学习jsp第四天

原创 于 2012-02-04 14:14:46 发布 · 321 阅读 · 0 ·
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文章标签：

#jsp #string #exception #import #null #action

 也许是周六的关系，也或许是我的三分钟热血已经开始凉了，今天的学习氛围相当的差劲，已经完全无法提起精神来学习。不过还好，挣扎着终于把简单的数据修改和删除部分做完了。内容少的可怜，只是添加了一个页面，把之前的代码稍加更改了一些。虽然能看到明显的BUG，可提不起兴趣解决。想起今天本该休息，值因为下周社长要从日本来此考察，使得同事们只好稍作表现，周六依然来公司混时光，想想可叹，这可悲的人生。

情绪的话语少说，先把今天所做的那么一点成绩拿出来摆给大家看看。

这次一共涉及6个页面，其中4个.java为结尾的页面，2个.jsp为结尾的页面。java文件其中一个为数据库连接类，一个是负责（修改，删除，插入）的管理类，还有一个是列表搜索类，最后一个是判断类（在这个类中判断是进行新增还是进行修改），jsp页面一个是显示列表的页面，一个是新增或修改的页面。

db文件，此数据库类并非本人所写：

package class4.java;

import java.sql.*;

public class AntDb {

 private String DRIVER;
 private String HOST;
 private String USR;
 private String PWD;
 private Connection Condb;
 private Statement stmt;
 private PreparedStatement pStmt;

 public AntDb(String DRIVER, String HOST, String USR, String PWD){
  this.DRIVER = DRIVER;
  this.HOST = HOST;
  this.USR = USR;
  this.PWD = PWD;
 }

 public AntDb(){
  DRIVER = "org.postgresql.Driver";
  HOST = "jdbc:postgresql://localhost:5432/AntTest?charSet=UTF-8";
  USR = "postgres";
  PWD = "";
 }

 public String ConnectDB() throws Exception{
  String strtmp ="";
  try{
   Class.forName(DRIVER);
   Condb = DriverManager.getConnection(HOST, USR, PWD);
   Condb.setAutoCommit(false);
   stmt = Condb.createStatement();
  }catch(Exception serrmsg){
   strtmp = serrmsg.toString();
  }
  return strtmp;
 }

 public String TransactionDB(int i) throws Exception{
  String strtmp="";
  try{
   if (i == 0){
    Condb.commit();
    System.out.println("操作成功");
   }else{
    Condb.rollback();
    System.out.println("回滚数据成功");
   }//else
  }catch(Exception e){
   strtmp = e.toString();
  }
  return strtmp;
 }

 public String disconnect(ResultSet Rset) throws Exception{
  String strtmp = "";
  try{
   if ( Rset != null) Rset.close();
   if ( stmt != null ) stmt.close();
   if (pStmt != null) pStmt.close();
  if ( Condb != null ) Condb.close();
  }catch(Exception e){
   strtmp = e.toString();
  }
  return strtmp;
 }

 public ResultSet SelectSql(String sql,StringBuffer sErr) throws Exception {
  int inttmp = 0;
  ResultSet Rset = null;
  inttmp = sErr.length();
  if (inttmp > 0){sErr.delete(0,inttmp);}
  try {
   Rset = stmt.executeQuery(sql);
  }catch(Exception e) {
   sErr.append(e.toString());
  }
  return Rset;
 }

 public String ExcuteSql(String sql) throws Exception {
  int iResult = 0;
  String strtmp = "";
  try {
   iResult = stmt.executeUpdate(sql);
  }catch(Exception e) {
   strtmp = e.toString();
  }
  return strtmp;
 }

 public String AddSqlBatch(String sql) throws Exception {
  String strtmp = "";
  try {
    stmt.addBatch(sql);
  }catch(Exception e) {
   strtmp = e.toString();
  }
  return strtmp;
 }

 public String ExcuteSqlBatch() throws Exception {
  int iResult[];
  String strtmp = "";
  try {
   iResult=stmt.executeBatch();
  }catch(Exception e) {
   strtmp = e.toString();
  }
  return strtmp;
 }

 public PreparedStatement getPreparedStatement(String sql) throws Exception {
  try {
   pStmt = Condb.prepareStatement(sql);
  }catch(Exception e) {
   e.printStackTrace();
  }
  return pStmt;
 }

 public String ExeSqlBatch() throws Exception {
  int iResult[];
  String strtmp = "";
  try {
   iResult=pStmt.executeBatch();
  }catch(Exception e) {
   strtmp = e.toString();
  }
  return strtmp;
 }
}

增删改类：

package class4.java;

import java.io.*;
import java.sql.*;
import java.util.*;
import java.util.Date;

import javax.servlet.*;
import javax.servlet.http.*;

import class4.java.*;

public class AntTestEditer extends HttpServlet{
 private final String transPath        = "/servlet/AntTest";
 private static final String CONTENT_TYPE      = "text/html;charset=utf-8";
 private static final String sendPath = null;

 public void doGet( HttpServletRequest  request,HttpServletResponse response ) throws IOException,ServletException{
  doPost(request,response);
 }

 public void doPost( HttpServletRequest  request,HttpServletResponse response ) throws IOException,ServletException{
  String action = request.getParameter("action");
  String uName = request.getParameter("uname");
  String uKey = request.getParameter("ukey");

  try {
   AntDb dbAccess = new AntDb();
   String sendPath = "";
   Boolean chkFlg=true;
   String strRetnResult=dbAccess.ConnectDB();
   response.setContentType(CONTENT_TYPE);
   ServletContext context = getServletContext();
   Boolean err=true;

   if(action==null){
    action="";
   }else{
    String sql="";
    try{
     if("writ".equals(action)){
      if(uName != null && uName != ""){
       String AntDate = this.getDate();
       sql = "INSERT INTO \"AntTestDataBase\"(\"AntName\",\"AntDate\",\"AntStatu\") VALUES ('"+uName+"', '"+AntDate+"', 1)";
       //System.out.println(sql);
      }else{
       err = false;
      }
     }else if("edit".equals(action)){
      if(uName != null & uKey != null){
       sql = "update \"AntTestDataBase\" set \"AntName\"='"+uName+"' where \"AntKey\"='"+uKey+"'";
       //System.out.println(sql);
      }else{
       err=false;
      }
     }else if("del".equals(action)){
      if(uKey != null){
       sql = "delete from \"AntTestDataBase\" where \"AntKey\"='"+uKey+"'";
       //System.out.println(sql);
      }else{
       err=false;
      }
     }
     if(err){
      String rSel = dbAccess.ExcuteSql(sql);
      if (rSel.length() != 0) {
       chkFlg=false;
      }
     }
    }catch(Exception e){
     e.printStackTrace();
    }finally{
     if(chkFlg){
      sendPath= this.transPath;
      dbAccess.TransactionDB(0);
     }else{
      dbAccess.TransactionDB(1);
     }
     dbAccess.disconnect(null);
    }
   }

   RequestDispatcher dispatcher = context.getRequestDispatcher(sendPath);
   dispatcher.forward(request,response);

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

 private String getDate() {
  java.text.SimpleDateFormat GetDate=new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  java.util.Date date=new java.util.Date();
  return GetDate.format(date);
 }
}

输入或新增判断类：

package class4.java;

import java.io.*;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.HashMap;

import javax.servlet.*;
import javax.servlet.http.*;

import class4.java.*;

public class AntTestWrit extends HttpServlet{
 private static final long serialVersionUID     = 1L;
 private final String sendPath        = "/class4/jsp/jietTestWrit.jsp";
 private static final String CONTENT_TYPE      = "text/html;charset=utf-8";

 public void doGet( HttpServletRequest  request,HttpServletResponse response ) throws IOException,ServletException{
  doPost(request,response);
 }

 public void doPost( HttpServletRequest  request,HttpServletResponse response ) throws IOException,ServletException{
  HttpSession session = request.getSession(true);
  AntDb dbAccess = new AntDb();
  Boolean chkFlg=true;

  String uId = request.getParameter("uid");
  String uName="";
  String mode = "writ";


  try {
   response.setContentType(CONTENT_TYPE);
   ServletContext context = getServletContext();

   HashMap<String, String> AntTestHm = new HashMap<String, String>();

   if(uId != null){
    mode = "edit";
    String strRetnResult=dbAccess.ConnectDB();
    StringBuffer searchErrMsg = new StringBuffer();
    ResultSet rsetSel = dbAccess.SelectSql("select * from \"AntTestDataBase\" where \"AntKey\"='"+uId+"'", searchErrMsg);
    if (searchErrMsg.toString().length() == 0) {
     while (rsetSel.next()) {
      uId = (rsetSel.getString("AntKey") != null) ? (rsetSel.getString("AntKey").trim()) : "";
      uName = (rsetSel.getString("AntName") != null) ? (rsetSel.getString("AntName").trim()) : "";

      AntTestHm.put("ukey", uId);
      AntTestHm.put("uname", uName);
     }
    }
   }

   AntTestHm.put("mode", mode);

   session.removeAttribute("AntTestHm");
   session.setAttribute("AntTestHm", AntTestHm);

   RequestDispatcher dispatcher = context.getRequestDispatcher(sendPath);
   dispatcher.forward(request,response);

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

列表搜索类：

package class4.java;

import java.io.*;
import java.sql.*;
import java.util.*;
import java.util.Date;

import javax.servlet.*;
import javax.servlet.http.*;

import class4.java.*;

public class jietTest extends HttpServlet{
 private final String sendPath        = "/class4/java/antTest.jsp";
 private static final String CONTENT_TYPE      = "text/html;charset=utf-8";

 public void doGet( HttpServletRequest  request,HttpServletResponse response ) throws IOException,ServletException{
  doPost(request,response);
 }

 public void doPost( HttpServletRequest  request,HttpServletResponse response ) throws IOException,ServletException{
  HttpSession session = request.getSession(true);
  AntDb dbAccess = new AntDb ();

  List<HashMap<String,String>> AntTestList = new ArrayList<HashMap<String, String>>();
  HashMap<String,String> AntTestHm;

  try {
   response.setContentType(CONTENT_TYPE);

   Boolean chkFlg=true;
   String strRetnResult=dbAccess.ConnectDB();
   ServletContext context = getServletContext();

   StringBuffer searchErrMsg = new StringBuffer();
   ResultSet rsetSel = dbAccess.SelectSql("select * from \"AntTestDataBase\" order by \"AntKey\" desc limit 10", searchErrMsg);

   if (searchErrMsg.toString().length() == 0) {
    while (rsetSel.next()) {
     String AntKey = (rsetSel.getString("AntKey") != null) ? (rsetSel.getString("AntKey").trim()) : "";
     String AntName = (rsetSel.getString("AntName") != null) ? (rsetSel.getString("AntName").trim()) : "";
     String AntYmd = (rsetSel.getString("AntDate") != null) ? (rsetSel.getString("AntDate").trim()) : "";

     AntTestHm = new HashMap<String, String>();
     AntTestHm.put("AntKey", AntKey);
     AntTestHm.put("AntName", AntName);
     AntTestHm.put("AntYmd", AntYmd);
     AntTestList.add(AntTestHm);

    }
   }

   session.removeAttribute("AntTestList");
   session.setAttribute("AntTestList", AntTestList);

   RequestDispatcher dispatcher = context.getRequestDispatcher(sendPath);
   dispatcher.forward(request,response);

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

 private String getDate() {
  java.text.SimpleDateFormat GetDate=new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  java.util.Date date=new java.util.Date();
  return GetDate.format(date);
 }
}

列表显示jsp页：

<%@ page import="java.io.*,java.util.*,java.lang.Character.UnicodeBlock" contentType="text/html; charset=utf-8" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Ant JAVA练习页面</title>
<script type="text/javascript">
function onclicks(){
 document.location.href='/class4/servlet/AntTestWrit';
}
</script>
</head>

<body>
<%
List<HashMap<String,String>> AntTestList = (ArrayList<HashMap<String, String>>) session.getAttribute("AntTestList");
%>
<table>
<%
for (int loopCnt = 0; loopCnt < AntTestList.size();loopCnt++) {
 HashMap<String, String> hm = AntTestList.get(loopCnt);
 String AntKey = hm.get("AntKey");
 String AntName = hm.get("AntName");
 String AntYmd = hm.get("AntYmd");
%>
<tr><td width="200"><%=AntKey %></td><td width="200"><%=AntName %></td><td width="200"><%=AntYmd %></td><td><a href="jietTestWrit?uid=<%=AntKey %>">Edit</a></td><td><a href="jietTestEditer?ukey=<%=AntKey %>&action=del">Delete</a></td></tr>
<%
}
%>
</table>
<p><input type="button" value="click" onclick="onclicks();" /></p>
</body>
</html>

新增或修改页：

<%@ page import="java.io.*,java.util.*,java.lang.Character.UnicodeBlock" contentType="text/html; charset=utf-8" %>
<html>
<head>
<title>Ant first web progrem for jsp</title>
</head>
<body>
<%
HashMap<String, String> hm = (HashMap<String, String>)session.getAttribute("AntTestHm");
String mode = hm.get("mode");
String uKey = hm.get("ukey");
if(uKey==null){
 uKey="";
}
String uName = hm.get("uname");
if(uName==null){
 uName="";
}
%>
<form action="./jietTestEditer" name="AntTest" method="POST">
<input type="hidden" name="action" value="<%=mode %>" />
<input type="hidden" name="ukey" value="<%=uKey %>" />
<table>
 <tr>
  <td colspan="a"><label>name:</label><input type="text" name="uname" value="<%=uName %>" /></td>
 </tr>
 <tr>
  <td><input type="submit" value="<%=mode %>" /></td>
 </tr>
</table>
</form>
</body>
</html>

 

由于我制作的时候是在其他文档下，所以当我复制到文章内以后修改了一些路径。但我不能保证已经将所有的路径修改完成，如果在你进行测试的时候出现错误。可查看路径，以及类的名字是否和文档名等条件符合。不过，可以确定的是，程序的思路，以及程序内部的脚本是没有问题的。

明天周日，我将休息一天，而后天，如果有空，我将着手学习java的基础知识，以及将本程序暂时为止出现的BUG给与更正。

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