Java Druid資料庫連線池+SpringJDBC

Water_tu發表於2020-10-29

Druid的配置檔案 druid.properties

driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/db1?serverTimezone=UTC
username=root
password=root
# 初始化連線數量
initialSize=5
# 最大連線數
maxActive=10
# 最大等待時間
maxWait=3000

對 Druid的封裝工具類

package cn.itcast.utils;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

/**
 * Druid連線池的工具類
 *
 * Druid:資料庫連線池實現技術,由阿里巴巴提供的
 * 匯入jar包 druid-1.0.9.jar
 *  匯入mysql驅動java包
 * 定義配置檔案:* 是properties形式的,如 druid.properties
 *
 */
public class JDBCUtils {

    //1.定義成員變數 DataSource
    private static DataSource ds ;

    static{
        try {
            //1.載入配置檔案
            Properties pro = new Properties();
            pro.load(JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties"));
            //2.獲取DataSource
            ds = DruidDataSourceFactory.createDataSource(pro);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 獲取連線
     */
    public static Connection getConnection() throws SQLException {
        return ds.getConnection();
    }

    /**
     * 釋放資源
     */
    public static void close(Statement stmt,Connection conn){
       /* if(stmt != null){
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if(conn != null){
            try {
                conn.close();//歸還連線
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }*/

       close(null,stmt,conn);
    }


    public static void close(ResultSet rs , Statement stmt, Connection conn){


        if(rs != null){
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }


        if(stmt != null){
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if(conn != null){
            try {
                conn.close();//歸還連線
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 獲取連線池方法
     */

    public static DataSource getDataSource(){
        return  ds;
    }

}

 測試demo

package cn.itcast.jdbc;

import cn.itcast.utils.JDBCUtils;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import org.junit.Test;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.RowMapper;
import java.sql.ResultSet;

import java.util.List;
import java.util.Map;
import java.sql.Date;

import cn.itcast.domain.Emp;

public class Druid_SpringJDBC_Demo {


    public static void main(String[] args) throws SQLException {
       // TestDruid();
        // TestSpringJDBC();

    }

    //測試 Druid資料庫連線池
   public static void TestDruid() {
       /*
        * 完成新增操作:給account表新增一條記錄
        */
       Connection conn = null;
       PreparedStatement pstmt = null;
       try {
           //1.獲取連線
           conn = JDBCUtils.getConnection();
           //2.定義sql
           String sql = "insert into account values(null,?,?)";
           //3.獲取pstmt物件
           pstmt = conn.prepareStatement(sql);
           //4.給?賦值
           pstmt.setDouble(1, 3000);
           pstmt.setString(2, "wangwu");
           //5.執行sql
           int count = pstmt.executeUpdate();
           System.out.println(count);
       } catch (SQLException e) {
           e.printStackTrace();
       } finally {
           //6. 釋放資源
           JDBCUtils.close(pstmt, conn);
       }
   }

       /*
       * 測試Spring JDBC
       *
       *   匯入jar包
       * spring-beans-5.0.0.RELEASE.jar
       * spring-core-5.0.0.RELEASE.jar
       * spring-jdbc-5.0.0.RELEASE.jar
       * spring-tx-5.0.0.RELEASE.jar
       * commons-logging-1.2.jar
       * */
       public static void TestSpringJDBC()
       {
           //1 匯入jar包
           //2.建立JDBCTemplate物件
           JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());
           //3.呼叫方法
           String sql = "update account set balance = 5000 where id = ?";
           int count = template.update(sql, 3);
           System.out.println(count);
       }

//--------------------------------------------------------------------------------------------

    //1. 獲取JDBCTemplate物件
    private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());
    /**
     * 1. 修改1號資料的 salary 為 10000
     */
    @Test
    public void test1(){

        //2. 定義sql
        String sql = "update emp set salary = 10000 where id = 1";
        //3. 執行sql
        int count = template.update(sql);
        System.out.println(count);
    }

    /**
     * 2. 新增一條記錄
     */
    @Test
    public void test2(){
        String sql = "insert into emp(id,ename,dept_id) values(?,?,?)";
        int count = template.update(sql, 1015, "郭靖", 10);
        System.out.println(count);

    }

    /**
     * 3.刪除剛才新增的記錄
     */
    @Test
    public void test3(){
        String sql = "delete from emp where id = ?";
        int count = template.update(sql, 1015);
        System.out.println(count);
    }

    /**
     * 4.查詢id為1001的記錄,將其封裝為Map集合
     * 注意:這個方法查詢的結果集長度只能是1
     */
    @Test
    public void test4(){
        String sql = "select * from emp where id = ? or id = ?";
        Map<String, Object> map = template.queryForMap(sql, 1001,1002);
        System.out.println(map);
        //{id=1001, ename=孫悟空, job_id=4, mgr=1004, joindate=2000-12-17, salary=10000.00, bonus=null, dept_id=20}

    }

    /**
     * 5. 查詢所有記錄,將其封裝為List
     */
    @Test
    public void test5(){
        String sql = "select * from emp";
        List<Map<String, Object>> list = template.queryForList(sql);

        for (Map<String, Object> stringObjectMap : list) {
            System.out.println(stringObjectMap);
        }
    }

    /**
     * 6. 查詢所有記錄,將其封裝為Emp物件的List集合
     */

    @Test
    public void test6(){
        String sql = "select * from emp";
        List<Emp> list = template.query(sql, new RowMapper<Emp>() {

            @Override
            public Emp mapRow(ResultSet rs, int i) throws SQLException {
                Emp emp = new Emp();
                int id = rs.getInt("id");
                String ename = rs.getString("ename");
                int job_id = rs.getInt("job_id");
                int mgr = rs.getInt("mgr");
                Date joindate = rs.getDate("joindate");
                double salary = rs.getDouble("salary");
                double bonus = rs.getDouble("bonus");
                int dept_id = rs.getInt("dept_id");

                emp.setId(id);
                emp.setEname(ename);
                emp.setJob_id(job_id);
                emp.setMgr(mgr);
                emp.setJoindate(joindate);
                emp.setSalary(salary);
                emp.setBonus(bonus);
                emp.setDept_id(dept_id);

                return emp;
            }
        });


        for (Emp emp : list) {
            System.out.println(emp);
        }
    }

    /**
     * 6. 查詢所有記錄,將其封裝為Emp物件的List集合
     */

    @Test
    public void test6_2(){
        String sql = "select * from emp";
        List<Emp> list = template.query(sql, new BeanPropertyRowMapper<Emp>(Emp.class));
        for (Emp emp : list) {
            System.out.println(emp);
        }
    }

    /**
     * 7. 查詢總記錄數
     */

    @Test
    public void test7(){
        String sql = "select count(id) from emp";
        Long total = template.queryForObject(sql, Long.class);
        System.out.println(total);
    }



   }


Emp類

package cn.itcast.domain;

import java.util.Date;

public class Emp {
    private Integer id;
    private String ename;
    private Integer job_id;
    private Integer mgr;
    private Date joindate;
    private Double salary;
    private Double bonus;
    private Integer dept_id;


    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getEname() {
        return ename;
    }

    public void setEname(String ename) {
        this.ename = ename;
    }

    public Integer getJob_id() {
        return job_id;
    }

    public void setJob_id(Integer job_id) {
        this.job_id = job_id;
    }

    public Integer getMgr() {
        return mgr;
    }

    public void setMgr(Integer mgr) {
        this.mgr = mgr;
    }

    public Date getJoindate() {
        return joindate;
    }

    public void setJoindate(Date joindate) {
        this.joindate = joindate;
    }

    public Double getSalary() {
        return salary;
    }

    public void setSalary(Double salary) {
        this.salary = salary;
    }

    public Double getBonus() {
        return bonus;
    }

    public void setBonus(Double bonus) {
        this.bonus = bonus;
    }

    public Integer getDept_id() {
        return dept_id;
    }

    public void setDept_id(Integer dept_id) {
        this.dept_id = dept_id;
    }

    @Override
    public String toString() {
        return "Emp{" +
                "id=" + id +
                ", ename='" + ename + '\'' +
                ", job_id=" + job_id +
                ", mgr=" + mgr +
                ", joindate=" + joindate +
                ", salary=" + salary +
                ", bonus=" + bonus +
                ", dept_id=" + dept_id +
                '}';
    }
}

 

 

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