java使用tomcat数据源连接mysql
主要是用tomcat提供的数据源 ，访问mysql数据库，进行sql查询、调用存储过程
写的很简单 用Servlet提供输出
import java.io.IOException;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.undergrowth.DataHandle;
/**
* Servlet implementation class MysqlTestServlet
*/
@WebServlet("/MysqlTestServlet")
public class MysqlTestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public MysqlTestServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/xml; charset=gbk");
response.setCharacterEncoding("utf-8");
try {
String whatString=DataHandle.transferXml("select * from grade");
//response.getWriter().write("MySql中文\n");
//System.out.println(whatString);
//用于调用存储过程使用
List params=new ArrayList();
params.add("好好学习");
String proce=DataHandle.callProcedure("test_proce", params);
System.out.println(proce);
//用于输出xml
response.getWriter().write(whatString);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
this.doGet(request, response);
}
}
数据处理类
package com.undergrowth;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.List;
public class DataHandle {
/*
* 将查询出来的结果转换为String
*/
public static String transfer(String sql) throws SQLException{
String result="没有结果";
ResultSet rs=ConnectData.getInstance().executeQuery(sql);
ResultSetMetaData resultSetMetaData=rs.getMetaData();
if(rs!=null){
result="";
while (rs.next()) {
for (int i = 0; i < resultSetMetaData.getColumnCount(); i++) {
result+=resultSetMetaData.getColumnName(i+1)+":"+rs.getString(i+1)+"\t";
}
result+="\n";
}
}
return result;
}
/**
* 将查询出来的结果转换为xml格式
* @param sql
* @return
* @throws SQLException
*/
public static String transferXml(String sql) throws SQLException{
String result="没有结果";
ResultSet rs=ConnectData.getInstance().executeQuery(sql);
ResultSetMetaData resultSetMetaData=rs.getMetaData();
if(rs!=null){
result="";
result+="";
while (rs.next()) {
result+="";
for (int i = 0; i < resultSetMetaData.getColumnCount(); i++) {
result+="<"+resultSetMetaData.getColumnName(i+1)+">"+rs.getString(i+1)+"";
}
result+=" ";
}
result+=" ";
}
return result;
}
/**
* 执行存储过程
* @param name
* @param params
* @return
*/
public static String callProcedure(String name,List params){
String resultString=ConnectData.getInstance().executeProce(name, params, true);
return resultString;
}
}
连接数据库
package com.undergrowth;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import java.util.Hashtable;
import java.util.List;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;
public class ConnectData {
/**
* 连接数据库的辅助类 单例模式构建
*
* @author undergrowth
*
*/
private DataSource dataSource;
private Connection conn;
private Statement stmt;
private ResultSet rs;
private PreparedStatement ps;
private CallableStatement cs;
private ConnectData() {
}
// 使用volatile关键字 保证在多个线程中获取oDbAssist无误
private volatile static ConnectData oDbAssist = null;
/**
* 双层锁
*
* @return
*/
public static ConnectData getInstance() {
if (oDbAssist == null) {
synchronized (ConnectData.class) {
if (oDbAssist == null) {
oDbAssist = new ConnectData();
oDbAssist.getDataSourceByJndi("test");
}
}
}
return oDbAssist;
}
public DataSource getDataSource() {
return dataSource;
}
public Connection getConn() {
return conn;
}
public void setConn(Connection conn) {
this.conn = conn;
}
public Statement getStmt() {
return stmt;
}
public void setStmt(Statement stmt) {
this.stmt = stmt;
}
public ResultSet getRs() {
return rs;
}
public void setRs(ResultSet rs) {
this.rs = rs;
}
/**
* 通过jndi从weblogic里面获取数据源
* jndi从tomcat里面获取数据源
*
* @return boolean flag 用于标示是否获取到数据源
*/
private boolean getDataSourceByJndi(String jndiDataSource) {
boolean flag = false;
String type = "tomcat";
if ("oracle".equals(type)) {
// 提供初始化jndi上下文的参数
Hashtable env = new Hashtable();
// 初始化工厂
env.put(Context.INITIAL_CONTEXT_FACTORY,
"weblogic.jndi.WLInitialContextFactory");
env.put(Context.PROVIDER_URL, "t3://localhost:7001");
try {
Context ctx = new InitialContext(env);
dataSource = (DataSource) ctx.lookup(jndiDataSource);
flag = true;
} catch (NamingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else if ("tomcat".equals(type)) {
try {
Context context = new InitialContext();
Context envContext = (Context) context.lookup("java:/comp/env");
dataSource = (DataSource) envContext.lookup(jndiDataSource);
flag = true;
} catch (NamingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return flag;
}
/**
* 获取数据连接
*
* @return
* @throws SQLException
*/
public Connection getConnection() throws SQLException {
if (getConn() == null)
conn = dataSource.getConnection();
return getConn();
}
/**
* 执行sql查询
*
* @param sql
* @return
* @throws SQLException
*/
public ResultSet executeQuery(String sql) throws SQLException {
stmt = getConnection().createStatement();
rs = stmt.executeQuery(sql);
return rs;
}
/**
*
* @param name
* 存储过程或者函数的名称
* @param param
* 参数列表
* @param flag
* 存储过程(1) 或者函数(0)
* @return
*/
public String executeProce(String name, List params, boolean flag) {
String result = "";
if (flag) { // 存储过程
String procedure = "{ call " + name;
String tempStr = "";
if (params != null && params.size() > 0) {
for (int i = 0; i <= params.size(); i++) {
if (i == 0)
tempStr = " ( ? ";
else
tempStr = tempStr + ", ?";
}
tempStr = tempStr + " ) ";
}
procedure = procedure + tempStr + " }";
try {
cs = getConnection().prepareCall(procedure);
cs.registerOutParameter(1, Types.VARCHAR);
setParamValue(cs, params);
cs.execute();
result = cs.getString(1);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else {// 函数
String procedure = "{ ?= call " + name;
String tempStr = "";
if (params != null && params.size() > 0) {
for (int i = 0; i < params.size(); i++) {
if (i == 0)
tempStr = " ( ? ";
else
tempStr = tempStr + ", ?";
}
tempStr = tempStr + " ) ";
}
procedure = procedure + tempStr + " }";
try {
cs = getConnection().prepareCall(procedure);
cs.registerOutParameter(1, Types.VARCHAR);
setParamValue(cs, params);
cs.execute();
result = cs.getString(1);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return result;
}
private void setParamValue(PreparedStatement theStmt, List params) {
for (int i = 0; i < params.size(); i++)
try {
theStmt.setObject(i + 2, params.get(i));
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
tomcat的context中添加