• Spring dbcp连接池配置与示例(以及JDBCTemplate的使用)


    Apache的DBCP

    首先要导入的jar包:

    dbpc需要的包:

    除了Spring核心包之外的jar包:

    我们要做的示例:(利用dbcp连接池实现对t_student表的增删改查)

    废话不多少,上xml配置

    <?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:aop="http://www.springframework.org/schema/aop"
        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/aop 
            http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
            http://www.springframework.org/schema/context 
            http://www.springframework.org/schema/context/spring-context-4.3.xsd">
        
        <!-- 读取jdbc.properties文件 -->
        <context:property-placeholder location="jdbc.properties"/>
        <!-- Spring dbcp连接池配置,配置数据源 -->
        <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
            <property name="driverClassName" value="${jdbc.driverClassName}"/>
            <property name="url" value="${jdbc.url}"/>
            <property name="username" value="${jdbc.username}"/>
            <property name="password" value="${jdbc.password}"/>
        </bean>
        <!-- 导入Springjdbc -->
        <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
            <!-- 引入数据源,也就是连接池配置 -->
            <property name="dataSource" ref="dataSource"></property>
        </bean>
      
        <!-- 实例化两个接口 -->
        <bean id="studentDao" class="com.maya.daoImp.StudentDaoImpl">
            <!-- 在dao类中注入Spring的jdbcTemplate -->
            <property name="jdbcTemplate" ref="jdbcTemplate"></property>
        </bean>     
        <bean id="studentService" class="com.maya.serviceImp.StudentServiceImpl">
            <property name="studentDao" ref="studentDao"></property>
        </bean>
    </beans>

     jdbc.properties文件

    jdbc.driverClassName=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql://localhost:3306/hibernate?characterEncoding=GBK
    jdbc.username=root
    jdbc.password=

    model类

    package com.maya.model;
    
    public class Student {
    
        private int id;
        private String name;
        private int age;
        public Student() {
            super();
            // TODO Auto-generated constructor stub
        }
        public Student(String name, int age) {
            super();
            this.name = name;
            this.age = age;
        }
        public Student(int id, String name, int age) {
            super();
            this.id = id;
            this.name = name;
            this.age = age;
        }
        public int getId() {
            return id;
        }
        public void setId(int id) {
            this.id = id;
        }
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public int getAge() {
            return age;
        }
        public void setAge(int age) {
            this.age = age;
        }
        @Override
        public String toString() {
            return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
    }

    dao类接口就不在这里贴了,直接贴其的实现类

    package com.maya.daoImp;
    
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    import org.springframework.jdbc.core.JdbcTemplate;
    import org.springframework.jdbc.core.RowCallbackHandler;
    import com.maya.dao.StudentDao;
    import com.maya.model.Student;
    
    public class StudentDaoImpl implements StudentDao{
        //利用Spring的jdbc对其进行crud操作
        private JdbcTemplate jdbcTemplate;
        
        public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
            this.jdbcTemplate = jdbcTemplate;
        }
        @Override
        public int addStudent(Student student) {
            String sql="insert into t_student values(null,?,?)";
            //因为Spring的jdbc对原生jdbc进行了封装,在这里给出的是数组方式,当然其底层也是需要将数组进行遍历
            Object []params=new Object[]{student.getName(),student.getAge()};
            return jdbcTemplate.update(sql,params);
        }
        @Override
        public int updateStudent(Student student) {
            String sql="update t_student set name=?,age=? where id=?";
            Object []params=new Object[]{student.getName(),student.getAge(),student.getId()};
            //传入两个参数
            return jdbcTemplate.update(sql,params);
        }
        @Override
        public int deleteStudent(int id) {
            String sql="delete from t_student where id=?";
            Object []params=new Object[]{id};
            return jdbcTemplate.update(sql,params);
        }
        @Override
        public List<Student> findStudents() {
            String sql="select * from t_student";
            //这里的list对象必须是个final常量
            final List<Student> studentList=new ArrayList<Student>();
            //同样也是传入两个参数,
            //第二个参数:是一个回掉方法,我们要实现它的processRow方法
            jdbcTemplate.query(sql, new RowCallbackHandler(){
                @Override
                public void processRow(ResultSet rs) throws SQLException {
                    //同jdbc一样也是要在其中把结果集遍历出来,赋值给新对象
                    Student student=new Student();
                    student.setId(rs.getInt("id"));
                    student.setName(rs.getString("name"));
                    student.setAge(rs.getInt("age"));
                    studentList.add(student);
                }            
            });
            return studentList;
        }
    }

    service的接口也不再这里贴了,直接贴其实现类

    package com.maya.serviceImp;
    
    import java.util.List;
    
    import com.maya.dao.StudentDao;
    import com.maya.model.Student;
    import com.maya.service.StudentService;
    
    
    public class StudentServiceImpl implements StudentService{
        private StudentDao studentDao;
        public void setStudentDao(StudentDao studentDao) {
            this.studentDao = studentDao;
        }
        
        //当调用该逻辑时,将其执行的结果条数返回
        @Override
        public int addStudent(Student student) {
            return studentDao.addStudent(student);
        }
        @Override
        public int updateStudent(Student student) {
            return studentDao.updateStudent(student);
        }
        @Override
        public int deleteStudent(int id) {
            return studentDao.deleteStudent(id);
        }
        @Override
        public List<Student> findStudents() {
            return studentDao.findStudents();
        }
    }

    测试类

    package com.maya.test;
    import java.util.List;
    import org.junit.Before;
    import org.junit.Test;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import com.maya.model.Student;
    import com.maya.service.StudentService;
    import junit.framework.TestCase;
    public class T extends TestCase {
    
        private ApplicationContext ac;
    
        @Before//利用前置通知执行
        public void setUp() throws Exception {
            ac=new ClassPathXmlApplicationContext("beans.xml");
        }
        @Test
        public void testaddStudent() {
            StudentService studentService=(StudentService)ac.getBean("studentService");
            int addNums=studentService.addStudent(new Student("王五", 1));
            if(addNums==1){
                System.out.println("添加成功");
            }
        }    
        @Test
        public void testupdateStudent() {
            StudentService studentService=(StudentService)ac.getBean("studentService");
            int updateNums=studentService.updateStudent(new Student(3,"王五2", 2));
            if(updateNums==1){
                System.out.println("更新成功");
            }
        }    
        @Test
        public void testdeleteStudent() {
            StudentService studentService=(StudentService)ac.getBean("studentService");
            int deleteNums=studentService.deleteStudent(3);
            if(deleteNums==1){
                System.out.println("删除成功");
            }
        }    
        @Test
        public void testfindStudents() {
            StudentService studentService=(StudentService)ac.getBean("studentService");
            List<Student> studentList=studentService.findStudents();
            for(Student student:studentList){
                System.out.println(student);
            }
        }
    }

    ***************************************************************************************************************** 

    如何使用JDBCTemplate(在上面已经列出了其增删改查的使用方式,这里在介绍一下xml文件中的配置和查询单个对象,多个对象集合)

      <!-- 配置JDBCTemplate -->
        <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
            <property name="dataSource" ref="dataSource"></property>
        </bean>
        <!-- 命名的JDBCTemplate -->
        <bean id="namedParameterJdbcTemplate" class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
            <constructor-arg name="dataSource" ref="dataSource"></constructor-arg>
        </bean>

    查询

    package com.itnba.maya.test;
    
    import java.sql.Connection;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    
    import javax.sql.DataSource;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.springframework.jdbc.core.BeanPropertyRowMapper;
    import org.springframework.jdbc.core.JdbcTemplate;
    import org.springframework.jdbc.core.RowMapper;
    
    import com.itnba.maya.entities.Nation;
    import com.mchange.v2.c3p0.ComboPooledDataSource;
    
    public class TestC3P0 {
        
    public static void main(String[] args) throws Exception{
            
            ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
            DataSource ds = (DataSource) context.getBean("dataSource");
            JdbcTemplate j = (JdbcTemplate)context.getBean("jdbcTemplate");
            
            String sql = "select count(*) from nation";
            //查询单行单列
            long count = j.queryForObject(sql, Long.class);
    
            System.out.println(count);
            
        }
        
        public static void main77(String[] args) throws Exception{
            
            ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
            DataSource ds = (DataSource) context.getBean("dataSource");
            JdbcTemplate j = (JdbcTemplate)context.getBean("jdbcTemplate");
            
            String sql = "select * from nation";
            //查询多行
            RowMapper<Nation> rowMapper = new BeanPropertyRowMapper<Nation>(Nation.class);
            List<Nation> list = j.query(sql, rowMapper);
            
            for(Nation data : list){
                System.out.println(data);
            }
            
        }
        
        public static void main66(String[] args) throws Exception{
            
            ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
            DataSource ds = (DataSource) context.getBean("dataSource");
            JdbcTemplate j = (JdbcTemplate)context.getBean("jdbcTemplate");
            
            String sql = "select * from nation where code=?";
            //查询单个
            RowMapper<Nation> rowMapper = new BeanPropertyRowMapper<Nation>(Nation.class);
            Nation data = j.queryForObject(sql,rowMapper,"n003");
            
            System.out.println(data);
            
        }
    
    }
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  • 原文地址:https://www.cnblogs.com/AnswerTheQuestion/p/6641347.html
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