Tomcat+mysql連接池配置

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  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
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  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
--><!-- The contents of this file will be loaded for each web application --><Context>

    <!-- Default set of monitored resources -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->

    <!-- Uncomment this to enable Comet connection tacking (provides events
         on session expiration as well as webapp lifecycle) -->
    <!--
    <Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
    -->
    <Resource name="jdbc/mysql" 
auth="Container" 
type="javax.sql.DataSource" 
maxActive="50" 
maxIdle="10" 
maxWait="5000" 
username="root" 
password="sql123" 
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/labtmp?useUnicode=true&amp;characterEncoding=UTF-8&amp;zeroDateTimeBehavior=convertToNull" />
</Context>

 

package com.my;

import java.io.InputStream;
import java.sql.*;
import java.util.ArrayList;
import javax.sql.*;
import javax.naming.*;

public class Mysql {
    private Connection conn = null;
    private PreparedStatement ps = null;
    private Statement stm = null;

    // constructor 1
    public Mysql() throws Exception {
             
        conn=lookForConnection();
        if(conn!=null)
           stm = conn.createStatement();
        else
           System.out.println("get DB Connection Failure!");
    }

    // constructor 2
    public Mysql(String sql) throws Exception {
        conn=lookForConnection();  
         if(conn!=null)
         {   
             this.prepareStatement(sql);
             stm = conn.createStatement();
         }
         else
             System.out.println("get DB Connection Failure!");
    }
    
    private Connection lookForConnection()throws Exception
    {
        DataSource ds = null; 
         try{ 
             InitialContext ctx=new InitialContext(); 
             ds=(DataSource)ctx.lookup("java:comp/env/jdbc/mysql"); 
             Connection con= ds.getConnection();  
             return con;
         }
        catch(Exception ex){
             ex.printStackTrace();
             return null;
        } 
    }
    public void prepareStatement(String sql) throws SQLException {
        ps = conn.prepareStatement(sql);
    }

    public void clearParameters() throws SQLException {
        ps.clearParameters();
    }

    // return the connection object
    public Connection getConnection() {
        return conn;
    }

    // return the preparedstatement
    public PreparedStatement getPreparedStatement() {
        return ps;
    }

    // return the set of query
    public ResultSet executeQuery(String sql) throws SQLException {
        if (stm != null) {
            return stm.executeQuery(sql);
        } else
            return null;
    }

    // return the set of query
    public ResultSet executeQuery() throws SQLException {
        if (ps != null) {
            return ps.executeQuery();
        } else
            return null;
    }

    // execute the operation of update
    public void executeUpdate(String sql) throws SQLException {
        if (stm != null)
            stm.executeUpdate(sql);
        else
           System.out.println("the Statement is null");
    }

    // execute the operation of update
    public void executeUpdate() throws SQLException {
        if (ps != null)
        {
          ps.executeUpdate();
        }
        else
            System.out.println("the prepareStatement is null");   
    }

    // close the connection and free resource
    public void closeCon() throws SQLException {
        if (stm != null) {
            stm.close();
            stm = null;
        }
        if (ps != null) {
            ps.close();
            ps = null;
        }
        conn.close();
        conn = null;
    }

    // lock the table
    public boolean lockTable(String table, String privilege)throws SQLException {
        String locksql = "lock tables " + table + " " + privilege;
            if(this.executeQuery(locksql)!=null)
            {
                // System.out.println("lock");
                return true;
            }
            else
            return false;
    }

    // unlock the table
    public boolean unLockTable() throws SQLException{
        String unlocksql = "unlock tables ";
        if(this.executeQuery(unlocksql)!=null)
        {
            // System.out.println("unlock");
            return true;
        }
        else
            return false;
    }

    // set the parameter
    public void setString(int index, String value) throws SQLException {
        ps.setString(index, value);
    }

    public void setInt(int index, int value) throws SQLException {
        ps.setInt(index, value);
    }

    public void setBoolean(int index, boolean value) throws SQLException {
        ps.setBoolean(index, value);
    }

    public void setDate(int index, Date value) throws SQLException {
        ps.setDate(index, value);
    }

    public void setLong(int index, long value) throws SQLException {
        ps.setLong(index, value);
    }

    public void setFloat(int index, float value) throws SQLException {
        ps.setFloat(index, value);
    }
    public void setBinaryStream(int index,InputStream in,int length) throws SQLException {
        ps.setBinaryStream(index,in,length);
        }
}

 

我的環境：

 Tomcat7.0.22，Mysql5.5，Windows xp Sp3

 最近需要在tomcat下配置mysql的連接池，在網上找了些資料參考了下，不同的版本tomcat配置介紹都略有不同，下面我介紹一下我配置的方法。

 1.首先，要安裝JDK1.6,Tomcat,mysql等，這些就不在此多說了。

  值得注意的是，mysql表字符集設置,很有可能在客戶端和JSP中亂碼,可參考文章:

  http://c02949.blog.163.com/blog/static/485037200962345218147/ 

  我是在eclipse下布署運行Tomcat的，在eclipse的window-->preference--->Server里，右面的里面添加tomcat的路徑，指定jdk,然后在下面的servers選項卡里新建一個服務器，這時候就會在eclipse的project explore中生成一個Servers項目

 

 

   2.在context.xml的<context></context>之間添加連接池如下:

 <Resource name="jdbc/mysql"

auth="Container" 
type="javax.sql.DataSource" 
maxActive="50"

maxIdle="10"

maxWait="5000" 
username="你的mysql用戶"

password="你的mysql密碼" 

driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost/dbname?useUnicode=true&amp;characterEncoding=UTF-8&amp;zeroDateTimeBehavior=convertToNull"/>

<WatchedResource>WEB-INF/web.xml </WatchedResource>  

XML里 & 要用&amp ;替代，不然會被過濾掉。

 

配置文件中Resource標簽中各屬性的含義：

driverClassName - JDBC 所用到的數據庫驅動的類全名.

maxActive - 連接池在同一時刻內所提供的最大活動連接數。

maxIdle - 連接池在空閑時刻保持的最大連接數.

maxWait - 當發生異常時數據庫等待的最大毫秒數 (當沒有可用的連接時).

password - 連接數據庫的密碼.

url - 連接至驅動的URL. (為了向后兼容, DRIVERNAME也被允許.)

username - 數據庫用戶名.

各種配置方式的范圍也應該是不一樣的。我在這就不細說了，總之就是在Context標簽下面配置個Resource標簽即可。

 

我的配置：

最后，將mysql 的jdbc驅動復制到配置tomcat下的lib目錄;

OK,到此tomcat就配置完了,接下來就是新建工程，測試:

3.打開Eclipse其手工建個WEB project(我的工程名AJAX),加入mysql JDBC驅動(我的這步沒加入也可以正常運行);

配置WEB-INFO下面的web.xml文件：

<web-app></web-app>之間加入:
<resource-ref> 
       <description>DB Connection</description> 
       <res-ref-name>jdbc/mysql</res-ref-name> 
       <res-type>javax.sql.DataSource</res-type> 
       <res-auth>Container</res-auth> 
    </resource-ref>

 我的配置：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>AJAX</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <resource-ref> 
       <description>DB Connection</description> 
       <res-ref-name>jdbc/mysql</res-ref-name> 
       <res-type>javax.sql.DataSource</res-type> 
       <res-auth>Container</res-auth> 
    </resource-ref>
</web-app>

 

注意的地方: context.xml文件中的name="jdbc/mysql"要和web.xml中的<res-ref-name>jdbc/mysql</res-ref-name>要一致;

新建JSP文件：

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ page import="java.sql.*"%> 
<%@ page import="javax.sql.*"%> 
<%@ page import="javax.naming.*"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
   <head>
<title>mysql連接池測試</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0"> 
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
   </head>
  
   <body> 
<%  
out.print("我的測試開始<br>"); 
DataSource ds = null; 
Connection conn=null;
       try{ 
InitialContext ctx=new InitialContext(); 
ds=(DataSource)ctx.lookup("java:comp/env/jdbc/mysql"); 
conn = ds.getConnection();  

    }catch(Exception ex){
     ex.printStackTrace();
    } 
%>  
<%   
    if(conn!=null){ 
%> 
     <%= conn %>;  
<% 
    } 
%> 
   </body>
</html>

 調試，運行，如果配置成功，則會在網頁中輸出以下內容：

這樣就配置完成了。

下面附上我寫的數據操作類（Mysql.java）：

 

package com.my;

import java.io.InputStream;
import java.sql.*;
import java.util.ArrayList;
import javax.sql.*;
import javax.naming.*;

public class Mysql {
    private Connection conn = null;
    private PreparedStatement ps = null;
    private Statement stm = null;

    // constructor 1
    public Mysql() throws Exception {
             
        conn=lookForConnection();
        if(conn!=null)
           stm = conn.createStatement();
        else
           System.out.println("get DB Connection Failure!");
    }

    // constructor 2
    public Mysql(String sql) throws Exception {
        conn=lookForConnection();  
         if(conn!=null)
         {   
             this.prepareStatement(sql);
             stm = conn.createStatement();
         }
         else
             System.out.println("get DB Connection Failure!");
    }
    
    private Connection lookForConnection()throws Exception
    {
        DataSource ds = null; 
         try{ 
             InitialContext ctx=new InitialContext(); 
             ds=(DataSource)ctx.lookup("java:comp/env/jdbc/mysql"); 
             Connection con= ds.getConnection();  
             return con;
         }
        catch(Exception ex){
             ex.printStackTrace();
             return null;
        } 
    }
    public void prepareStatement(String sql) throws SQLException {
        ps = conn.prepareStatement(sql);
    }

    public void clearParameters() throws SQLException {
        ps.clearParameters();
    }

    // return the connection object
    public Connection getConnection() {
        return conn;
    }

    // return the preparedstatement
    public PreparedStatement getPreparedStatement() {
        return ps;
    }

    // return the set of query
    public ResultSet executeQuery(String sql) throws SQLException {
        if (stm != null) {
            return stm.executeQuery(sql);
        } else
            return null;
    }

    // return the set of query
    public ResultSet executeQuery() throws SQLException {
        if (ps != null) {
            return ps.executeQuery();
        } else
            return null;
    }

    // execute the operation of update
    public void executeUpdate(String sql) throws SQLException {
        if (stm != null)
            stm.executeUpdate(sql);
        else
           System.out.println("the Statement is null");
    }

    // execute the operation of update
    public void executeUpdate() throws SQLException {
        if (ps != null)
        {
          ps.executeUpdate();
        }
        else
            System.out.println("the prepareStatement is null");   
    }

    // close the connection and free resource
    public void closeCon() throws SQLException {
        if (stm != null) {
            stm.close();
            stm = null;
        }
        if (ps != null) {
            ps.close();
            ps = null;
        }
        conn.close();
        conn = null;
    }

    // lock the table
    public boolean lockTable(String table, String privilege)throws SQLException {
        String locksql = "lock tables " + table + " " + privilege;
            if(this.executeQuery(locksql)!=null)
            {
                // System.out.println("lock");
                return true;
            }
            else
            return false;
    }

    // unlock the table
    public boolean unLockTable() throws SQLException{
        String unlocksql = "unlock tables ";
        if(this.executeQuery(unlocksql)!=null)
        {
            // System.out.println("unlock");
            return true;
        }
        else
            return false;
    }

    // set the parameter
    public void setString(int index, String value) throws SQLException {
        ps.setString(index, value);
    }

    public void setInt(int index, int value) throws SQLException {
        ps.setInt(index, value);
    }

    public void setBoolean(int index, boolean value) throws SQLException {
        ps.setBoolean(index, value);
    }

    public void setDate(int index, Date value) throws SQLException {
        ps.setDate(index, value);
    }

    public void setLong(int index, long value) throws SQLException {
        ps.setLong(index, value);
    }

    public void setFloat(int index, float value) throws SQLException {
        ps.setFloat(index, value);
    }
    public void setBinaryStream(int index,InputStream in,int length) throws SQLException {
        ps.setBinaryStream(index,in,length);
        }
}