使用c3p0連線資料庫實現增刪改查
阿新 • • 發佈：2019-02-18
學習spring之前，視訊中先給我們一個任務就是用c3p0連線資料庫來完成增刪改查
一,、準備
JAR包：
既然是連線資料庫第一個最重要的就是資料庫的驅動包mysql-connection-java-5.1.44-bin.jar
接著就是C3P0-0.9.2.1.jar以及mchange-commons-java-0.2.3.4.jar
然後還少不了dbutils 使用的是commons-dbutils-1.7.jar
一共是4個JAR包
二、配置
配置資料庫連線:
建立c3p0-config.xml的配置檔案，裡面包含連線資料庫的資訊
<?xml version="1.0" encoding="UTF-8"?> <c3p0-config> <default-config> <property name="driverClass">com.mysql.jdbc.Driver</property> <property name="jdbcUrl">jdbc:mysql://localhost:3306/mybatis</property> <property name="user">root</property> <property name="password">123</property> <property name="acquireIncrement">5</property> <property name="initialPoolSize">10</property> <property name="minPoolSize">5</property> <property name="maxPoolSize">20</property> </default-config> </c3p0-config>
建立C3P0Util.java 使用ComboPooledDataSource的物件獲取資料庫連線
package util; import java.sql.Connection; import java.sql.SQLException; import javax.sql.DataSource; import com.mchange.v2.c3p0.ComboPooledDataSource; public class C3P0Util { private static ComboPooledDataSource ds=new ComboPooledDataSource(); //獲取資料來源 public static DataSource getDataSource(){ return ds; } //獲取一個連線 public static Connection getConnection() throws SQLException{ return ds.getConnection(); } }
由於沒有使用Mybatis的逆向工程，這裡需要手動建立Customer.java 用於獲取資料庫表的所有列
package domain;
import java.io.Serializable;
public class Customer implements Serializable{
private int cust_id;
private String cust_name;
private String cust_source;
private String cust_industry;
private String cust_level;
private String cust_address;
private String cust_phone;
public int getCust_id() {
return cust_id;
}
public void setCust_id(int cust_id) {
this.cust_id = cust_id;
}
public String getCust_name() {
return cust_name;
}
public void setCust_name(String cust_name) {
this.cust_name = cust_name;
}
public String getCust_source() {
return cust_source;
}
public void setCust_source(String cust_source) {
this.cust_source = cust_source;
}
public String getCust_industry() {
return cust_industry;
}
public void setCust_industry(String cust_industry) {
this.cust_industry = cust_industry;
}
public String getCust_level() {
return cust_level;
}
public void setCust_level(String cust_level) {
this.cust_level = cust_level;
}
public String getCust_address() {
return cust_address;
}
public void setCust_address(String cust_address) {
this.cust_address = cust_address;
}
public String getCust_phone() {
return cust_phone;
}
public void setCust_phone(String cust_phone) {
this.cust_phone = cust_phone;
}
@Override
public String toString() {
return "Customer [cust_id=" + cust_id + ", cust_name=" + cust_name
+ ", cust_source=" + cust_source + ", cust_industry="
+ cust_industry + ", cust_level=" + cust_level
+ ", cust_address=" + cust_address + ", cust_phone="
+ cust_phone + "]";
}
}
三、介面
上面的配置檔案和資料庫表資訊檔案都已經寫好了，現在需要寫兩個介面提供所有的增刪改查的方法
建立ICustomerDao.java 持久層介面 ，也就是最底層和資料庫連線的介面類
package dao;
import java.util.List;
import domain.Customer;
public interface ICustomerDao {
List<Customer> findAllCustomer();
void saveCustomer(Customer customer);
void updateCustomer(Customer customer);
void deleteCustomer(int custId);
Customer findCustomerById(int custId);
}
建立ICustomerService.java 業務層介面，用於持久層和客戶端連線的介面類，和Dao的方法一樣
package service;
import java.util.List;
import domain.Customer;
public interface ICustomerService {
//查詢所有客戶
List<Customer> findAllCustomer();
//儲存客戶資訊
void saveCustomer(Customer customer);
//更改客戶資訊
void updateCustomer(Customer customer);
//根據Id刪除物件
void deleteCustomer(int cust_id);
//根據ID查詢使用者，返回使用者資訊
Customer findCustomerById(int cust_id);
}四、實現類
建立CustomerDao.java 實現Dao介面，利用C3P0裡的QueryRunner類獲取到資料庫連線資訊連線資料庫
並將SQL語句傳給資料庫然後得到SQL的返回值。
package dao.impl;
import java.sql.SQLException;
import java.util.List;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import dao.ICustomerDao;
import domain.Customer;
import util.C3P0Util;
//客戶的持久層實現類
public class CustomerDao implements ICustomerDao {
private QueryRunner runner=new QueryRunner(C3P0Util.getDataSource());
@Override
public List<Customer> findAllCustomer() {
try {
return runner.query("select * from cst_customer", new BeanListHandler<Customer>(Customer.class));
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
@Override
public void saveCustomer(Customer customer) {
try {
runner.update("insert into cst_customer(cust_name,cust_source,cust_industry,cust_level,cust_address,cust_phone)values(?,?,?,?,?,?)",
customer.getCust_name(),customer.getCust_source(),customer.getCust_industry(),
customer.getCust_level(),customer.getCust_address(),customer.getCust_phone());
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
@Override
public void updateCustomer(Customer customer) {
try {
runner.update("update cst_customer set cust_name=?,cust_source=?,cust_industry=?,cust_level=?,cust_address=?,cust_phone=? where cust_id=?",
customer.getCust_name(),customer.getCust_source(),customer.getCust_industry(),
customer.getCust_level(),customer.getCust_address(),customer.getCust_phone(),customer.getCust_id());
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
@Override
public void deleteCustomer(int custId) {
try {
runner.update("delete from cst_customer where cust_id=?",custId);
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
@Override
public Customer findCustomerById(int custId) {
try {
return runner.query("select * from cst_customer where cust_id=?", new BeanHandler<Customer>(Customer.class),custId);
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
建立CustomerService.java 實現業務層，將需要查詢的資料傳給Dao層，並得到Dao層的返回值。
package service;
import java.util.List;
import dao.ICustomerDao;
import dao.impl.CustomerDao;
import domain.Customer;
//客戶的業務層實現類
public class CustomerServiceImpl implements ICustomerService {
private ICustomerDao customerDao=new CustomerDao();
@Override
public List<Customer> findAllCustomer() {
// TODO Auto-generated method stub
return customerDao.findAllCustomer();
}
@Override
public void saveCustomer(Customer customer) {
customerDao.saveCustomer(customer);
}
@Override
public void updateCustomer(Customer customer) {
customerDao.updateCustomer(customer);
}
@Override
public void deleteCustomer(int custId) {
customerDao.deleteCustomer(custId);
}
@Override
public Customer findCustomerById(int custId) {
// TODO Auto-generated method stub
return customerDao.findCustomerById(custId);
}
}五、測試類
建立CustomerServiceTest.java 獲取CustomerServiceImpl所有方法的測試方法
該類中在方法裡建立CustomerServiceImpl物件 獲取原始方法，將引數傳入Customer中，通過CustomerService獲取到返回值並列印。
package test;
import static org.junit.Assert.fail;
import java.util.List;
import org.junit.Test;
import domain.Customer;
import service.CustomerServiceImpl;
import service.ICustomerService;
public class CustomerServicerTest {
@Test
public void testFindAllCustomer() {
ICustomerService cs=new CustomerServiceImpl();
List<Customer> list=cs.findAllCustomer();
for(Customer c: list){
System.out.println(c);
}
}
@Test
public void testSaveCustomer() {
ICustomerService cs=new CustomerServiceImpl();
Customer c=new Customer();
c.setCust_name("滴滴");
c.setCust_source("dache");
cs.saveCustomer(c);
}
@Test
public void testUpdateCustomer() {
fail("Not yet implemented");
}
@Test
public void testDeleteCustomer() {
fail("Not yet implemented");
}
@Test
public void testFindCustomerById() {
ICustomerService cs=new CustomerServiceImpl();
Customer c=cs.findCustomerById(2);
System.out.println(c);
}
}至此C3P0連線資料庫進行單表增刪改查功能完結。附上結構圖
