写一个简单得到Connection对象的工具类
package com.yds;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import org.apache.commons.dbutils.DbUtils;
/**
* 得到connection对象
* @author yu
*
*/
public class GetConnection {
private static GetConnection connection;
private GetConnection(){
}
public static GetConnection getInstants(){
if(connection==null){
connection=new GetConnection();
}
return connection;
}
/**
* 得到connection对象
* @return
*/
public Connection getConn(){
Connection conn=null;
boolean flag=DbUtils.loadDriver("com.mysql.jdbc.Driver");
if(flag){
try {
conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "1234");
} catch (SQLException e) {
}
}
return conn;
}
}
实现DBUtils查询所有
package com.yds;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.MapListHandler;
/**
* 查询所有
* @author yu
*
*/
public class QueryAll {
public static void main(String[] args) {
GetConnection getConnection=GetConnection.getInstants();
Connection conn=getConnection.getConn();
//创建查询器
QueryRunner query=new QueryRunner();
try {
List list=(List)query.query(conn,"select * from t_user", new MapListHandler());
for(Object obj:list){
Map map=(Map)obj;
System.out.println(map.get("id"));
}
} catch (SQLException e) {
e.printStackTrace();
}finally {
try {
DbUtils.close(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
增加
package com.yds;
import java.sql.Connection;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.ScalarHandler;
/**
* 增删改操作
* insert和update的区别
* insert插入进去的值,返回插入的主键id
* update执行后,返回影响后的条数
* @author yu
*
*/
public class Cud {
public static void main(String[] args) {
GetConnection getConnection=GetConnection.getInstants();
Connection conn=getConnection.getConn();
create(conn);
}
public static void create(Connection conn){
QueryRunner qr=new QueryRunner();
StringBuffer sql=new StringBuffer();
sql.append("insert into t_user(userName,passWord) values(");
sql.append("'测试用户名'");
sql.append(",");
sql.append("'测试密码'");
sql.append(")");
try {
//qr.update(conn, sql.toString(), null);
Long pk=qr.insert(conn, sql.toString(),new ScalarHandler<Long>());
System.out.println(pk);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
返回对象封装、代码和jar在附件中。
转载于:https://blog.51cto.com/ityds/1795967