Spring学习笔记----JdbcTemplet和NamedParameterJdbcTemplate的使用
JdbcTemplet是Spring下一个很好用的jdbc小工具，而且使用起来也是很简单
需求：实现基本的数据库操作
贴上代码：
dataSource.properties
jdbc.user = root
jdbc.password =123456
jdbc.driverClass = com.mysql.jdbc.Driver
jdbc.jdbcUrl = jdbc:mysql:///spring1
jdbc.initPoolSize=5
jdbc.maxPoolSize=10applicationContext.xml
package cn.limbo.spring.jdbc;
/**
* Created by Limbo on 16/7/14.
*/
public class Student {
private int id;
private String studentName;
private String email;
private int deptId;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getStudentName() {
return studentName;
}
public void setStudentName(String studentName) {
this.studentName = studentName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public int getDeptId() {
return deptId;
}
public void setDeptId(int deptId) {
this.deptId = deptId;
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
", studentName='" + studentName + '\'' +
", email='" + email + '\'' +
", deptId=" + deptId +
'}';
}
}
Department.java
package cn.limbo.spring.jdbc;
/**
* Created by Limbo on 16/7/14.
*/
public class Department {
private int id;
private String name;
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;
}
@Override
public String toString() {
return "Department{" +
"id=" + id +
", name='" + name + '\'' +
'}';
}
}
package cn.limbo.spring.jdbc;
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 org.springframework.jdbc.core.namedparam.BeanPropertySqlParameterSource;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;
import javax.sql.DataSource;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Created by Limbo on 16/7/14.
*/
public class JDBCTest {
private static ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
private static JdbcTemplate jdbcTemplate = (JdbcTemplate) ctx.getBean("jdbcTemplate");
private static NamedParameterJdbcTemplate namedParameterJdbcTemplate = ctx.getBean(NamedParameterJdbcTemplate.class);
public void testDataSource() throws SQLException {
DataSource dataSource = ctx.getBean(DataSource.class);
System.out.println(dataSource.getConnection());
}
/**
* 执行UPDATE,INSERT,DELETE
*/
public static void testUpdate()
{
String sql = "UPDATE student SET student_name = ? WHERE id = ?";
jdbcTemplate.update(sql,"Kylin",2);
}
/**
* 批量INSERT,UPDATE,DELETE
* 最后一个参数是Object[]的list类型,因为修改一条记录需要一个object数组,那么多条就需要多个
*/
public static void BatchUpdate()
{
String sql = "INSERT INTO student(id,student_name,email,Dept_No)VALUES(?,?,?,?)";
List batchArgs = new ArrayList<>();
batchArgs.add(new Object[]{4,"AA","[email protected]",1});
batchArgs.add(new Object[]{5,"BB","[email protected]",2});
batchArgs.add(new Object[]{6,"CC","[email protected]",1});
batchArgs.add(new Object[]{7,"DD","[email protected]",2});
batchArgs.add(new Object[]{8,"EE","[email protected]",1});
jdbcTemplate.batchUpdate(sql,batchArgs);
}
/**
* 从数据库中获取一条记录,实际得到一个对象
* 注意不是调用这个方法queryForObject(java.lang.String sql,java.lang.Class requiredType,java.lang.Object... args)
* 需要调用中这个方法: queryForObject(java.lang.String sql,@NotNull org.springframework.jdbc.core.RowMapper rowMapper,java.lang.Object... args)
* 1.其中的RowMapper指定如何去映射结果集的行,常用的实现类为BeanPropertyRowMapper<>(Student.class);
* 2.使用SQL中的列的别名完成列名和类的属性名的映射
* 3.不支持级联属性
*/
public static void testQueryForObject()
{
String sql = "SELECT id,student_name,email,Dept_No FROM student WHERE id = ?";
RowMapper rowMapper = new BeanPropertyRowMapper<>(Student.class);
Student student = jdbcTemplate.queryForObject(sql,rowMapper,1);
System.out.println(student);
}
/**
* 查到实体类的集合
* 注意不是调用queryForList
*/
public static void testQueryForList()
{
String sql = "SELECT id, student_name,email,Dept_No FROM student WHERE id > ?";
RowMapper rowMapper = new BeanPropertyRowMapper<>(Student.class);
List list = jdbcTemplate.query(sql,rowMapper,1);
System.out.println(list);
}
/**
* 获取单个列的值,或者做统计查询
*/
public static void testQueryForObject2()
{
String sql = "SELECT count(id) FROM student";
int count = jdbcTemplate.queryForObject(sql,Integer.class);
System.out.println(count);
}
/**
* 可以为参数取名字,参数多了更加便于维护
* 1.好处:若有多个参数,则不用再去对应位置,直接对应参数名,便于维护
* 2.缺点:较为麻烦
*/
public static void testNamedParameterJdbcTemplate()
{
String sql = "INSERT INTO student(id,student_name,email,Dept_No) VALUES(:id,:name,:email,:deptid)";
Map paramMap = new HashMap<>();
paramMap.put("id",9);
paramMap.put("name","Limbo");
paramMap.put("email","[email protected]");
paramMap.put("deptid",1);
namedParameterJdbcTemplate.update(sql,paramMap);
}
/**
* 使用具名参数的时候,可以用update(java.lang.String sql,org.springframework.jdbc.core.namedparam.SqlParameterSource paramSource)进行更新操作
* 直接将一个对象作为参数
* 1.SQL语句中的参数名和类的属性一致
* 2.使用SqlParameterSource的BeanPropertySqlParameterSource 实现类作为参数
*/
public static void testNamedParameterJdbcTemplate2()
{
String sql = "INSERT INTO student(id,student_name,email,Dept_No) VALUES(:id,:studentName,:email,:deptId)";
Student student = new Student();
student.setStudentName("wyh");
student.setId(10);
student.setEmail("[email protected]");
student.setDeptId(1);
SqlParameterSource paramSource = new BeanPropertySqlParameterSource(student);
namedParameterJdbcTemplate.update(sql,paramSource);
}
public static void main(String[] args) {
testNamedParameterJdbcTemplate2();
}
}
以上就是用JdbcTemplet和NamedParameterJdbcTemplate实现的增删改查，当然需要取出一个实体的时候可以这样写
StudentDao.java
package cn.limbo.spring.jdbc;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Repository;
/**
* Created by Limbo on 16/7/15.
*/
@Repository
public class StudentDao{
@Autowired
private JdbcTemplate jdbcTemplate;
public Student get(int id)
{
String sql = "SELECT * FROM student WHERE id = ?";
RowMapper rowMapper = new BeanPropertyRowMapper<>(Student.class);
Student student = jdbcTemplate.queryForObject(sql,rowMapper,1);
return student;
}
}