几百道常见Java初中级面试题

package hello.ant;
import java.sql.*;
public class jdbc{
String dbUrl="jdbc:oracle:thin:@127.0.0.1:1521:orcl";
String theUser="admin";
String thePw="manager";
Connection c=null ;
Statement conn;
ResultSet rs=null;

public jdbc(){
 try{
 Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
 c = DriverManager.getConnection(dbUrl,theUser,thePw);
 conn=c.createStatement();
 }catch(Exception e){
 e.printStackTrace();
 } 
}
 
public boolean executeUpdate(String sql){ 
try {
conn.executeUpdate(sql);
 return true;
 }
catch (SQLException e){
 e.printStackTrace();
 return false;
 } 
}
 
public ResultSet executeQuery(String sql){
 rs=null;
 try{
 rs=conn.executeQuery(sql);
}
catch (SQLException e){
 e.printStackTrace();
 }
 return rs;
 }
 
public void close(){
try{
 conn.close();
 c.close();
 }catch (Exception e){
 e.printStackTrace(); 
}
 }
 
public static void main(String[] args){
 ResultSet rs;
 jdbc conn = new jdbc();
 rs=conn.executeQuery("select * from test");
try{
 while (rs.next()) { 
System.out.println(rs.getString("id")); 
System.out.println(rs.getString("name"));
 } 
}catch(Exception e) {
 e.printStackTrace(); 
  } 
 } 
}
 

<%
int i=1;
int numPages=14;
String pages = request.getParameter("page") ; 
int currentPage = 1;
currentPage=(pages==null)?(1):{Integer.parseInt(pages)}
sql = "select count(*) from tables";
ResultSet rs = DBLink.executeQuery(sql) ; 
while(rs.next()) i = rs.getInt(1) ;
int intPageCount=1;
intPageCount=(i%numPages==0)?(i/numPages):(i/numPages+1);
int nextPage ;
int upPage; 
nextPage = currentPage+1;
if (nextPage>=intPageCount) nextPage=intPageCount;
upPage = currentPage-1; 
if (upPage<=1) upPage=1; 
rs.close(); 
sql="select * from tables"; 
rs=DBLink.executeQuery(sql);
i=0;
while((i<numPages*(currentPage-1))&&rs.next()){i++;}
%>
 
//输出内容
 
//输出翻页连接
 
合计:<%=currentPage%>/<%=intPageCount%><a href="List.jsp?page=1">第一页</a><a href="List.jsp?page=<%=upPage%>">上一页</a>
<%
for(int j=1;j<=intPageCount;j++){
if(currentPage!=j){
%>
<a href="list.jsp?page=<%=j%>">[<%=j%>]</a> 
<% 
}else{
out.println(j);
 } 
} 
%>
<a href="List.jsp?page=<%=nextPage%>">下一页</a><a href="List.jsp?page=<%=intPageCount%>">最后页 </a>

package test;
import java.io.*;
public class DOMTest{
 private String inFile = "c:\people.xml";
 private String outFile = "c:\people.xml";
 
public static void main(String args[]){
 new DOMTest(); 
}
 
public DOMTest(){
 try{
 javax.xml.parsers.DocumentBuilder builder = 
javax.xml.parsers.DocumentBuilderFactory.newInstance().newDocumentBuilder();
 org.w3c.dom.Document doc = builder.newDocument();
 org.w3c.dom.Element root = doc.createElement("老师");
 org.w3c.dom.Element wang = doc.createElement("王");
 org.w3c.dom.Element liu = doc.createElement("刘");
 wang.appendChild(doc.createTextNode("我是王老师"));
 root.appendChild(wang);
 doc.appendChild(root);
 javax.xml.transform.Transformer transformer =
javax.xml.transform.TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(javax.xml.transform.OutputKeys.ENCODING, "gb2312");
transformer.setOutputProperty(javax.xml.transform.OutputKeys.INDENT, "yes");

transformer.transform(new javax.xml.transform.dom.DOMSource(doc),
 new javax.xml.transform.stream.StreamResult(outFile));
}catch (Exception e){
 System.out.println (e.getMessage());
 } 
} 
}

<?xml version="1.0" encoding="gb2312"?> 
<person>
<name>王小明</name>
<college>信息学院</college>
<telephone>6258113</telephone>
<notes>男,1955年生,博士，95年调入海南大学</notes>
</person> 

事件回调类SAXHandler.java
import java.io.*; 
import java.util.Hashtable;
import org.xml.sax.*;
public class SAXHandler extends HandlerBase{
private Hashtable table = new Hashtable(); 
private String currentElement = null;
private String currentValue = null;
public void setTable(Hashtable table){
this.table = table;
} 
public Hashtable getTable(){
return table; 
}
public void startElement(String tag, AttributeList attrs)throws SAXException{
 currentElement = tag;
 }
 
public void characters(char[] ch, int start, int length)throws SAXException{
 currentValue = new String(ch, start, length);
 }
 
public void endElement(String name) throws SAXException{
 if (currentElement.equals(name))
 table.put(currentElement, currentValue);
 }
}
 
JSP内容显示源码,SaxXml.jsp:
 <HTML> 
<HEAD> 
<TITLE>剖析XML文件people.xml</TITLE> 
</HEAD> 
<BODY>
<%@ page errorPage="ErrPage.jsp"
contentType="text/html;charset=GB2312" %>
<%@ page import="java.io.*" %>
<%@ page import="java.util.Hashtable" %>
<%@ page import="org.w3c.dom.*" %>
<%@ page import="org.xml.sax.*" %>
<%@ page import="javax.xml.parsers.SAXParserFactory" %>
<%@ page import="javax.xml.parsers.SAXParser" %> 
<%@ page import="SAXHandler" %>
<%
File file = new File("c:\people.xml"); 
FileReader reader = new FileReader(file);
Parser parser;
SAXParserFactory spf = SAXParserFactory.newInstance();
SAXParser sp = spf.newSAXParser();
SAXHandler handler = new SAXHandler();
sp.parse(new InputSource(reader), handler);
Hashtable hashTable = handler.getTable();
out.println("<TABLE BORDER=2><CAPTION>教师信息表</CAPTION>"); 
out.println("<TR><TD>姓名</TD>" + "<TD>" + (String)hashTable.get(new String("name")) + "</TD></TR>"); 
out.println("<TR><TD>学院</TD>" + "<TD>" + (String)hashTable.get(new String("college"))+"</TD></TR>"); 
out.println("<TR><TD>电话</TD>" + "<TD>" + (String)hashTable.get(new String("telephone")) + "</TD></TR>"); 
out.println("<TR><TD>备注</TD>" + "<TD>" + (String)hashTable.get(new String("notes")) + "</TD></TR>");
out.println("</TABLE>"); 
%>
</BODY> 
</HTML>

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
}
 

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