DBUtils学习一 增删该查

 package com.mozq.jdbc.test;

 import java.sql.SQLException;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;

 import org.apache.commons.dbutils.QueryRunner;
 import org.apache.commons.dbutils.handlers.BeanHandler;
 import org.apache.commons.dbutils.handlers.BeanListHandler;
 import org.apache.commons.dbutils.handlers.BeanMapHandler;
 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 org.junit.Test;

 import com.mozq.domain.User;
 import com.mozq.jdbc.C3P0Utils;

 public class DBUtilsTest_R {
     /**
      * 测试查询用户数量,ScalarHandler处理器，new ScalarHandler<Long>(),注意类型参数只能写Long，不能写Integer
      */
     @Test
     public void findAll_ScalarHandler() {
         try {
             //1.创建核心执行对象
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             //2.写sql
             String sql = "select count(*) from t_user";
             //3.准备参数
             //4.执行sql，进行结果处理
              Long row = queryRunner.query(sql, new ScalarHandler<Long>());
              System.out.println("操作行数：" + row);
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
     /**
      * 测试根查询所有用户,MapListHandler处理器，new MapListHandler()
      */
     @Test
     public void findAll_MapListHandler() {
         try {
             //1.创建核心执行对象
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             //2.写sql
             String sql = "select * from t_user";
             //3.准备参数
             //4.执行sql，进行结果处理
             List<Map<String, Object>> users = queryRunner.query(sql, new MapListHandler());
             for(Map<String, Object> user : users) {
                 for(Entry<String, Object> entry : user.entrySet()) {
                     System.out.print(entry.getKey()+":"+entry.getValue()+";");
                 }
                 System.out.println();
             }
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
     /**
      * 测试根据id查询单个用户,MapHander处理器，new MapHandler()
      */
     @Test
     public void findById_MapHandler() {
         try {
             //1.创建核心执行对象
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             //2.写sql
             String sql = "select * from t_user where id=?";
             //3.准备参数
             Object[] params = {9};
             //4.执行sql，进行结果处理
             Map<String, Object> user = queryRunner.query(sql, new MapHandler(), params);
             for (Entry<String, Object> entry : user.entrySet()) {
                 System.out.println(entry.getKey()+ ":" + entry.getValue());
             }
             /*
                 id:9
                 name:刘备
                 password:liu456
              */
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
     /**
      * 测试查询全部用户名,ColumnList处理器，按列索引处理(需要在查询语句中明确列顺序)和按列名处理
      */
     @Test
     public void findAllName_ColumnListHandler() {
         try {
             //1.创建核心执行对象
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             //2.写sql
             String sql = "select password, name, id from t_user";
             //3.准备参数
             //4.执行sql，进行结果处理
             List<String> userNames = queryRunner.query(sql,  new ColumnListHandler<String>());
             for (String userName : userNames) {
                 System.out.println(userName);
             }
             List<String> userNames2 = queryRunner.query(sql,  new ColumnListHandler<String>("name"));
             for (String userName : userNames2) {
                 System.out.println(userName);
             }

         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
     /**
      * 测试查询全部,BeanMap处理器，new BeanMapHandler<Integer, User>(User.class, "id")
      */
     @Test
     public void findAll_BeanMapHandler() {
         try {
             //1.创建核心执行对象
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             //2.写sql
             String sql = "select id, name, password from t_user";
             //3.准备参数
             //4.执行sql，进行结果处理
             /*用主键列来当键，完全没有问题*/
             System.out.println("new BeanMapHandler<Integer, User>(User.class, \"id\")");
             Map<Integer, User> users = queryRunner.query(sql,  new BeanMapHandler<Integer, User>(User.class, "id"));
             for (Entry<Integer, User> it : users.entrySet()) {
                 System.out.println(it.getValue());
             }

             /*用可重复的列来当键，会发生记录覆盖*/
             System.out.println("new BeanMapHandler<String, User>(User.class, \"name\")----------");
             Map<String, User> users2 = queryRunner.query(sql,  new BeanMapHandler<String, User>(User.class, "name"));
             for (Entry<String, User> it : users2.entrySet()) {
                 System.out.println(it.getValue());
             }

         } catch (SQLException e) {
             e.printStackTrace();
             //java.sql.SQLException: Cannot determine value type from string 'liu123' Query: select * from t_user Parameters: []
         }
     }
     /**
      * 测试查询全部,BeanList处理器，new BeanListHandler<User>(User.class)
      */
     @Test
     public void findAll_BeanListHandler() {
         try {
             //1.创建核心执行对象
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             //2.写sql
             String sql = "select * from t_user";
             //3.准备参数
             //4.执行sql，进行结果处理
             List<User> users = queryRunner.query(sql,  new BeanListHandler<User>(User.class));
             for (User user : users) {
                 System.out.println(user);
             }
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
     /**
      * 测试根据id查询单个,Bean处理器，new BeanHandler<User>(User.class)
      */
     @Test
     public void findById_BeanHandler() {
         try {
             //1.创建核心执行对象
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             //2.写sql
             String sql = "select * from t_user where id=?";
             //3.准备参数
             Object[] params = {9};
             //4.执行sql，进行结果处理
             User user = queryRunner.query(sql,  new BeanHandler<User>(User.class), params);
             System.out.println(user);//User [id=9, name=刘备, password=liu123]
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
 }

 package com.mozq.jdbc.test;

 import java.sql.SQLException;

 import org.apache.commons.dbutils.QueryRunner;
 import org.apache.commons.dbutils.handlers.BeanHandler;
 import org.junit.Test;

 import com.mozq.domain.User;
 import com.mozq.jdbc.C3P0Utils;

 /**
  * 测试DBUtils工具类的增删改操作
  * @author jie
  *
  */
 public class DBUtilsTest_CUD {
     /**
      * 根据id删除用户
      */
     @Test
     public void DeleteUserById() {
         try {
             // 1.创建核心类
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             // 2.写sql
             String sql = "delete from t_user where id=?";
             // 3.准备参数
             Object[] params = { 8 };
             // 4.执行sql，进行结果处理
             int row = queryRunner.update(sql, params);
             if (row > 0) {
                 System.out.println("删除成功");
             } else {
                 System.out.println("删除失败");
             }
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }

     /**
      * 根据id修改用户
      */
     @Test
     public void UpdateUserById() {
         try {
             // 1.创建核心类
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             // 2.写sql
             String sql = "update t_user set password=? where id=?";
             // 3.准备参数
             Object[] params = { "jingdong", 8 };
             int row = queryRunner.update(sql, params);
             if (row > 0) {
                 System.out.println("修改成功");
             } else {
                 System.out.println("修改失败");
             }
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }

     /**
      * 插入用户方法
      */
     @Test
     public void addUser() {
         try {
             // 1.创建核心类
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             // 2.写sql
             String sql = "insert into t_user(name, password) values(?,?)";
             // 3.准备参数
             Object[] params = { "京东0", "刘强东0" };
             int row = queryRunner.update(sql, params);
             if (row > 0) {
                 System.out.println("插入成功");
             } else {
                 System.out.println("插入失败");
             }
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }

     /**
      * 测试insert方法，查看返回对象
      */
     @Test
     public void insert2() {
         try {
             QueryRunner queryRunner = new QueryRunner(C3P0Utils.getDataSource());
             String sql = "insert into t_user(id, name, password) values(?, ?, ?)";
             User userObj = queryRunner.insert(sql, new BeanHandler<User>(User.class), 31, "京东5", "刘强东");
             System.out.println(userObj);
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
 }