java-jdbc工具类（QueryRunner）

来源：互联网发布：正版cad2017软件多少钱编辑：程序博客网时间：2024/05/18 03:24

为了快捷开发，避免代码重复量，使用JDBC工具类
需要两个jar包，一个文件

package com.west.jdbcutil;import java.io.IOException;import java.io.InputStream;import java.sql.Connection;import java.sql.DriverManager;import java.util.Properties;public class JDBCUtilsConfig {    private static Connection con;    private static String driverClass;    private static String url;    private static String username;    private static String password;    static {        try {            readConfig();            Class.forName(driverClass);            con=DriverManager.getConnection(url, username, password);        } catch (Exception e) {            throw new RuntimeException("数据库连接失败");        }    }    private static void readConfig() throws IOException {        InputStream in=JDBCUtilsConfig.class.getClassLoader().getResourceAsStream("base.properties");        Properties pro = new Properties();        pro.load(in);        driverClass=pro.getProperty("driverClass");        url=pro.getProperty("url");        username=pro.getProperty("username");        password=pro.getProperty("password");    }    public static Connection getConnection() {        return con;    }}

package com.west.demo;import java.sql.Connection;import java.sql.SQLException;import org.apache.commons.dbutils.DbUtils;import org.apache.commons.dbutils.QueryRunner;import com.west.jdbcutil.JDBCUtilsConfig;/* * 使用QueryRunner类，实现对数据表的操作 * insert delete update * 调用QueryRunner类的方法update(Connection con,String sql,Object param) * Object param 可变参数，Object类型，SQL语句会出现？占位符 * 数据库连接对象，自定义工具类 */public class QueryRunnerDemo {    private static Connection con=JDBCUtilsConfig.getConnection();    public static void main(String[] args) throws Exception {         //delete();        // update();         insert();    }    /*     * 定义方法，使用QueryRunner类的方法delete将表数据删除     *      */    public static void delete() throws Exception {    //创建QueryRunner类对象        QueryRunner qr=new QueryRunner();        String sql="DELETE FROM sort WHERE sid=?";        //调用QueryRunner方法update        int row=qr.update(con, sql,2);        System.out.println(row);        /*         *  判断insert,update,delete执行是否成功         *  对返回值row判断         *  if(row>0) 执行成功         */        DbUtils.closeQuietly(con);    }    /*     * 定义方法，使用QueryRunner类的方法update将表数据修改     *      */    public static void update() throws Exception {        QueryRunner qr=new QueryRunner();        String sql="UPDATE sort SET sname=?,sprice=?,sdesc=? WHERE sid=?";        Object[] params= {"花卉",100.88,"情人节玫瑰花",4};        int row=qr.update(con, sql, params);        System.out.println(row);        DbUtils.closeQuietly(con);    }    /*     * 定义方法，使用QueryRunner类的方法update向表中添加数据     *     */    public static void insert() throws SQLException {        QueryRunner qr=new QueryRunner();        String sql="INSERT INTO sort (sid,sname,sprice,sdesc) VALUES (?,?,?,?)";        Object[] params= {8,"鼠标",123,"玩游戏"};        int row = qr.update(con, sql, params);        System.out.println(row);        DbUtils.closeQuietly(con);    }}

QueryRunner实现数据库查询操作：

package com.west.demo;public class Sort {    private int sid;    private String sname;    private double sprice;    private String sdesc;    public Sort(int sid, String sname, double sprice, String sdesc) {        this.sid = sid;        this.sname = sname;        this.sprice = sprice;        this.sdesc = sdesc;    }    public Sort(){}    public int getSid() {        return sid;    }    public void setSid(int sid) {        this.sid = sid;    }    public String getSname() {        return sname;    }    public void setSname(String sname) {        this.sname = sname;    }    public double getSprice() {        return sprice;    }    public void setSprice(double sprice) {        this.sprice = sprice;    }    public String getSdesc() {        return sdesc;    }    public void setSdesc(String sdesc) {        this.sdesc = sdesc;    }    @Override    public String toString() {        return "Sort [sid=" + sid + ", sname=" + sname + ", sprice=" + sprice + ", sdesc=" + sdesc + "]";    }}

package com.west.demo;import java.sql.Connection;import java.sql.SQLException;import java.util.List;import java.util.Map;import org.apache.commons.dbutils.QueryRunner;import org.apache.commons.dbutils.handlers.ArrayHandler;import org.apache.commons.dbutils.handlers.ArrayListHandler;import org.apache.commons.dbutils.handlers.BeanHandler;import org.apache.commons.dbutils.handlers.BeanListHandler;import org.apache.commons.dbutils.handlers.ColumnListHandler;import org.apache.commons.dbutils.handlers.MapHandler;import org.apache.commons.dbutils.handlers.MapListHandler;import org.apache.commons.dbutils.handlers.ScalarHandler;import com.west.jdbcutil.JDBCUtilsConfig;/* * QueryRunner数据库查询操作 * 调用QueryRunner类方法query(Connection con,String sql,ResultSetHandler r,Object..params) * ResultSetHandle r结果集的处理方式，传递ResultSetHandler接口实现类 * Object...params SQl语句中的占位符 * 注意：query 方法返回值，返回的是T泛型 */public class QueryRunnerDemo1 {    private static Connection con =JDBCUtilsConfig.getConnection();    public static void main(String[] args) throws SQLException {        //arrayHandle();//      arrayListHandler();        //beanHandler();        //beanListHander();//      columnListHandler();//      scalarHandler();        mapListHandler();    }    /*     *  结果集第八种处理方法,MapListHandler     *  将结果集每一行存储到Map集合,键:列名,值:数据     *  Map集合过多,存储到List集合     */    public static void mapListHandler()throws SQLException{        QueryRunner qr = new QueryRunner();        String sql = "SELECT  * FROM sort";        //调用方法query,传递结果集实现类MapListHandler        //返回值List集合, 存储的是Map集合        List<Map<String,Object>> list = qr.query(con, sql, new MapListHandler());        //遍历集合list        for( Map<String,Object> map : list ){            for(String key : map.keySet()){                System.out.print(key+"..."+map.get(key));            }            System.out.println();        }    }    /*     *  结果集第七种处理方法,MapHandler     *  将结果集第一行数据,封装到Map集合中     *  Map<键,值> 键:列名  值:这列的数据     */    public static void mapHandler()throws SQLException{        QueryRunner qr = new QueryRunner();        String sql = "SELECT  * FROM sort";        //调用方法query,传递结果集实现类MapHandler        //返回值: Map集合,Map接口实现类, 泛型        Map<String,Object> map = qr.query(con, sql, new MapHandler());        //遍历Map集合        for(String key : map.keySet()){            System.out.println(key+".."+map.get(key));        }    }    /*     *  结果集第六种处理方法,ScalarHandler     *  对于查询后,只有1个结果     */    public static void scalarHandler() throws SQLException {        QueryRunner qr=new QueryRunner();        String sql="select count(*) from sort";        long count =qr.query(con,sql,new ScalarHandler<Long>());        System.out.println(count);    }    /*     *  结果集第五种处理方法,ColumnListHandler     *  结果集,指定列的数据,存储到List集合     *  List<Object> 每个列数据类型不同     */    public static void columnListHandler()throws SQLException{        QueryRunner qr = new QueryRunner();        String sql = "SELECT * FROM sort ";             //调用方法 query,传递结果集实现类ColumnListHandler        //实现类构造方法中,使用字符串的列名        List<Object> list = qr.query(con, sql, new ColumnListHandler<Object>("sprice"));        for(Object obj : list){            System.out.println(obj);        }    }    /*     *  结果集第四种处理方法, BeanListHandler     *  结果集每一行数据,封装JavaBean对象     *  多个JavaBean对象,存储到List集合     */    public static void beanListHander()throws SQLException{        QueryRunner qr = new QueryRunner();        String sql = "SELECT * FROM sort ";        //调用方法query,传递结果集处理实现类BeanListHandler        List<Sort> list = qr.query(con, sql, new BeanListHandler<Sort>(Sort.class));        for(Sort s : list){            System.out.println(s);        }    }    /*     * 结果集第三种处理方法，BeanHandler     * 将结果集的第一行数据，封装成javaBean对象     * 注意: 被封装成数据到JavaBean对象, Sort类必须有空参数构造     *      */    public static void beanHandler()throws SQLException{        QueryRunner qr = new QueryRunner();        String sql = "SELECT * FROM sort ";        //调用方法,传递结果集实现类BeanHandler        //BeanHandler(Class<T> type)        Sort s=qr.query(con, sql,new BeanHandler<Sort>(Sort.class));        System.out.println(s);    }    /*     *  结果集第二种处理方法,ArrayListHandler     *  将结果集的每一行,封装到对象数组中, 出现很多对象数组     *  对象数组存储到List集合     */    public static void arrayListHandler() throws SQLException {        QueryRunner qr=new QueryRunner();        String sql = "SELECT * FROM sort";        List<Object[]> result=qr.query(con, sql,new ArrayListHandler());        //集合的遍历        for(Object[] obj:result) {            //遍历对象数组            for(Object objs : obj){                System.out.print(objs+"  ");            }            System.out.println();        }    }    /*     * 结果集的第一种处理方式，ArrayHandler     * 将结果集的第一行存储到对象数组中 Object[]     *      */    public static void arrayHandle() throws SQLException {        QueryRunner qr=new QueryRunner();        String sql="SELECT * FROM sort";        Object[] result=qr.query(con,sql,new ArrayHandler());        for(Object objs:result) {            System.out.println(objs);        }    }}

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