spring入門：關鍵點整理（2）-- 註解

1：如果沒有用註解

1)目錄結構

2）spring及db配置文件

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


    <bean id="studentService" class="com.csdn.service.impl.StudentServiceImpl">
        <property name="studentDao" ref="studentDao"></property>
    </bean>

    <bean id="studentDao" class="com.csdn.dao.impl.StudentDaoImpl">
        <property name="queryRunner" ref="queryRunner"/>
    </bean>

    <bean id="queryRunner" class="org.apache.commons.dbutils.QueryRunner">
        <constructor-arg name="ds" ref="dataSource"/>
    </bean>

    <context:property-placeholder location="classpath*:db.properties"/>
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${db.driver}"/>
        <property name="jdbcUrl" value="${db.url}"/>
        <property name="user" value="${db.username}"/>
        <property name="password" value="${db.password}"/>
    </bean>

</beans>

db.perproties

db.driver = com.mysql.jdbc.Driver
db.url = jdbc:mysql:///student?useUnicode=true&characterEncoding=utf-8
db.username = root
db.password = 123456

3）部分源碼

StudentDaoImpl.java

package com.csdn.dao.impl;

import com.csdn.dao.StudentDao;
import com.csdn.pojo.Student;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

public class StudentDaoImpl implements StudentDao {

    private QueryRunner queryRunner;

    public void setQueryRunner(QueryRunner queryRunner) {
        this.queryRunner = queryRunner;
    }

    @Override
    public List<Student> queryList() throws SQLException {
        String sql = "select *  from student";
        return queryRunner.query(sql,new BeanListHandler<>(Student.class));
    }

}

StudentServiceImpl.java

package com.csdn.service.impl;

import com.csdn.dao.StudentDao;
import com.csdn.pojo.Student;
import com.csdn.service.StudentService;

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

public class StudentServiceImpl implements StudentService {
    StudentDao studentDao;

    public void setStudentDao(StudentDao studentDao) {
        this.studentDao = studentDao;
    }

    public List<Student> findAll() throws SQLException {
        return studentDao.queryList();
    }
}

Test.java 測試代碼

package com.csdn.test;

import com.csdn.pojo.Student;
import com.csdn.service.StudentService;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

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

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring.xml")
public class Test {
    @Autowired
    private StudentService studentService;

    @org.junit.Test
    public void test01(){
        List<Student> all = null;
        try {
            System.out.println(studentService);
            all = studentService.findAll();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        System.out.println(all);
    }
}

 

2：spring註解

1）將javabean放到spring容器中

@Repository 一般用於dao層

@Service 一般用於service層

@Controller 一般用於controller層

@Component 通用

2） 從spring容器中取出javabean對象

@Autowired 根據類型取

@Resource 根據名稱取

3）@Scope註解

@scope值爲singleton,prototype,request,session

4）@PostConstruct @Predestroy

5）註解示例

spring2.xml

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


    <!--掃描有註解的包-->
    <context:component-scan base-package="com.csdn.*"/>

    <bean id="queryRunner" class="org.apache.commons.dbutils.QueryRunner">
        <constructor-arg name="ds" ref="dataSource"/>
    </bean>

    <context:property-placeholder location="classpath*:db.properties"/>
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${db.driver}"/>
        <property name="jdbcUrl" value="${db.url}"/>
        <property name="user" value="${db.username}"/>
        <property name="password" value="${db.password}"/>
    </bean>


</beans>

StudentDaoImpl2.java  

package com.csdn.dao.impl;

import com.csdn.dao.StudentDao;
import com.csdn.pojo.Student;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

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

@Repository
public class StudentDaoImpl2 implements StudentDao {

    @Autowired
    private QueryRunner queryRunner;

    @Override
    public List<Student> queryList() throws SQLException {
        String sql = "select *  from student";
        return queryRunner.query(sql,new BeanListHandler<>(Student.class));
    }

}

StudentServiceImpl2.java 

package com.csdn.service.impl;

import com.csdn.dao.StudentDao;
import com.csdn.pojo.Student;
import com.csdn.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

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

@Service
public class StudentServiceImpl2 implements StudentService {
    @Autowired
    StudentDao studentDao2;

    public List<Student> findAll() throws SQLException {
        return studentDao2.queryList();
    }
}

Test.java  

package com.csdn.test;

import com.csdn.pojo.Student;
import com.csdn.service.StudentService;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

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

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring2.xml")
public class Test {
    @Autowired
    private StudentService studentService2;

    @org.junit.Test
    public void test01(){
        List<Student> all = null;
        try {
            System.out.println(studentService2);
            all = studentService2.findAll();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        System.out.println(all);
    }
}