮF1஺()1.2.publicclassInteresting{3.//dosth4.}Aஹimportjava.awt.*;Bஹpackagemypackage;CஹclassOtherClass{}DஹpublicclassMyClass{}13.ᨵ☢aba=Integer,parselnt("12");b=Integer.valueOf(u12,?).intValue();T$Ḅ()஺Aஹa᦮ᦪ)=b᦮ᦪwx஺Bஹa᦮ᦪwx=b᦮ᦪ)஺Cஹa"b᦮ᦪwx஺Dஹa"b᦮ᦪ)஺14.FilterOutputStreamBufferedOutputStreamஹDataOutputStreamPrintStreamḄ᱄='1FilterOutputStream᪀⌼ᦪḄ*ᦪ),AஹOutputstreamBஹFile

9CஹInputStreamDஹBufferedOutputStream15.ᙠUᑏJavaAppletGH!=◤ᙠGHḄᜮᑏ()ab஺Aஹimportjava.awt.*;B>importjava.applet.Applet;Cஹimportjava.io.*;Dஹimportjava.awt.Graphics;16.ParentஹChild9:᝞:1.publicclassParent2.{publicfloataFun(floata,floatb)throws3.lOException{}4.)5.publicclassChildextendsParent{6.7.}J'(#$ᐭF6ᔠ$Ḅ஺()AஹfloataFun(floata,floatb){}BஹpublicintaFun(inta,intb)throwsException(}CஹpublicfloataFun(floatp,floatq){}DஹpublicintaFun(inta,intb)throwslOException{}17.ᙠ%ᵨinterface£g!=1%ᵨ()?⛲A?⛲SI—IOAஹprivateBஹprotectedCஹprivateprotectedDஹpublic18ஹᨵ#$Ḅ9:=¤⌱¥S#$Ḅ¦e)()oReturnTypemethod(bytex,doubley)(return(short)x/y*2;)AஹbyteBஹshortC>intD>double19ஹᐵQṹḄT$Ḅ()1.Strings=Habcden;2.StringBuffersl=newStringBuffer("abcden);3.if(s.equals(sl))4.sl=null;5.if(sl.equals(s))

106.s=null;Aஹ§1FUV┯Z=StringḄ᪀⌼ᘤijg¨ᵨBஹ§3FUV┯Z=©sªsiᨵḄ)CஹUVᡂ¬=᡻F!ᙠ§5Fᨵ®¯°ODஹUVᡂ¬=±G²³ᨵ®¯°O20ஹUV[FGH=´'⌱⚗Ḅ()1.classX{2.protectiedStringtoString()i{3.returnsuper.toStringO;}4.)AஹUVµ±[Fs®¯BஹUVµ±[F!O┯CஹF2O┯=ᡂ¬UVDஹᡂ¬UV=F3O┯¶.GH▅¹⚪1.GHḄ\OOclassStringTestl(publicstaticvoidmain(String[]args)(Stringsi»"hello”Strings2=newString(nhello");if(sl.equals(s2)){System.out.println(“");}else{System,out.printin(")2.GHḄ\O56789publicclassTestArraypublicstaticvoidmain(Stringargs[]){

11inti,j;inta[]={5,9,6,8,7);for(i=0;i

12bw.close();¬ÀyÁ⌲\ᐭzA¿=⌲\OÃinput.txtᦻÅ=tÃ\ᐭ^F஺4.▅¹GH=ᑏO\O஺classAnimal{Animal(){System.out.print("Animal")}}publicclassDogextendsAnimal{Dog(){System.out.print("Dog”)}publicstaticvoidmain(String[]args){Dogsnoppy=newDog();}\OAnimalDogÆJAVAaÇGHÈÉÊËὃÍÍ⚪Îᫀ3Ð>ὃiᜓ⚪ÒÓஹᓫ⚗⌱¥⚪1ஹ᝞'JavaḄ᪗ÕAÐÓAஹpublicBஹsuperCஹ3numberDஹwidth2ஹ᝞'JavaḄ᪗ÕAÐÓAஹfieldnameBஹsuperCஹ3numberDஹ#number

133ஹÖ×᝞9:Strings=ustoryn;☢'abᔠ$ḄÐÓAஹs+="books11;Bஹs=s+100;Cஹintlen=s.length;DஹStringt=s+"abc”;4ஹ᝞'JavaᨵᦔḄᐵyz()AஹnameBஹhelloC>falseDஹgood5ஹ☢ḄQṹ᡻FÙcountḄÚÛ()intcount=1;for(inti=1;i<=5;i++){count+=i;)System.out.printin(count);Aஹ5Bஹ1Cஹ15Dஹ166ஹ9:=ij%ᵨḄᐵyz()AஹpublicBஹclassCஹinterfaceDஹstatic7ஹ9:ij%ᵨḄᐵyz()A>publicB>classC>interfaceD>static8ஹ᝞ÜᘤÝÅpḄÞßBorderLayout,ᑣᙠpḄáâ{ᢥäb,>S%ᵨḄab()Aஹp.add(b);Bஹp.add(b,'^North^^);Cஹp.add(b,,rSouthM);Dஹb.add(p'NorthH);9ஹ£gklᢥäwxb,>S%ᵨḄab()AஹButtonb=newButton();Bஹbuttonb=newbuttonQ;CஹButtonb=newb();Dஹb.setLabel("9”)10ஹFramewxæçḄÞßèᳮᘤ()AஹFIowLayoutBஹBorderLayoutCஹCardLayoutDஹnull11ஹᑡ'importêë1%ᡃíᙠGHkl\ᐭ/\Oïwx()

14Aஹimportjava.sql.*;Bஹimportjava.util.*;C^importjava.io.*;Dஹimportjava.net.*;12ஹ☢'importêë1ᡃíðñUᑏòó>ᵨGHḄ()Aஹimportjava.sql.*;Bஹimportjava.util.*;Cஹimportjava.io.*;D>importjava.net.*;13ஹ᝞◤⌕ÀᦻŹôᦪ/=ᑣ1ᙠGHkl'Ḅwx()AஹFilelnputStreamBஹFileOutputStreamCஹDataOutputStreamDஹFileWriter»ஹõ^⚪1ஹ᝞JMyClass£gpublic,öḄᦻÅ÷øij(MyClass.iava)ù¯UV஺2ஹJavaGHḄᓫFúoA(஻)=üFúoA(/**/)஺3ஹJavaÞþ)Ḅ¯ᨵ(=öí(true)"(false)04ஹJavaᵨ9:ÿᦪḄᐵᨵ(iloat)(double),ὅὅ஺5ஹJavaᵨᦪḄ(==),ᵨ!Ḅ(<>)o6ஹᙠJava#$%&'(Ḅ)*strḄ+,(Stringstr;),#$%ᐹᨵ10ᐗ/Ḅ᦮(ᦪ1aḄ+,(intnarr=newint[10];)஺7ஹ2ᐭmypackageᒹḄᡠ'Ḅ67(importmypackage.*;)஺8ஹ89:%ᦪ1intarr[]=newint[5];;<=>⊤=ᦪ1ᡠ@AḄ)*'((int),ᦪ1B(arr),ᦪ1ḄᜧDE(5),ᦪ1ᐗ/F᪗ḄHᵨJ(0ᑮ4)o9ஹᎷMx=13,y=4,ᑣ⊤OPx%y!=0ḄQ(true),ᐸᦪS'((boolean)஺

1510ஹUVᜐᳮᵫ(try)ஹ(catch)finallyᙽ[ᐵᡠ1ᡂḄ]^ᙽ஺11ஹ_F]^`Ḅabcd([ef)intx=5,y=6,z=4;if(x+y>z&&x+zுy&&z+y>x)System.out.printin("[ef”);elseSystem.out.printin("![ef");12ஹF☢]^`Ḅ᡻mcd(65432)inta[]={2,3,4,5,6);for(inti=a.length-1;i>=0;i--)System.out.print(a[i]+[ஹ]^▅o⚪1ஹ_F]^ḄabcdE%Peteris17yearsold!___஺publicclassPerson{Stringname;intage;publicPerson(Stringname,intage){this.name=name;this.age=age;}publicstaticvoidmain(String[]args){Personc=newPerson("Peter"<17);System.out.printIn(c.name+nis"+c.age+”yearsold!”)q}2ஹ_F]^ḄabcdE%:101:ASPᑖ:3—opublicclassCourse{privateStringeNumber;privateStringcName;privateintcUnit;publicCourse(Stringnumber,Stringname,intunit){eNumber=number;cName=name;cUnit=unit;

16}publicvoidprintcourseinfo(){System.outprintln("r]s:“+eNumber+'1r]B”+cName+”wᑖ”+cUnit);)}classCourseTest{publicstaticvoidmain(String[]args){Coursec;c=newCourse(n101n“ASP”<3);zc.printcourseinfo();)3ஹ_F]^ḄabcdE—z{|}~20.0—஺publicclassTom{privatefloatweight;privatestaticStringname;publicvoidsetweight(floatweight){this.weight=weight;)privatevoidout(){System.out.printin(name+“}~"+weight+“)publicstaticvoidmain(String[]args){Tom.na/ne="z{|”qTomcat=newTom();cat.setweight(20);cat.out();)4ஹ_F]^Ḅabcd_B:Tom:15ᙬ:ᵯ:66123456w᪥%஺publicclassFather{Stringname,address,tel;intage;

17publicFather(Stringname,intage){this.name=name;this.age=age;)voidout(){System.out.print("B"+name);System.out.print(n"+age);)voidoutOther(){System.out.print(nᙬ"+address);System.out.print(nᵯ"+tel);)}classSonextendsFather{Stringschool;publicSon(Stringname,intage){super(name,age);)voidout(){super.out();super.outOther();System.out.printIn(nw᪥”+school);}publicstaticvoidmain(Stringargs[]){Sonson=newSon("Tom”,15);son.address="”qson.school="”qson.tel="66123456”qson.out();))5ஹFᑡ]^Ḅmcd_12345—opublicclassMyClass{inta[]={1,2,3,4,5);voidout(){

18for(intj=0;jṹ᝞Ë⌨b<Í´᡻mfinallyᙽ஺2.ÎbUVJava+°µ_!ᙠÏÐÑÒᣓÀ<Óᵨthrow+,´UVÎÔÕÖḄ×ᵨὅ஺Throw+,¢ᩭ:ØᙢÎb%UVq✌ᐜÚÛ◤Ýᑮ%ThrowableḄ¯Þ,È<«¬ßᦪàᑮcatch<ᡈὅâᵨnewãäᩭåæ%஺2ஹçèéꫬÛ⌕Ḅì:¶í¯¡î'ï◤~ð#$¢ñᨵò%'ḄîóôឋÏÐ<¦ö=÷ᐵøùEéê<ᐜ#$Ḅ'ùE᱄'<#$Ḅ'ùEû'<¦üᐕþÿḄᐵ஺3ஹᑏḄḄᑏOverridingOverloadingJava᝱ឋḄ⊤஺ᑏOverriding᱄!"#᝱ឋḄ$%⊤&Overloading$'(᝱ឋḄ$%⊤஺᝞*ᙠ!(,-.ᐸ᱄ᨵ1Ḅ234ᦪ&ᡃ789:ᑏ(Overriding)஺!Ḅ<=>ᵨ@'A&BCᵨ!(Ḅ,-&

19Ḅ4ᦪN&ᑣ3PḄ(Overloading)஺OverloadedḄQRᦋTUVWḄN஺XஹYZ[\⚪1ஹᢥR_⌕abᑏYZ(1)cd$'Rectangle&efwidthheightg'ᡂᕒTj(2)ᙠRectangle(efg%ᑖ\lmnḄᕜp☢r(3)bYᑭᵨRectangletu$'mnḄᕜp☢rvpublicclassRectangle{floatwidth,height;publicRectangle(floatwidth,floatheight){this.width=width;this.height=height;)publicfloatgetLength(){return(this.width+this.height)*2;}publicfloatgetArea(){returnthis.width*this.height;)publicstaticvoidmain(String[]args){Rectanglerect=newRectangle(10,20);System,out.println(“ᕜp”+rect.getLength());System.outprintln("☢r“+rect.getArea());)2ஹᢥR_⌕abᑏYZ(1)bᑏAnimalyz&yz({|run()(2),-BirdFish}Animalyz(3)bᑏBirdFishḄ~YZ&Cᵨᐸ(Ḅrun()vpublicinterfaceAnimal{voidrun();classBirdimplementsAnimal{

20publicvoidrun(){System.out.printin("ᙠ...;)}classFishimplementsAnimal{publicvoidrun(){System.out.printin("ᙠ,”))}publicclassTestAnimal{publicstaticvoidmain(String[]args){Birdbird=newBird();bird.run();Fishfish=newFish();fish.run();}}3ஹbᑏ$'Frame᪾ᵨYZ&⌕a᝞_(1)ᙠz[g'ᓫ“ᦻ”ஹ“b”(2)ᙠ“ᦻ”ᓫef'ᓫ⚗“ᡭ”ஹ“”ஹ“ᐵ”(3)ᙠ“b”ᓫefg'ᓫ⚗“ᑴ”ஹ“”(4)¡¢ᐵᓫ⚗A&>YZᐵ஺vimportjava.awt.Color;importjava.awt.Frame;importjava.awt.Menu;importjava.awt.MenuBar;importjava.awt.Menuitem;importjava.awt.event.ActionEvent;importjava.awt.event.ActionListener;importjava.awt.event.WindowAdapter;importjava•awt.event.WindowEvent;/**¥¦*/publicclassMyFrameextendsFrame{

21privatestaticfinallongserialVersionUID=6895463895656626294L;privateFramefrmMain;//¦MenuBarmb;//ᓫ§MenumnuFile;//"ᦻ"ᓫMenumnuEdit;//"b”ᓫMenuitemmiOpen;//"ᡭ”ᓫ⚗MenuitemmiSave;//"”ᓫ⚗MenuitemmiClose;//"ᐵ”ᓫ⚗MenuitemmiCopy;//"ᑴ”ᓫ⚗MenuitemmiPaste;//"”ᓫ⚗publicMyFrame(){frmMain=newFrame("¥¦”)//cdᓫ§mb=newMenuBar();//cdᓫmnuFile=newMenu("ᦻ”)mnuEdit=newMenu("b“)//cdᓫ⚗miOpen=newMenu¨tem(“ᡭ”)miSave=newMenu¨tem(“”)miClose=newMenu¨tem("ᐵ“)miCopy=newMenu¨tem(“ᑴ”)miPaste=newMenu¨tem("“)}publicvoidshowFrame(){frmMain.setSize(800,600);frmMain.setLocation(100100);zfrmMain.setBackground(Color.white);frmMain.setVisible(true);frmMain.setLayout(null);frmMain.addWindowListener(newWindowHandler());//©ªz«¬ᘤ//Bᓫ§®ᐭ¦(frmMain.setMenuBar(mb);//Bᓫ®ᐭᓫ§(mb.add(mnuFile);

22mbadd(mnuEdit);//Bᓫ⚗®ᐭᓫ(mnuFile.add(miOpen);mnuFile.add(miSave);mnuFile.add(miClose);mnuEdit.add(miCopy);mnuEdit.add(miPaste);//©ª°±²«¬ᘤmiClose.setActionCommand(nmiClose_Clickedn);miClose.addActionListener(newMenuHandler());)//,-$'ᑁ´&ᙠ@'(bᑏzᐵ²ᜐᳮYZ஺privateclassWindowHandlerextendsWindowAdapter{publicvoidwindowclosing(WindowEvente){System,exit(0);//⌨uᵨYZ&¸᝱ṹ0⊤º»¼½¾&¿0⊤ºÀ¼½¾஺})//,-$'ᑁ´&ᙠ@'(bᑏ°±²ᜐᳮYZ஺privateclassMenuHandlerimplementsActionListener{publicvoidactionPerformed(ActionEvente){if(e.getActionCommand()==HmiClose_ClickedH){System,exit(0);//⌨uᵨYZ)}publicclassTestMyFrame{publicstaticvoidmain(String[]args){//Á°¥¦MyFrameguiWindow=newMyFrame();guiWindow.showFrame();)

23OAVAÂFYZ[\ÃÄÅὃ⚪Çᫀ4(ὃÉᜓ⚪Ë)—Vᓫ⌱⚪1ஹ_ᑡYZÍ᡻ÏÐḄÑ*()oStrings=newString(nabcdefg");for(inti=0;i

24A)aB)abcdeC)12345D)678906ஹ_☢ÂéḄêë()0RandomAccessFileraf2=newRandomAccessFile("1.txt","rw");A)ᡭìíîï_ḄᦻLtxt,ðQRᔣᦻᑏᦪò&óQRôᦻÛᦪò஺B)ᡭìíîï_Ḅᦻl.txt,õöëᔣᦻᑏᐭᦪò&ëôᦻÛÜᦪò஺C)ᡭìíîï_Ḅᦻl.txt,õëᔣᦻᑏᐭᦪò&öëôᦻÛÜᦪò஺D)R÷8ø<஺7ஹᵨYZḄmain(ᨵR_Âé&ᑣtuḄÑ*()஺Strings="12345#aaa#bbb#67890n;intn=s.indexOf("#")intk=s.indexOf(f,#n,n+l);intm=s.indexOf(n#n,k+l);Strings2=s.substring(m+1);System.out.println(s2);A)123456B)67890C)aaaD)bbb8ஹ_☢YZÍ᡻ÏÐbḄW()oIntegerinteg=newInteger(9)booleanb=integinstanceofObject;A)9B)trueC)1D)false9ஹᵨYZTestJavaḄùYZ᝞_&ᙠúûÏüᐭjavaTestaaabbcVýÐtuḄÑ*()0publicclassTest{publicstaticvoidmain(Stringargs[]){intkl=args.length;intk2=args[1].length();System.out.print(k1+""+k2);))A)32B)12C)13D)3310ஹᵨYZḄmain(ᨵR_Âé&ᑣtuḄÑ*()஺intb[][]={{l},{2,2},{2,2,2));intsum=0;for(inti=O;i

25for(intj=O;jmax)max=x[i];)System.out.println(max);A)125B)5C)98D)16812ஹTestjavaḄ()஺publicclassTest{Stringsl="javan;publicstaticvoidmain(Stringargs[]){intz=2;Testt=newTest();System,out.println(t.s1+z);))A)java2B)2C)ᨵD)java13ஹᵨḄmainᨵᑣḄ()஺Stringsl="0.5",s2="12";doublex=Double.parseDouble(s1);inty=lnteger.parselnt(s2);System.out.println(x+y);A)12.5B)120.5C)12D)“12.5”14ஹ☢Ḅ"#$%&ᦻ()*+ᵨᩭᔣᦻ(test.txtᦪ/Ꮇ1234567ᙠᦻ(test.txt,☢ḄTest.java9:3;ᑣᦻ(test.txtḄᑁ=()0

26importjava.io.*;publicclassTest{publicstaticvoidmain(Stringargs[]){try(Strings="ABCDE";byteb[]=s.getBytes();FileOutputStreamfile=newFileOutputStream("test.txt”,true);file.write(b);file.closeQ;)catch(IOExceptione){System.out.println(e.toStringO);A)ABCABCB)ABCDEC)TestD)ABCDEABCDEABCDE15ஹ☢?@6ABCollectionCDEḄ()?A)GHᐗJḄadd(Objectobj)B)ᑤ◀ᐗJḄremove(Objectobj)C)MᑮᐗJ&ᦪḄlength஺D)OPQRᘤḄiterator஺QRᘤᵨTᐗJUᔊ'⌱⚪1ஹ☢main஺ḄWXY@Z[Ḅ()?A)publicstaticvoidmain(Stringargsf]){}B)publicstaticvoidmain(String[]){}C)publicstaticvoidmain(String[]args){}D)publicstaticvoidmain(String[]x){}2ஹ\*+Ḅ]^ᕜ`abcᔊ☢Y@d᝱()oA)f#B)C)ghD)ij3ஹ☢kZ[Ḅ()oA)finallm⛲oஹpឋ(rs)ஹ஺B)abstractlm⛲oஹ஺C)t+uᨵᜮᨵw஺

27Dᐵyzfinal{abstract6|}~ᵨ஺4ஹ☢ᐵTjavaᐭ/)ḄkZ[Ḅ஺A
FilelnputStreamFileOutputStreamoᵨஹᑏz⁚)஺B
ReaderWriteroᵨᩭஹᑏz)஺0RandomAccessFilelᵨᩭᦻ(lᵨᩭᑏᦻ(஺D
Fileoᵨᩭᜐᳮᦻ(ᐵḄ஺5ஹ☢kZ[Ḅ□A᝞ᐳABDEᙠ%&ᦻ(ᑣABᦻ(ᐹᨵ}z஺B᝞ᦻ(ᒹimportᑣ:◀{᜜Ḅ¡%&஺C᝞ᦻ(ᒹpackageᑣ:¡%&¢ஹ¢஺DABḄWt+£l6ᵨᐵyzabstractm⛲஺6ஹ☢ᐵTJava¤bᜐᳮtryᙽḄkZ[Ḅ?Atryᙽabᨵ%&catchᙽᵨᩭᜐᳮtryᙽ¦Ḅ¤b஺B
catchᙽᨵfinallyᙽ஺Cl|¦¤bḄ§ᵨ¨ᙠtryᙽ஺D
*¦Ḅ¤bḄᜐᳮ¨ᙠtryᙽ7ஹ☢ᐵT©ஹ\ḄkZ[Ḅ
0A©Ḅ%;ª᝱᡻«஺%&©ᙠᐸ᡻«l]®&\——®\°ᡂ®ᩩ᡻\³஺B\´©µ¶Ḅ᡻ᓫ¸ᙠ%&©¹ºḄ»ᑴ)ᓽᑁ¾Ḅ»ᑴ)஺\¿À6|Áª᪠ÀT&©Ãᵫ©Ū᡻஺C
Java®\ḄÆÇᐵ஺D*TᓫᜐᳮᘤÈÉ®&\ᑖ~ËᱏÍÎCPUᡈᐸÐÈÉÑᩭ஺*T®ᜐᳮᘤÈÉ\lᑖÒᑮ®&ᜐᳮᘤÓÔÕZḄÖ×᡻®ØÙ஺8ஹᐵTBufferedReaderoḄreadLine஺kZ[Ḅ஺AreadLine
Ú;Î%ᦪ/஺B
readLine஺Ú;Î%&z⁚஺C:l|¦lOException¤b§ᵨ:~ab9Û¨ᑮtryᙽ

28Öa«catchᙽᜐᳮ¤b஺D)᝞ᑮ)ḄÜÝ:OPḄÞnull஺ஹ▅⚪1ஹ▅☢ḄPàá⚪(૘á3ᑖ૙á3ᑖᐳ6ᑖ)஺importjava.awt.*;importjavax.swing.*;publicclassTextendsJFrame{publicT(){super("GridLayoutn);Containercon=this.getContentPane();con.setLayout(newGridLayout(2,3))con.add(newJButton("an));con.add(newJButton("b"));con.add(newJButton("c,r));con.add(newJButtonC,d'*));con.add(newJButton(nen));con.add(newJButton(”f”))setSize(200,80);setVisible(true);)publicstaticvoidmain(Stringargs[]){newT();}}૘ãä⊤æḄä°ç☢஺૙᝞a«èé&ABᜐᳮᢥëḄªì(ᑣ:ABÞíîABḄᜮDE᝞íîàᫀð૙ABðActionListenerABḄðpublicvoidactionPerformed(ActionEvente)2ஹ▅☢ḄPàá⚪૘á3ᑖ૙á3ᑖᐳ6ᑖ஺஺

29importjava.util.*;publicclassT{publicstaticvoidmain(Stringargs[]){Setset=newTreeSet();set.add(newInteger(lO));set.add(newInteger(5));set.add(newInteger(15));set.add(newInteger(5));set.add(newInteger(lO));System.out.println(nsize="+set.size());Iteratorit=set.iterator();while(it.hasNext()){System.out.print(it.next()+n");૘Ḅ᝞íî૙kEjavaḄñᔠ(SetAB){᧜ô(MapAB)Ḅõ⌕÷ø஺àᫀð૘size=351015૙SetAB6ᒹùúᐗJḄñᔠMapAB9y᧜ôᑮûylùú£Ú&yᨬ®u|᧜ô%&û஺3ஹ▅☢ḄÖPàá⚪(૘á3ᑖ૙á3ᑖᐳ6ᑖ)஺importjava.io.*;publicclassTest{publicstaticvoidmain(Stringargs[])throwslOException{BufferedReaderbuf=newBufferedReader(newInputStreamReader(System.in));while(true){Stringstr=buf.readLine();if(str.equals("quitn))break;

30intx=lnteger.parselnt(str);System.out.println(x*x);)))ý☢Ḅð૘Óyþᐭ5,Pÿ
Ḅ᝞૙
ᐭquit,᡻᝞ᫀ૘25૙ᵨḄ஺JAVA!"#ὃ%%⚪(()ஹᓫ⌱⚪1ஹ+,-./ᜐ12Ḩ4᝱678-9.ᵨThread:;Ḅinterrupt஺<=;>?@6AḄBC:DE()஺A)lOExceptionB)RuntimeExceptionC)InterruptedExceptionD)ClassNotFoundException2ஹG☢ḄIḄJKE()oFilefile1=newFile(”d:\\xxx\\yyy\\zzz”)Mfilel.mkdirsO;A)ᙠ+OPQGRᡂTPQ\xxx\yyy\zzzB)RᡂPQe:\xxx\yyy\zzzC)ᙠ+OPQGRᡂᦻVxxx.yyy.zzzD)WXY=Z[\3ஹᵨḄmain<=;ᨵWG^_6ᑣ
ḄE()஺Strings=Hxxxxxxxxxxxxxxx#123#456#zzzzz";intn=s.indexOf("#");intk=s.indexOf("#n,n+1);

31Strings2=s.substring(n+l,k);System.out.println(s2);A)123456B)123C)xxxxxxxxxxxxxxxD)zzzzz4ஹᐵ1G☢ḄTest.javaY=/bḄE()஺publicclassTest{Stringx+T;inty;publicstaticvoidmain(Stringargs[]){intz=2;System.out.println(x+y+z);})A)3B)102C)12D)ᨵcd┯f5ஹᵨḄmain<=;ᨵWG^_6ᑣ
ḄE()஺intb[][]={{l,1,1},{2,2},{3});intsum=0;for(inti=0;i

32A)125B)5C)98D)1687ஹᵨḄmain<=;ᨵWG^_6ᑣ
ḄE()஺HashtablehashtablegnewHashtable();hashtable.put(nlOO^/'ana");hashtable.put(“200",“bbb")Mhashtable.put(',3OO,,M,cccn);System.out.println(hashtable.get(,,300,,).toString()+hashtable.get(n200n).toString()+hashtable.get(,,100',).toString());A)aaaB)bbbC)cccD)cccbbbaaa8ஹWGᐵ1javaBCY=[/bḄE()oA)Throwable:EJava^h;Error:iException:Ḅ᱄:஺B)+BC\kEException:(ᡈᐸT:)Ḅno@6KpqJavarstᡈὅthrow^_AvBC\k6wKpqtry…catch...finallyᜐᳮ஺C)᝞yᵨ-9catchᙽᣓᣍ}9BC\k6ᑣcatchT_;Ḅ~ᦪ:DEᡠᨵBC\kḄ᱄:஺D)WXY=Z[\஺9ஹG☢Ḅ-9ᦻV
\k6ᵨᩭᔣᦻVtest.txt;
ᦪ6Ꮇ+OPQG[ᙠᦻVtest.txt,cdG☢ḄTest.java6v36ᑣᦻVtest.txtḄᑁE()oimportjava.io.*;publicclassTest{publicstaticvoidmain(Stringargs[]){try(Strings="ABCDE”Mbyteb[]=s.getBytes();FileOutputStreamfile=newFileOutputStreamC^test.txt'*,true);file.write(b);file.closeQ;catch(IOExceptione){

33System.out.println(e.toStringO);A)ABCABCB)ABCDEC)TestD)ABCDEABCDEABCDE10ஹG☢Y=[/bḄE()?A⊤(List)ஹᔠ(Set)i᧜(Map)ZEjava.utilᒹ;Ḅ஺B)ListEWᒹᐗḄᨵᔠ஺C)SetE[ᒹᐗḄᔠ஺D)Map᧜ᑮ6W6¡9ᨬ}yK᧜-9஺ஹ⌱⚪1ஹG☢£¤ᐵ¥Kᵨᩭ¦ᑴ\:ᡂᕒḄ©ª()?A)publicB)protectedC)privateD)default2ஹG☢ᐵ1Java;BCᜐᳮtryᙽḄY=/bḄE()?A)tryᙽpCᨵ-9catchᙽ6ᵨᩭᜐᳮtryᙽ;AḄBC஺B)catchᙽ«¬ᨵfinallyᙽ஺C)KABCḄ<=ᵨ®ᙠtryᙽ;஺D)\AḄBCḄᜐᳮ«¬®ᙠtryᙽ;3ஹ.\kḄR¯ᕜ";6pC±ᔊG☢£¤4᝱()-A)´B)C)µ¶D)·¸4ஹ¹º᝞GḄg»ᦪ¼b,G☢ḄY=/bḄE()஺intb[][]={{l,2,3},{4,5},{6,7,8}}};A)b.lengthḄE3஺B)b[l].lengthḄE3஺ḄE5஺D)g»ᦪ¼bḄ½-ᨵ39ᐗ5ஹ:BE-9¾k:6:CE:BḄ¿¾kT:6Gᑡ\kxlḄ^_;/bḄE()஺A)Bxl=newB();B)Bxl=newC();C)Cxl=newC();D)Cxl=newB();

346ஹG☢ᐵ1Áஹ.ḄY=/bḄEÂÃ஺AÁEḄ-Ä᝱᡻q஺-9Áᙠᐸ᡻q;6WÅR}9.——}.6Çᡂ}ᩩ᡻.É஺B.EÊÁËÌḄ᡻ᓫÎ6Eᙠ-9Á;ÏÐḄ¦ᑴ6ᓽᑁÒḄ¦ᑴ஺.ÓÔ[KÕÄ6᪠Ô1,9Á×;6ᵫÁÙÄ᡻஺C
Java}.ḄÚÛÜÝᐵ஺D\1ᓫᜐᳮᘤßà6}9.ᑖ@âᱏäåCPUᡈᐸæßàçèᩭ஺\1}ᜐᳮᘤßà6.Wᑖéᑮ}9ᜐᳮᘤ;67ê/Ḅwë᡻}ìí஺7ஹG☢ᐵ1᜜Ò:iᑁÒ:ᡂᕒḄÝ頻Ḅðᑣ;6/bḄ⌱⚗EÂÃ஺AᑁÒ:Wó©ª᜜Ò:ḄᡂᕒB
᜜Ò:Wó©ªᑁÒ:ḄᡂᕒC
᜜Ò:[K©ªᑁÒ:ḄᡂᕒD᜜Ò:pqᑁÒ:Ḅnoᩭ©ªᑁÒ:Ḅᡂᕒஹ▅⚪1ஹ▅õG☢Ḅöṹ6wª⚪Â૘ª3ᑖ6૙ª3ᑖ6ᐳ6ᑖÃ஺Stringsi=newString^'abcde'^
;Strings2=newString”abcde"
;booleanbl=sl.equalss2
;booleanb2=sl==s2;System.out.printb1+""+b2
;૘I᡻6ᙠ¯ùḄ
᝞૙úû
1
ḄḄüýᫀ૘truefalse૙equals<=Êþÿ
Ḅᑁᔲ“==”ᑨᔲᢣᔣᵨᓽᔲ஺2ஹ▅!"☢Ḅ$%&'()⚪+૘)3ᑖ૙)3ᑖᐳ6ᑖ.஺importjava.io.*;publicclassTest{publicstaticvoidmainStringargs[]
throwslOException{BufferedReaderbuf=newBufferedReader(

35newInputStreamReader(System.in));while(true){Stringstr=buf.readLine();if(str.equals(',quit,'))break;intx=lnteger.parselnt(str);System.out.println(x*x);0123☢Ḅ$%4૘5678ᐭ10,':;8<Ḅ=>᝞@A૙5678ᐭexit,':;$%BCD᡻2ᔩAGHAᫀ૘100૙IBJKLInteger.parselnt(str)IBM
“exit”Nᓄ᦮ᦪR(6ᑖ)஺publicclassTest{publicstaticvoidmain(Stringargs[]){newStudent("Tom",'m',90,88);newStudent(nJackH,*m',66,89);newStudent("Mary",'f,76,86);System.out.println(nname\tsex\tchinese\tenglishu);Student.print();classStudent{protectedStringname;protectedcharsex;protectedintChinese;protectedintenglish;protectedStudentnext;staticStudentlist;

36Student(Stringname,charsex,intChinese,intenglish)this.name=name;this.sex=sex;this.chinese=chinese;this.english=english;this.next=list;list=this;)staticvoidprint(){Studentfriend=list;if(friend==null)System.out.println(nThelistisempty.");else{do{System.out.println(friend.toStringO);friend=friend.next;}while(friend!=null);))publicStringtoStringO{returnnewString(name+n\t',4-sex+u\t"+chinese+,'\t,,+english);ᫀnamesexChineseenglishMaryf7686Jackm6689Tomm9088

37XJAVA$%YZ[\]ὃ__⚪+`.ஹab⚪1.cdeḄfᶇ
+class.,cdijḄfᶇ
+interface.஺2.SocketkTlm+ᝅi
.,ᵨopq+IPᙢᙬ.t+uj.஺3.v$Ḅwᐜyᙠ+1.{+10.|}ᦪ~ᜧ+ញ.஺4.᪀⌼KLᱯḄᡂᕒKL᪀⌼KL+e.஺5.JavaᐕᓫᢣeBᨵ+᱄e.஺6.Java$%Ḅ᡽!.java,01;Ḅ$%Ḅ᡽+.class.஺7.ᙠ}Bᵫv$)Ḅ¡m+¢£¡.஺)¢£¡Ḅ¤ṹ+¢£¤ṹ.஺8.ᙠ¦v$§¨©¦v$|}ᨵ+ª.t+«¬.ᐵ§஺®ஹ⌱°⚪1.ᐵo⌱°=᪀"ᑡ²³LCDA+.A.if´telse´µ¶ᡂ<·B.if´¸¹ºᨵelse´»C.switch=᪀©case´©µ¶ᵨbreak´D.switch=᪀©µ¶ᨵdefault´2.while¼½tdo…while¼½Ḅ¾¿4+.A.ºᨵ¾¿À=᪀@ÁÂ"ᦔ>᪵B.while¼½Ådo…while¼½᡻2ᦔ᳛ÇC.while¼½ᐜ¼½;ᑨᡠ¹¼½É{ÊË᡻2ÌD.do…while¼½ᐜ¼½;ᑨᡠ¹¼½É{ÊË᡻2Ì3.ᐵofor¼½twhile¼½Ḅ³L²CDA+.A.while¼½ᐜᑨ;᡻2for¼½ᐜ᡻2;ᑨ஺B.while¼½ᑨᩩÎÏ$%=>for¼½ḄᑨᩩÎÏÐ$%=>C.¼½@᎛ÒI¸¹ÓᣚD.¼½=᪀©Òµ¶ᨵ¼½É¼½ÉIBb4."ᑡÕ⛲©)×ᑴÙᐵḄ+.

38A.privateB.publicC.protectedD.final5.voidḄÚd4+.A.KLºᨵÛ'~B.KLÉbC.ºᨵÜdD.cdKLµ¶Þᵨ6.return´4+.A.BÝKLÛ'ᦪ~B.KLÒµ¶ÚᨵC.KL©¸¹ᨵ¦´returnD.IBᵨᩭÛ'7.ᐵoᡂᕒᓰᵨᑁáḄ³L²CDA+.A.eḄᐳᵨâᑁáBஹeḄÞᵨIḄᑁáâã☟᝱ᡂᕒᐳæḄᑁáb}C.ḄKLIᓰᵨᑁáD.¹3ÒI8."ᑡ³L²CDAA.I◤⌕cdeéBêëB.©µ¶ᨵìឋtKLC.ìឋ¸¹îᓫïðl¸¹Dஹìឋµ¶îᓫïð9."ᑡ³L²CDA+.Aஹ$%¸¹ᒹÚ¦ᦻÎBஹᦻΩBᨵeCஹᦻΩ¸¹ᨵ¦óᐳeDஹᦻÎBô$%Þᵨ10.ᐵoKLmain+.Ḅ³L²CDA+.A.KLmain+.Bõᙠóᐳe©Bmain஺Ḅᜮcd¸¹᪷øÁÂÜùᦋC.1e©¸¹ºᨵmain஺KLD.ᡠᨵḄêëÒµ¶õᙠmain஺KL©

3911.᪀⌼ûᦪ@ËüᵨAAஹêëBஹecdCஹÞᵨḄKLDஹÞᵨḄìឋ12.ýKL4+.Aஹ¸¹ᨵKLÉBஹ¸¹<·ᙠÐýe©CஹºᨵKLÉḄKLDஹýe©ḄKLÒýKL13.ᐵoḄ³LCDḄ4+.AஹþeM᱄eᡠᨵḄìឋtKL஺BஹþeM᱄eḄÐÿᨵ
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4

4017.⌚B(CDḄᐵE5Aஹ⌚BᨵFGᙠ᱄(HICD#$FGᙠ&!4B.⌚B#$&'CD)*&'C.finalJ⛲Ḅ#$L⌚BM"LCDD.⌚B(CD5&!NO18.ᐵPQAஹRS!PQ)*RSPQḄᡠᨵB.!"RS!PQC.PQI"ᨵᐵED.PQU@5&!NO19.VWᒹYZᑡ\ᑁ]A.^_᡻ab^4⍗ᑮḄOᐜfᨵ⚜ᧇᑮḄijB.^_4Ḅk┯mC.^_Ḅno┯mD.$p2520.?qrL-.b#"stVWḄkuᙠn^v1Aஹ)*/ᵨtry/catchkuᜐᳮVWᡈᵨthrowszᐸstB.᝞}^_┯m)*/ᵨtry/catchkuᜐᳮVWC.#$~HᳮD."/ᵨtry/catchkuᜐᳮ21.(⁚ḄᙠA.>ὅᨵὅfᨵB.>ὅ5ᙽᑏὅ5⁚ᑏC.ὅfᨵ#$ᣚ/ᵨD.ᑏḄ⁚ᦪ&22.Zᑡ4
⁚)A.FilelnputStreamB.BufferedlnputStream

41C.FilterlnputStreamD.InputStreamReaderஹ^_⚪1.publicclassSum{publicstaticvoidmain(String[]args){intj=10;System.out.println("jis:"+j);calculate^);System.out.println(nAtlast,jis:"+j);)staticvoidcalculate(intj){for(inti=0;i<10;i++)j++;System.out.printlnCJincalculate()is:"+j);))t}1jis1(1)jincalculate()is:(2)Atlastjis:(3)ᫀ1(1)10%(2)20%(3)10»2.ᢥ⌕abstractclassSuperAbstract{voida(){...}abstractvoidb();abstractintc(inti);)interfaceAsSuper(voidx();abstractclassSubAbstractextendsSuperAbstractimplementsAsSuper

42publicvoidb(){...}abstractStringf();publicclassInheritAbstractextendsSubAbstract{publicvoidx(){...}publicintc(inti)publicStringpublicstaticvoidmain(Stringargs[]){InheritAbstractinstance=newInheritAbstract();instance.x();instance.aQ;instance.b();instance.c(lOO);System.out.println(instance.f());ᙠ$p^_41U@ᨵ1SuperAbstract(1)(ᑏt')U@ᨵ:(2)(ᑏt')PQᨵ1(3)(ᑏtPQ')AsSuper4Ḅx()5(4),ᡠ$ᙠInheritAbstract4)*?¥¦a(5)&ᫀ((1)SuperAbstract%(2)InheritAbstract%বAsSuper%(4)*+%(5)⌚-./0஺3.ᢥ§¨©ᡂ^_publicclassLeaf{privateinti=0;//«
ឋ¬ᵨ®Leafincrement(){஻-.increment(),°N¬5LeafḄ?@i++±return(1)"/z=>?@Ḅᙢᙬ´°N¬°N

43voidprint(){System.out.println("i="+i);)publicstaticvoidmain(Stringargs[]){Leafx=(2);஻µ¶LeafḄ?@xx.increment().increment().increment().print();}஻%¸ᵨincrement஺°NḄ25xḄᙢᙬi¬⊤º¸ᵨᦪ)t}i=(3)ᫀ1(1)this%ফnewLeaf()%ব34.ᢥ§¨»º©ᡂᦻ½¾ᑴḄ^_//FileStreamÀÁṹ᝞Z1importjava.io.*;classFileStream{publicstaticvoidmain(Stringargs[]){try(FileinFile=newFile(nfilel.txtn);//ᢣ-Àᦻ½FileoutFile=newFile("flle2.txt”);//ᢣ-Ã᪗ᦻ½FilelnputStreamfis=(1);FileOutputStreamfbs=newFileOutputStream(outFile);intc;//⌲⁚ÆÀᦻ½4ᐭÈtᑮfoswhile((c=fis.read())!—1)(2)±fis.close();fos.close();)catch(Exceptione){System.out.println(nFileStreamsTest:"+e);

44}ᫀপnewFilelnputStream(inFile);ফfos.write(c);5.▅^_Êt}1//AbstractClassDemo.javaÀÁṹ᝞Z1abstractclassShape{஻-.U@ShapeU@displayabstractvoiddisplayO;}classCircleextendsShape{voiddisplayO{஻RSU@ḄSystem.out.println("Circlen);)}classRectangleextendsShape{voiddisplayO{//RSU@ḄSystem.out.println(,,Rectanglen);))classTriangleextendsShape{voiddisplayO{//RSU@ḄSystem.out.println(nTrianglen);))publicclassAbstractClassDemo{publicstaticvoidmain(Stringargs[]){(newCircle()).display();஻-.Ë'?@ᩭ¸ᵨ?ÍḄdisplay(newRectangle()).displayO;(newTriangle()).displayO;

45t}5ᫀ1পCircle%(2)Rectangle%(3)TriangleoÎJAVA^_ÏÐÑÒÓὃÕÕ⚪(Ö)!ஹ⌱Ø⚪1.ÙtZᑡÁṹḄ᡻a}1Strings=“abed”±Stringsi=newString(s);if(s==si)System.out.println(nthesame")±if(s.equals(sl))System.out.println(nequals");A.thesameequalsB.equalsC.thesameD.ÚÛ}2t2.ZᑡᨵᐵJava4PQḄ5ḄA.PQ4YᨵᐹÝḄRSÁṹB.Þ!⌕RS!PQᑣᵨᑮ“implements”ᐵàC.Þ!⌕RS!PQᑣᵨᑮ“extends”ᐵàD.PQᐕâ3.ZᑡÁṹḄ᡻a}5ÚÛStringsi="aaa”±sl.concat(nbbb");System.out.println(s1);A.Thestring"aaan.B.Thestring,,aaabbbn.C.Thestringnbbbaaan.D.Thestring"bbbn.4.᝞}ᨵ!?@myListener(ᐸ4myListener?@RSãActionListenerPQ)Zᑡᩩku/åmyListener?@"æPçᜐᳮᩭ+smallButtonᢥè?@Ḅé´O½A.smallButton.add(myListener);B.smallButton.addListener(myListener);C.smallButton.addActionListener(myListener);D.smallButton.addltem(myListener);

46^_⚪1.ZᑡÁṹt^_Ḅê"஺importjava.io.*;publicclassTest{publicstaticvoidmain(String[]argv){BufferedReaderis=newBufferedReader(newInputStreamReader(System.in));StringinputLine;While((inputLine=is.readLine())!=null){System.out.println(inputLine);)is.close();}catch(lOExceptione){System.out.println(nIOException:"+e);ᫀ1ëàìᐭíºᑮîïpðᑮàìᐭñ஺2ஹZᑡ^_ᑏtḄòa}஺classtest{publicstaticvoidmain(String[]args){intx=9,y;if(x>=0)if(x>0)y=i;elsey=0;elsey=-l;System.out.println(y);ᫀ11

473ஹ^_ᑏtḄòa}஺publicclassFather(inta=100;publicvoidminer(){a-±}publicstaticvoidmain(String[]args){Fatherx=newFather();Sony=newSon();System.out.println(y.a);System.out.println(y.getA());y.miner();System.out.println(y.a);System.out.println(y.getA());)}classSonextendsFather{inta=0;publicvoidplus(){a++;)publicintgetA(){returnsuper.a;)}ᫀ10100099.ô⚪1.JavakõḄᱯ÷஺

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zC1ஹ|}0ᩭOPRunnableSTclassTestThreadimplementsRunnable{publicvoidrun(){…}2ஹ~Thread0ᩭOP

49classTestThreadextendsThread{TestThread(Stringname){super(name);start();)publicvoidrun(){…}