【Java】JDBC Part6 DBUtils工具依赖 -云博客

【Java】JDBC Part6 DBUtils工具依赖

# 数据库 2024-05-05 12:47 0 28 来源：云博客

Apache-DBUtils

开源的JDBC工具类，对JDBC的简单封装

SQL操作交给了QueryRunner的实例

Maven依赖

<!-- https://mvnrepository.com/artifact/commons-dbutils/commons-dbutils --><dependency> <groupId>commons-dbutils</groupId> <artifactId>commons-dbutils</artifactId> <version>1.7</version></dependency>

插入语句测试【删改同理操作】

 @Test public void dbTest() throws SQLException { QueryRunner queryRunner = new QueryRunner(); Connection connectionByOriginalJdbc = CompleteJdbcUtils.getConnectionByOriginalJdbc(); String sql = "insert into user(user_name,user_password,user_createTime) values(?,?,?);"; int update = queryRunner.update(connectionByOriginalJdbc, sql, "你弟含王", "121314",CompleteJdbcUtils.parseToSqlDate("1997-09-06")); System.out.println(update); CompleteJdbcUtils.releaseResource(connectionByOriginalJdbc,null,null); }

查询单个的QueryRunner

- BeanHandler<T>

 @Test public void dbTest2() throws SQLException { QueryRunner queryRunner = new QueryRunner(); Connection connectionByOriginalJdbc = CompleteJdbcUtils.getConnectionByHikari(); // 实体类处理器对象 BeanHandler<User> beanHandler = new BeanHandler<User>(User.class); String sql = "select * from user where user_id = ?;"; // 根据BeanHandler反射过去 只能处理单个对象返回 User query = queryRunner.query(connectionByOriginalJdbc, sql, beanHandler,3); System.out.println(query); CompleteJdbcUtils.releaseResource(connectionByOriginalJdbc,null,null); }

用Map封装单个记录的 MapHandler,默认泛型<String,Object>

 @Test public void dbTest21() throws SQLException { QueryRunner queryRunner = new QueryRunner(); Connection connectionByOriginalJdbc = CompleteJdbcUtils.getConnectionByHikari(); // 实体类处理器对象 MapHandler mapHandler = new MapHandler(); // <String,Object> String sql = "select * from user where user_id = ?;"; // 根据BeanHandler反射过去 只能处理单个对象返回 Map<String, Object> map = queryRunner.query(connectionByOriginalJdbc, sql, mapHandler, 3); System.out.println(map); CompleteJdbcUtils.releaseResource(connectionByOriginalJdbc,null,null); }

多个记录的BeanListHandler<T>处理

 @Test public void dbTest3() throws SQLException { QueryRunner queryRunner = new QueryRunner(); Connection connectionByOriginalJdbc = CompleteJdbcUtils.getConnectionByHikari(); // 实体类处理器对象 BeanListHandler<User> beanHandler = new BeanListHandler<User>(User.class); String sql = "select * from user;"; // 根据BeanHandler反射过去 返回List集合封装的对象的处理 List<User> users = queryRunner.query(connectionByOriginalJdbc, sql, beanHandler); for (User user:users) { System.out.println(user); } CompleteJdbcUtils.releaseResource(connectionByOriginalJdbc,null,null); }

或者是MapListHandler,泛型是<String,Object>

 @Test public void dbTest31() throws SQLException { QueryRunner queryRunner = new QueryRunner(); Connection connectionByOriginalJdbc = CompleteJdbcUtils.getConnectionByHikari(); // 实体类处理器对象 MapListHandler mapListHandler = new MapListHandler(); String sql = "select * from user;"; List<Map<String, Object>> maps = queryRunner.query(connectionByOriginalJdbc, sql, mapListHandler); for (Map map:maps) { System.out.println(map); } CompleteJdbcUtils.releaseResource(connectionByOriginalJdbc,null,null); }