只要涉及到必须使用sql语句进行数据库操作的都可以用这个工具类，复用价值超级棒的有木有？
要进行操作时，只需要自己写一条sql语句，再调用JdbcUtil中的一个方法就好了，是不是超简洁？
//JdbcUtil.java
package xaut.wjh.util;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ParameterMetaData;
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 java.util.Properties;
import org.apache.commons.beanutils.BeanUtils;
/**
* 通用的jdbc工具类
*\获取连接\关闭连接\查询\更新
* @author 小花花
*
*/
public class JdbcUtil {
private static String url = null ;
private static String user = null ;
private static String password = null ;
private static String driverClass = null ;
static{
try{
Properties prop = new Properties() ;
InputStream in = JdbcUtil.class.getResourceAsStream("/jdbc.properties") ;
prop.load(in);
url = prop.getProperty("url") ;
user = prop.getProperty("user") ;
password = prop.getProperty("password") ;
driverClass = prop.getProperty("driverClass") ;
Class.forName(driverClass) ;
}catch(Exception e){
e.printStackTrace();
}
}
/**
* 建立连接
* @return
*/
public static Connection getConnection(){
try {
Connection conn = DriverManager.getConnection(url,user,password) ;
return conn ;
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e) ;
}
}
/**
* 判断是否有查询的数据
* @param sql
* @param values sql中对应的参数值
* @param clazz Bean对象的Class
* @return
*/
public static boolean query(String sql,Object[] values) {
Connection con=null;
PreparedStatement pstmt=null;
ResultSet rs=null;
try {
con=DriverManager.getConnection(url,user,password);
pstmt=con.prepareStatement(sql);
ParameterMetaData pmd = pstmt.getParameterMetaData();
int parameterCount=pmd.getParameterCount();
for(int i=1;i<=parameterCount;i++) {
pstmt.setObject(i,values[i-1]);
}
rs=pstmt.executeQuery();
if(rs.next()) {
return true;
}
else {
return false;
}
}
catch (Exception e) {
e.printStackTrace();
throw new RuntimeException();
}
finally {
JdbcUtil.close(pstmt, con, rs);;
}
}
/**
* 返回查询的结果
* @param sql
* @param values
* @param clazz
* @return
*/
public static<T> List<T> query(String sql,Object[] values,Class<T> clazz) {
Connection con=null;
PreparedStatement pstmt=null;
ResultSet rs=null;
try {
con=DriverManager.getConnection(url,user,password);
pstmt=con.prepareStatement(sql);
ParameterMetaData pmd = pstmt.getParameterMetaData();
int parameterCount=pmd.getParameterCount();
if(values!=null) {
for(int i=1;i<=parameterCount;i++) {
pstmt.setObject(i,values[i-1]);
}
}
rs=pstmt.executeQuery();
ResultSetMetaData rsmd = rs.getMetaData();
int count=rsmd.getColumnCount();
List li=new ArrayList();
while(rs.next()) {
Object obj=clazz.newInstance();
for(int i=1;i<=count;i++) {
Object value=rs.getObject(i);
BeanUtils.copyProperty(obj,rsmd.getColumnName(i),value);
}
li.add(obj);
}
return li;
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException();
}
finally {
JdbcUtil.close(pstmt, con, rs);;
}
}
/**
* 通用的Jdbc更新操作：插入\删除\修改
* @param sql
* @param values
*/
public static void update(String sql,Object[] values) {
Connection con=null;
PreparedStatement pStmt=null;
try {
con=DriverManager.getConnection(url,user,password);
pStmt = con.prepareStatement(sql);
ParameterMetaData pmd=pStmt.getParameterMetaData();
int count=pmd.getParameterCount();
for(int i=1;i<=count;i++) {
pStmt.setObject(i,values[i-1]);
}
pStmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException();
}
finally {
JdbcUtil.close(pStmt, con);
}
}
public static void close(Statement stmt,Connection con) {
if(stmt!=null) {
try {
stmt.close();
}
catch(SQLException e) {
e.printStackTrace();
}
finally {
if(con!=null) {
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
}
public static void close(PreparedStatement pstmt,Connection con,ResultSet rs){
if(pstmt!=null){
try {
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e) ;
}
finally{
if(con!=null){
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e) ;
}
finally {
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e) ;
}
}
}
}
}
}
}
}
另外还需要在src下建立一个jdbc.properties文件。如果需要连接不同的数据库只需要修改这个配置文件即可。
jdbc.properties
url=jdbc:mysql://localhost:3306/hibernate001?characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
user=root
password=root
driverClass=com.mysql.jdbc.Driver