J2EE全套笔试面试题（4文档终极汇总版）(8)

(String)hashTable.get(new String(\+ \ out.println(\备注\+ \+

(String)hashTable.get(new String(\+ \ out.println(\ %>

146、EJB的基本架构 答:一个EJB包括三个部分: Remote Interface 接口的代码 package Beans;

import javax.ejb.EJBObject; import java.rmi.RemoteException; public interface Add extends EJBObject {

//some method declare }

Home Interface 接口的代码 package Beans;

import java.rmi.RemoteException; import jaax.ejb.CreateException; import javax.ejb.EJBHome;

public interface AddHome extends EJBHome {

//some method declare }

EJB类的代码 package Beans;

import java.rmi.RemoteException; import javax.ejb.SessionBean; import javx.ejb.SessionContext;

public class AddBean Implements SessionBean {

//some method declare }

147、如何校验数字型?

var re=/^\\d{1,8}$|\\.\\d{1,2}$/; var str=document.form1.all(i).value; var r=str.match(re); if (r==null) {

sign=-4; break;

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} else{

document.form1.all(i).value=parseFloat(str); }

148、将一个键盘输入的数字转化成中文输出

(例如:输入:1234567 输出:一百二拾三万四千五百六拾七) 用java语言实现,,请编一段程序实现! public class Reader { private String strNum;

private String strNumChFormat; private String strNumTemp; private int intNumLen; private String strBegin; public Reader(String strNum) { this.strNum = strNum; }

public boolean check(String strNum) { boolean valid = false;

if (strNum.substring(0,1).equals(\ this.strNum = strNum.substring(1); } try {

new Double(strNum); valid = true; }

catch (NumberFormatException ex) {

System.out.println(\ }

return valid; }

public void init() { strNumChFormat = \

intNumLen = strNum.length(); strNumTemp = strNum;

strNumTemp = strNumTemp.replace('1', '一'); strNumTemp = strNumTemp.replace('2', '二'); strNumTemp = strNumTemp.replace('3', '三'); strNumTemp = strNumTemp.replace('4', '四'); strNumTemp = strNumTemp.replace('5', '五'); strNumTemp = strNumTemp.replace('6', '六'); strNumTemp = strNumTemp.replace('7', '七'); strNumTemp = strNumTemp.replace('8', '八'); strNumTemp = strNumTemp.replace('9', '九');

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strNumTemp = strNumTemp.replace('0', '零'); strNumTemp = strNumTemp.replace('.', '点'); strBegin = strNumTemp.substring(0, 1); }

public String readNum() { if (check(strNum)) { init(); try {

for (int i = 1, j = 1, k = 1; i < intNumLen; i++) {

if (strNumTemp.charAt(intNumLen - 1) == '零' && i == 1) { strNumChFormat = \位\ }

else if (strNumTemp.charAt(intNumLen - i) == '零' && j == 1) { strNumChFormat = \位\ }

else if (strNumTemp.charAt(intNumLen - i) == '点') { j = 1; k = 1;

strNumChFormat = strNumTemp.charAt(intNumLen - i) + strNumChFormat; continue; } else {

strNumChFormat = strNumTemp.charAt(intNumLen - i) + strNumChFormat; }

if (strNumTemp.charAt(intNumLen - i - 1) != '位' && strNumTemp.charAt(intNumLen - i - 1) != '零') { if (j == 1 && i < intNumLen) {

strNumChFormat = '拾' + strNumChFormat; }

else if (j == 2 && i < intNumLen) { strNumChFormat = '百' + strNumChFormat; }

else if (j == 3 && i < intNumLen) { strNumChFormat = '千' + strNumChFormat; } }

if (j == 4 && i < intNumLen) { j = 0; }

if (k == 4 && i < intNumLen) {

strNumChFormat = '万' + strNumChFormat; }

else if (k == 8 && i < intNumLen) { k = 0;

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strNumChFormat = '亿' + strNumChFormat; } j++; k++; }

while (strNumChFormat.indexOf(\位\

strNumChFormat = strNumChFormat.replaceAll(\位\ }

if (strNumChFormat.substring(0, 2) == \一拾\

strNumChFormat = strNumChFormat.substring(1, strNumChFormat.length()); }

if (strNumChFormat.indexOf(\点\ String rebegin = strNumChFormat.substring(0, strNumChFormat.indexOf(\点\

String relast = strNumChFormat.substring(strNumChFormat.indexOf(\点\ strNumChFormat.length());

for (int i = 1; i <= relast.length(); i++) { relast = relast.replaceAll(\拾\ relast = relast.replaceAll(\百\ relast = relast.replaceAll(\千\ relast = relast.replaceAll(\万\ relast = relast.replaceAll(\亿\ }

strNumChFormat = rebegin + relast; } }

catch (ArrayIndexOutOfBoundsException ex) { ex.printStackTrace(); }

catch (Exception ex) { ex.printStackTrace(); }

int off = strNumChFormat.indexOf(\点\

strNumChFormat = strBegin + strNumChFormat.substring(0); } else {

strNumChFormat = \ }

return strNumChFormat; }

public static void main(String args[]) { try {

String number = args[0].toString();

System.out.println(\

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Reader reader = new Reader(number);

System.out.println(\ }

catch (Exception ex) {

System.out.println(\ } } }

149、JAVA代码查错 1.

abstract class Name { private String name;

public abstract boolean isStupidName(String name) {} }

大侠们，这有何错误?

答案: 错。abstract method必须以分号结尾，且不带花括号。 2.

public class Something { void doSomething () { private String s = \ int l = s.length(); } } 有错吗?

答案: 错。局部变量前不能放置任何访问修饰符 (private，public，和protected)。final可以用来修饰局部变量

(final如同abstract和strictfp，都是非访问修饰符，strictfp只能修饰class和method而非variable)。 3.

abstract class Something {

private abstract String doSomething (); }

这好像没什么错吧?

答案: 错。abstract的methods不能以private修饰。abstract的methods就是让子类implement(实现)具体细节的，怎么可以用private把abstract

method封锁起来呢? (同理，abstract method前不能加final)。 4.

public class Something { public int addOne(final int x) { return ++x; } }

这个比较明显。

答案: 错。int x被修饰成final，意味着x不能在addOne method中被修改。

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