Java常见面试题集--面试题全面综合(一)

11.2.3.4.2String?byteintcharlongfloatdoublebooleanshortjava.lang.StringfinalStringBuffer3int IntegerJavaIntjavaIntegerjavaintJavabooleanBooleancharCharacterbyteByteshortShortintIntegerlongLongfloatFloatdoubleDouble nullClick to buy NOW!PDF­XCHANGE­track.comClick to buy NOW!PDF­XCHANGE­track.com4StringStringBufferJAVAStringStringBufferStringStringBufferStringBufferStringBuffers5java6ServletServletCGIServletinitserviceservicedoXXXdoGetdoPostdestroycgiservletserviceCGIservlet7ArrayList,Vector, LinkedListArrayListVectorVectorsynchronizedArrayListLinkedList8EJBSessionBeanEntityBeanStatefulBeanStatelessBean    EJBSession BeanEntity BeanMessage Driven BeanJNDIRMIJATSessionBeanJ2EEEJBEntityBeanSessionBeanEntityBeanSession Bean Stateful Session Bean Stateless Session Bean Session Bean method Stateful Session Bean Stateful Session BeanStateless Session Bean Stateless Session BeanEJBContainer Stateless Session Bean method Stateless Session Bean methods Bean Instance Stateful Session Bean Stateless Session Bean Stateful Session Bean J2EEServer Stateful Session BeanClick to buy NOW!PDF­XCHANGE­track.comClick to buy NOW!PDF­XCHANGE­track.com9Collection CollectionsCollectionSetList.Collections10&&&    &&&and11HashMapHashtable    HashMapHashtableMapHashMapnullkey,HashtableHashMapnullentrykeyvalueHashtableHashMapHashtablecontainscontainsvaluecontainsKeycontainsHashtableDictionaryHashMapJava1.2Map interfaceHashtableSynchronizeHashMapHashtableHashMapHashtableHashMaphash/rehash12final, finally, finalizefinalfinallyfinalizeObject13sleep() wait()?    sleepThreadsleepwaitObjectwaitnotifynotifyAll14OverloadOverrideOverloaded?OverridingOverloadingJavaOverridingOverloading (Overriding)(Overloading)Overloaded15errorexception?errorClick to buy NOW!PDF­XCHANGE­track.comClick to buy NOW!PDF­XCHANGE­track.com    exception1617abstract classinterface?abstract classabstractAbstractinterfacestatic finalinstanceof18heapstack19forwardredirectforwardURLURL    redirect,,session,request20EJBJAVA BEANJava BeanJava BeanJavaBeanJava BeanTomcatJava BeanJava BeanSerializableBeanJava BeanCOMCOMEnterprise Java BeanDCOMJavaRMIEJBEJBWebspereWebLogicEJBEJBEJBEJBEJBEJB21Static Nested Class Inner ClassClick to buy NOW!PDF­XCHANGE­track.comClick to buy NOW!PDF­XCHANGE­track.com    Static Nested Classstatic22JSPINCLUDEINCLUDEINCLUDEjsp:includeINCLUDEinclude,23assert    assertion()assertionbooleanbooleantruefalseassertionassertionassertion24GC?GC?GCGabage Collection,JavaGCJava25short s1 = 1; s1 = s1 + 1;? short s1 = 1; s1 += 1;?    short s1 = 1; s1 = s1 + 1;s1+1intshort s1 = 1; s1 += 1;26Math.round(11.5)? Math.round(­11.5)?    Math.round(11.5)==12Math.round(­11.5)==­11round1/2floor.27String s = new String(xyz);String Object?284j1j1jpublic class ThreadTest1{  private int j;  public static void main(String args[]){ThreadTest1 tt=new ThreadTest1();Inc inc=tt.new Inc();Dec dec=tt.new Dec();for(int i=0;i2;i++){Thread t=new Thread(inc);Click to buy NOW!PDF­XCHANGE­track.comClick to buy NOW!PDF­XCHANGE­track.comt.start();t=new Thread(dec);t.start();}}  private synchronized void inc(){j++;System.out.println(Thread.currentThread().getName()+­inc:+j);  }  private synchronized void dec(){j­­;System.out.println(Thread.currentThread().getName()+­dec:+j);  }  class Inc implements Runnable{public void run(){for(int i=0;i100;i++){inc();}}  }  class Dec implements Runnable{public void run(){for(int i=0;i100;i++){dec();}}  }}29Javagoto?javajava30run()start()?start()JVMrun()Click to buy NOW!PDF­XCHANGE­track.comClick to buy NOW!PDF­XCHANGE­track.com31EJBSessionBean,EntityBeanSessionBeanStateless Session BeanBeanEJBBeanStateful Session BeanBeanStateful Session BeanBeanEntityBeanEntity BeansEntitybeansEJBEntity beansEntity Beans BeansEJBOMGOTSSun MicrosystemsTransaction ServiceJTSJava Transaction APIJTAX/OpenXA32BEA WebLogic ServerIBM WebSphere Application ServerOracle9i Application ServerjBossTomcat33runtime exceptionArithmeticException, ArrayStoreException, BufferOverflowException, BufferUnderflowException,CannotRedoException, CannotUndoException, ClassCastException, CMMException,ConcurrentModificationException, DOMException, EmptyStackException, IllegalArgumentException,IllegalMonitorStateException, IllegalPathStateException, IllegalStateException, ImagingOpException,IndexOutOfBoundsException, MissingResourceException, NegativeArraySizeException,NoSuchElementException, NullPointerException, ProfileDataException,ProviderException,RasterFormatException, SecurityException, SystemException, UndeclaredThrowableException,UnmodifiableSetException, UnsupportedOperationException34?(implements)?(concreteclass)?(implements)35List, Set, MapCollection?    ListSetMap36?J2EE37abstractmethodstatic,nativesynchronized?Click to buy NOW!PDF­XCHANGE­track.comClick to buy NOW!PDF­XCHANGE­track.com38length()? Stringlength()length()lengthStringlength()39Set?==equals()??Setiterator()Equals(