java中JDBC基本操作的一个工具类,一些基本方法

package com.help;

import java.io.UnsupportedEncodingException;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.ArrayList;

import java.util.List;

import com.microsoft.sqlserver.jdbc.SQLServerDataSource;

import com.microsoft.sqlserver.jdbc.SQLServerException;

public final class Dbutils {

//1005和1008常量字段

public static final int TYPE=ResultSet.TYPE_SCROLL_SENSITIVE;

public static final int UPDATE=ResultSet.CONCUR_UPDATABLE;

private Dbutils(){}

//传入参数获取sql2005数据库连接的方法

public static Connection getConnection(String server,

String db,String user,String password){

SQLServerDataSource sds=new SQLServerDataSource();

sds.setServerName(server);

sds.setDatabaseName(db);

sds.setUser(user);

sds.setPassword(password);

Connection connection=null;

try {

connection=sds.getConnection();

} catch (SQLServerException e) {

e.printStackTrace();

}

return connection;

}

public static Connection getConnection(String db){

SQLServerDataSource sds=new SQLServerDataSource();

sds.setServerName("localhost");

sds.setDatabaseName(db);

sds.setUser("sa");

sds.setPassword("123456");

Connection connection=null;

try {

connection=sds.getConnection();

} catch (SQLServerException e) {

e.printStackTrace();

}

return connection;

}

//关闭数据库资源的方法,对此方法重载关闭多种数据库资源

public static void close(Connection conn){

if(conn!=null){

try {

conn.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

public static void close(Statement stmt){

if(stmt!=null){

try {

stmt.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

public static void close(ResultSet rs){

if(rs!=null){

try {

rs.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

//传入标准sql查询语句和Connection返回一个ResultSet(结果集),此SQL只能进行查询不能修改表

public static ResultSet getResultSet(String sql,Connection connection){

Statement stmt=null;

ResultSet rst=null;

try {

stmt=connection.createStatement(Dbutils.TYPE, Dbutils.UPDATE);

rst=stmt.executeQuery(sql);

} catch (SQLException e) {

e.printStackTrace();

}

return rst;

}

//传入sql语句,可以对表进行增删改查

public static void Update(String sql,Connection connection){

Statement stmt=null;

int a=0;

try {

stmt=connection.createStatement(Dbutils.TYPE,Dbutils.UPDATE);

a=stmt.executeUpdate(sql);

} catch (SQLException e) {

MyUnit.showMessage(e.getMessage());

}if(a>0){

System.out.println("更新成功");

}

}

//遍历结果集返回一个字符串

public static String getString(ResultSet rs){

ResultSetMetaData rsmt=null;

try {

rsmt=rs.getMetaData();

int a=rsmt.getColumnCount();

while(rs.next()){

for (int i = 1; i <= a; i++) {

if(i!=1){

System.out.print(",");

}

System.out.print(rs.getObject(i));

}

System.out.println();

}

} catch (SQLException e) {

e.printStackTrace();

}

return null;

}

//返回一个表结果集行数的方法

public static int getRowCount(Connection connection,String tname){

ResultSet rs=getResultSet("select count(*) from "+"["+tname+"]", connection);

int page=0;

try {

while(rs.next()){

page=(Integer)rs.getObject(1);

}

} catch (SQLException e) {

e.printStackTrace();

}

return page;

}

//返回一个分页页数

public static int getPages(Connection connection,String tname,int pagesize){

if(connection==null||tname==null||pagesize<=0){

return 0;

}

int rows=getRowCount(connection, tname);

int pageSize=rows%pagesize==0?rows/pagesize:rows/pagesize+1;

return pageSize;

}

//获得一个带有列名的list

public static List<String> getColumnName(Connection connection,String tname){

PreparedStatement pstmt=null;

ResultSet rs=null;

List<String> ls=new ArrayList<String>();

try {

pstmt=connection.prepareStatement("select* from "+tname +" where 1<>1",Dbutils.TYPE,Dbutils.UPDATE);

rs=pstmt.executeQuery();

ResultSetMetaData rsmd=rs.getMetaData();

int column=rsmd.getColumnCount();

for (int i = 1; i <=column; i++) {

ls.add(rsmd.getColumnName(i));

}

} catch (SQLException e) {

e.printStackTrace();

}finally{

Dbutils.close(rs);

Dbutils.close(pstmt);

}

return ls;

}

//Jsp和servlet中get请求处理中文乱码的方法

public static String getNewString(String str) throws UnsupportedEncodingException{

return new String(str.getBytes("ISO-8859-1"),"UTF-8");

}

//传入3个参数:Connection,pageSize分页数,tableName,用分页方法返回一个List集合,其中每个元素都是一个结果集

public static String SelectPage(Connection connection,int pageSize,String columnname,String tablename){

//构造分页查询的标准SQL语句,其中row_number() over(order by 列名)函数返回一个自增的自然数列,

//按条件:rowid between ? and ?对表进行分页,其中?为每次分页的起始和结束

String sql="select * from (select row_number() over(order by "+

columnname+") rowid, * from "+tablename+") as temp where rowid between ? and ?";

PreparedStatement pstmt=null;

int rows = Dbutils.getRowCount(connection, tablename);//调用获得行数的方法

//分页的页数:如果可以被行数整除,商就是分页数,不能整除(商+1)就是分页数

int pages = rows % pageSize == 0 ? rows / pageSize : rows/pageSize + 1;

ResultSet rs=null;

String str=null;

try {

pstmt=connection.prepareStatement(sql,Dbutils.TYPE,Dbutils.UPDATE);

for (int i = 1; i <=pages ; i++) {

int start=1+(i-1)*pageSize;

int end=start+pageSize-1;

pstmt.setInt(1, start);

pstmt.setInt(2, end);

rs=pstmt.executeQuery();

str=Dbutils.getString(rs);

}

} catch (SQLException e) {

e.printStackTrace();

}

return str;

}

}