spring示例--01

主要内容：bean的装配

①完全的基于xml配置

②基于配置类的

③去掉xml，完全靠注解的

1. 准备工作

1.1 数据准备：

CREATE TABLE `user` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) NOT NULL,
  `birthday` datetime DEFAULT NULL,
  `sex` varchar(10) DEFAULT NULL,
  `address` varchar(40) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8

INSERT INTO test.user (id, name, birthday, sex, address) VALUES (1, 'name1', '1995-01-01 00:00:00', 'man', 'address1');
INSERT INTO test.user (id, name, birthday, sex, address) VALUES (2, 'name2', '1995-01-01 00:00:00', 'man', 'address2');

1.2 数据操作：使用JdbcTemplate，暂忽略事务控制

1.3 maven包：全都是4.0.0版本

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
  <version>${spring-context.version}</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-core</artifactId>
  <version>${spring-core.version}</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-beans</artifactId>
  <version>${spring-beans.version}</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-expression</artifactId>
  <version>${spring-expression.version}</version>
</dependency>
<!--spring aop-->
<!--    <dependency>-->
<!--      <groupId>org.springframework</groupId>-->
<!--      <artifactId>spring-aop</artifactId>-->
<!--      <version>${spring-aop.version}</version>-->
<!--    </dependency>-->
<!--spring jdbc-->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-jdbc</artifactId>
  <version>${spring-jdbc.version}</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-tx</artifactId>
  <version>${spring-tx.version}</version>
</dependency>

1.4 实体类

package xt.domain;

import lombok.*;


@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class User {
    private Integer id;
    private String username;
    private String birthday;
    private String sex;
    private String address;

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", birthday=" + birthday +
                ", sex='" + sex + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

2. 基于xml的

Dao里面通过JdbcTemplate执行sql，JdbcTemplate通过xml配置装配（构造函数注入）到Dao上

package xt.demo.dao;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.PreparedStatementSetter;
import org.springframework.jdbc.core.RowMapper;
import xt.domain.User;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.sqlException;
import java.util.List;

public class UserDao {
    private JdbcTemplate jt;  
    public UserDao(JdbcTemplate jt) {this.jt = jt;}
    
    public int saveUser(User user) {
        return jt.update("insert into user values(null,?,?,?,?)",new PreparedStatementSetter(){
            @Override
            public void setValues(PreparedStatement ps) throws sqlException {
                ps.setString(1,user.getUsername());
                ps.setString(2,user.getBirthday());
                ps.setString(3,user.getSex());
                ps.setString(4,user.getAddress());
            }
        });
    }

    public List<User> queryAllUser() {
        List<User> lists = jt.query("select * from user", new RowMapper<User>() {
            @Override
            public User mapRow(ResultSet resultSet, int i) throws sqlException {
                User user = new User();
                user.setId(resultSet.getInt("id"));
                user.setUsername(resultSet.getString("name"));
                user.setBirthday(resultSet.getString("birthday"));
                user.setSex(resultSet.getString("sex"));
                user.setAddress(resultSet.getString("address"));
                return user;
            }
        });
        return lists;
    }
}

相应的配置文件：beanx.xml 放在Resources的一级目录下

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean id="UserDao" class="xt.demo.dao.UserDao">
        <constructor-arg name="jt" ref="jdbcTemplate"/>
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource1"></property>
    </bean>

    <!--数据源-->
    <bean id="dataSource1" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.MysqL.jdbc.Driver" />
        <property name="url" value="jdbc:MysqL://127.0.0.1:3306/test?serverTimezone=UTC&amp;useUnicode=true&amp;characterEncoding=utf8"/>    <!--注意&符号写为 &amp;  否则解析配置文件会出错-->
        <property name="username" value="root"/>
        <property name="password" value="123"/>
    </bean>
</beans>

测试：

ApplicationContext ac = new ClasspathXmlApplicationContext("beans.xml");
UserDao userDao = ac.getBean("UserDao", UserDao.class);
List<User> users = userDao.queryAllUser();

基于xml装配特点：

自由使用，比如自己写的Dao里面，要用到第三方库里的JdbcTemplate，在bean标签里面引用即可

对象很多时，bean标签也多了起来；每个要获取bean里面的对象的地方，都要先读取xml返回ApplicationContext对象

3. 基于配置类

配置类与业务逻辑无关，单独放在一个地方，只用来配置bean（通过java配置类装配而不是xml里的bean标签）

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