代码如下：
/*JdbcTool.java*/
package com.qrsx.tools;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JdbcTool {
public static void main(String[] args) {
// TODO Auto-generated method stub
}
public static Connection getConn() {
Connection conn=null;
try {
//1加载驱动
Class.forName("com.mysql.jdbc.Driver");
String url="jdbc:mysql://localhost:3306/mydb?charcterEncoding=UTF-8";
String user="root";
String password="123";
//获取连接
conn=DriverManager.getConnection(url,user,password);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return conn;
}
public static void Close(ResultSet rs,PreparedStatement ps,Connection conn){
try {
if(rs!=null){
rs.close();}
if(ps!=null){
ps.close();}
if(conn!=null){
conn.close(); }
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static int exec_update(String sql,Object...para){
int i=0;
try {
Connection conn=JdbcTool.getConn();
PreparedStatement ps=conn.prepareStatement(sql);
System.out.println(para.length);
for(int j=0;j<para.length;j++){
ps.setObject(j+1, para[j]);
}
i=ps.executeUpdate();
System.out.println(i+"行受到影响!");
JdbcTool.Close(null, ps, conn);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return i;
}
}
/*testDb*/
package com.qrsx.shop;
import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.qrsx.tools.JdbcTool;
public class testDb {
public static void main(String[] args) {
Connection conn=JdbcTool.getConn();
String sql="select *from good";
try {
PreparedStatement ps=conn.prepareStatement(sql);
ResultSet rs=ps.executeQuery();
while(rs.next()){
System.out.print(rs.getInt(1));
System.out.print(rs.getString(2));
System.out.print(new BigDecimal(rs.getString(3)));
System.out.println(rs.getInt(4));
}
JdbcTool.Close(rs, ps, conn);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
<*多重?号查询*>
public static void main(String[] args) {
JdbcTest jd=new JdbcTest();
//jd.simpleQuery();
//jd.simpleQueryByName2("java","6");
//jd.delete(3);
String sql="delete from user where id=?";
int i=JdbcTool.exec_update(sql, 7);
jd.simpleQuery();
sql="insert into user(username,password)values(?,?)";
i=JdbcTool.exec_update(sql, "张三","zhangsan");
}