Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object?（）A、When using versions of Java technology earlier than 5.0.B、When sharing a StringBuffer among multiple threads.C、When using the java.io class StringBufferInputStream.D、When you plan to reuse the StringBuffer to build more than one string.
Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object?（）
- A、When using versions of Java technology earlier than 5.0.
- B、When sharing a StringBuffer among multiple threads.
- C、When using the java.io class StringBufferInputStream.
- D、When you plan to reuse the StringBuffer to build more than one string.
相关考题：
Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object?() A.When using versions of Java technology earlier than 5.0.B.When sharing a StringBuffer among multiple threads.C.When using the java.io class StringBufferInputStream.D.When you plan to reuse the StringBuffer to build more than one string.
Given a class whose instances, when found in a collection of objects, are sorted by using the compareTo()method, which two statements are true?() A.The class implements java.lang.Comparable.B.The class implements java.util.Comparator.C.The interface used to implement sorting allows this class to define only one sort sequence.D.The interface used to implement sorting allows this class to define many different sort sequences.
What two situations could require the use of multiple routing protocols? () A. when all equipment is manufactured by CiscoB. when there are multiple paths to destination networksC. because having multiple routing protocols confuses hackersD. when migrating from an older Interior Gateway Protocol (IGP) to a new IGPE. when using UNIX host - based routersF. when smaller broadcast domains are desired
What two situations could require the use of multiple routing protocols? （）A、when all equipment is manufactured by CiscoB、when there are multiple paths to destination networksC、because having multiple routing protocols confuses hackersD、when migrating from an older Interior Gateway Protocol (IGP) to a new IGPE、when using UNIX host - based routersF、when smaller broadcast domains are desired
When you are designing a Web application， which options define how rich text displays in a browser？（）A、"Using HTML"B、"Using Java Applet"C、"Using AJAX Control"D、"Using Best Fit for OS"
Whichtwo scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object？（）A、When using versions of Java technology earlier than 5.0.B、When sharing a StringBuffer among multiple threads.C、When using the java.io class StringBufferInputStream.D、When you plan to reuse the StringBuffer to build more than one string.E、Enitiation of separate design processes to the separation of users
public class TestString3 { public static void main（String[] args） { // insert code here System.out.println（s）； } } Which two code fragments， inserted independently at line 3， generate the output 4247？（）A、 String s = “123456789”； s = （s-”123”）.replace（1，3，”24”） - “89”；B、 StringBuffer s = new StringBuffer（”123456789”）； s.delete（0，3）.replace（ 1，3， “24”）.delete（4，6）；C、 StringBuffer s = new StringBuffer（”123456789”）； s.substring（3，6）.delete（ 1 ，3）.insert（1， “24”）；D、 StringBuilder s = new StringBuilder（”123456789”）； s.substring（3，6）.delete（ 1 ，2）.insert（ 1， “24”）；E、 StringBuilder s = new StringBuilder（”123456789”）； s.delete（0，3）.delete（ 1 ，3）.delete（2，5）.insert（ 1， “24”）；
Your web application requires the adding and deleting of many session attributes during a complex usecase. A bug report has come in that indicates that an important session attribute is being deleted too soonand a NullPointerException is being thrown several interactions after the fact. You have decided to create asession event listener that will log when attributes are being deleted so you can track down when theattribute is erroneously being deleted. Which listener class will accomplish this debugging goal？（）A、Create an HttpSessionAttributeListener class and implement the attributeDeleted method and log the attribute name using the getName method on the event object.B、Create an HttpSessionAttributeListener class and implement the attributeRemoved method and log the attribute name using the getName method on the event object.C、Create an SessionAttributeListener class and implement the attributeRemoved method and log the attribute name using the getAttributeName method on the event object.D、Create an SessionAttributeListener class and implement the attributeDeleted method and log the attribute name using the getAttributeName method on the event object.
When multiple PPP over Ethernet subscribers connect using the same DSL modem, which two attributes does the ERX use to differentiate between subscribers? （）(Choose two.)A、PPP session IDB、subscriber nameC、source MAC addressD、destination MAC address
Which statements concerning the methods notify（） and notifyAll（） are true？ A、Instances of class Thread have a method called notify（）.B、A call to the method notify（） will wake the thread that currently owns the monitor of the object.C、The method notify（） is synchronized.D、The method notifyAll（） is defined in class Thread.E、When there is more than one thread waiting to obtain the monitor of an object， there is no way to be sure which thread will be notified by the notify（） method.
Which of the following is eliminated when using SATA instead of PATA technology？（）A、Jumper selectionB、Power connectorC、Data port connectorD、Hard drive LEDs
Given this method in a class： public String toString（） { StringBuffer buffer = new StringBuffer（）； buffer.append（‟‟）； buffer.append（this.name）； buffer.append（‟‟）； return buffer.toString（）； } Which is true？（） A、 This code is NOT thread-safe.B、 The programmer can replace StringBuffer with StringBuilder with no other changes.C、 This code will perform well and converting the code to use StringBuilder will not enhance the performance.D、 This code will perform poorly. For better performance， the code should be rewritten： return ““+ this.name + “”；
Which methods from the String and StringBuffer classes modify the object on which they are called？（） A、The charAt（） method of the String class.B、The toUpperCase（） method of the String class.C、The replace（） method of the String class.D、The reverse（） method of the StringBuffer class.E、The length（） method of the StringBuffer class.
Given a class whose instances， when found in a collection of objects， are sorted by using the compareTo（） method， which two statements are true？（）A、The class implements java.lang.Comparable.B、The class implements java.util.Comparator.C、The interface used to implement sorting allows this class to define only one sort sequence.D、The interface used to implement sorting allows this class to define many different sort sequences.
Your web application uses a simple architecture in which servlets handle requests and then forward to aJSP using a request dispatcher. You need to pass information calculated in the servlet to the JSP for view generation.This information must NOT be accessible to any other servlet，JSP or session in the webapp. Which two techniques can you use to accomplish this goal？（）A、Add attributes to the session object.B、Add attributes on the request object.C、Add parameters to the request object.D、Use the pageContext object to add request attributes.E、Add parameters to the JSP’s URL when generating the request dispatcher.
public class MyLogger { private StringBuilder logger = new StringBuuilder（）； public void log（String message， String user） { logger.append（message）； logger.append（user）； } } The programmer must guarantee that a single MyLogger object works properly for a multi-threaded system. How must this code be changed to be thread-safe？（） A、 synchronize the log methodB、 replace StringBuilder with StringBufferC、 No change is necessary， the current MyLogger code is already thread-safe.D、 replace StringBuilder with just a String object and use the string concatenation （+=） within the log method
Which object is added to a form module when you copy the reusable calender class?（）A、List icon B、Object group C、PL/SQL library D、Key-Listval trigger
Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object？（）A、When using versions of Java technology earlier than 5.0.B、When sharing a StringBuffer among multiple threads.C、When using the java.io class StringBufferInputStream.D、When you plan to reuse the StringBuffer to build more than one string.
In which situation would you use static database registration for a listener（）A、when multiple databases are to be registered with the listenerB、when DBAs need to connect remotely to start up the database instanceC、when users need to connect the database instance using the host naming methodD、when the database instance that is to be registered with the listener is configured in shared server mode
When is an implicit anchor created?（）A、When an object is enclosed by another object. B、When a page break after pagination property is enabled. C、When a link is created between two objects. D、When a keep with anchoring object pagination property is enabled.
单选题Given this method in a class： public String toString（） { StringBuffer buffer = new StringBuffer（）； buffer.append（‟‟）； return buffer.toString（）； } Which is true？（）A This code is NOT thread-safe.B The programmer can replace StringBuffer with StringBuilder with no other changes.C This code will perform well and converting the code to use StringBuilder will not enhance the performance.D This code will perform poorly. For better performance， the code should be rewritten： return ““+ this.name + “”；
单选题public class MyLogger { private StringBuilder logger = new StringBuuilder（）； public void log（String message， String user） { logger.append（message）； logger.append（user）； } } The programmer must guarantee that a single MyLogger object works properly for a multi-threaded system. How must this code be changed to be thread-safe？（）A synchronize the log methodB replace StringBuilder with StringBufferC No change is necessary， the current MyLogger code is already thread-safe.D replace StringBuilder with just a String object and use the string concatenation （+=） within the log method
多选题Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object?（）AWhen using versions of Java technology earlier than 5.0.BWhen sharing a StringBuffer among multiple threads.CWhen using the java.io class StringBufferInputStream.DWhen you plan to reuse the StringBuffer to build more than one string.
多选题Whichtwo scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object？（）AWhen using versions of Java technology earlier than 5.0.BWhen sharing a StringBuffer among multiple threads.CWhen using the java.io class StringBufferInputStream.DWhen you plan to reuse the StringBuffer to build more than one string.EEnitiation of separate design processes to the separation of users
多选题Your web application uses a simple architecture in which servlets handle requests and then forward to aJSP using a request dispatcher. You need to pass information calculated in the servlet to the JSP for view generation.This information must NOT be accessible to any other servlet，JSP or session in the webapp. Which two techniques can you use to accomplish this goal？（）AAdd attributes to the session object.BAdd attributes on the request object.CAdd parameters to the request object.DUse the pageContext object to add request attributes.EAdd parameters to the JSP’s URL when generating the request dispatcher.
单选题Which methods from the String and StringBuffer classes modify the object on which they are called？（）AThe charAt（） method of the String class.BThe toUpperCase（） method of the String class.CThe replace（） method of the String class.DThe reverse（） method of the StringBuffer class.EThe length（） method of the StringBuffer class.
单选题When using the radar for navigating（）.Athe best fix is obtained by using a tangent bearing and a rangeBand using two radar ranges for a fix，the objects of the ranges should be close to reciprocal bearingsCand using ranges，the most rapidly changing range should be measured lastDand crossing a radar range of one object with the visual bearing of a second object，the two objects should be 80°to 110°apart