首先看下我們的目標(biāo)：向mysql數(shù)據(jù)庫中批量插入10000條數(shù)據(jù)

操作環(huán)境：Mysql和Java代碼都運行在我本地Windows電腦(i7處理器，4核，16G運行內(nèi)存，64位操作系統(tǒng)

1、JPA單線程執(zhí)行

代碼省略，大概需要39S左右

2、JPA多線程執(zhí)行

大概需要37S左右，并沒有想象中的快很多

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原因： 多線程只是大大提高了程序處理數(shù)據(jù)的時間，并不會提高插入數(shù)據(jù)庫的時間，相反在我這邊JPA的框架下，多線程也就意味著多連接，反而更加消耗數(shù)據(jù)庫性能

package com.example.demo.controller;  import com.example.demo.entity.Student; import com.example.demo.service.StudentServiceInterface; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController;  import javax.xml.bind.ValidationException; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors;  @RestController @RequestMapping("/student") public class StudentController {      @Autowired     private StudentServiceInterface studentServiceInterface;      // 來使主線程等待線程池中的線程執(zhí)行完畢     private CountDownLatch threadsSignal;      // 每個線程處理的數(shù)據(jù)量     private static final int count = 1000;     // 我的電腦為4核 線程池大小設(shè)置為2N+1     private static ExecutorService execPool = Executors.newFixedThreadPool(9);          /**      * 多線程保存      *      * @return      * @throws ValidationException      */     @GetMapping()     public String saveStudentEnableThread() throws ValidationException {         Long begin = new Date().getTime();         // 需要插入數(shù)據(jù)庫的數(shù)據(jù)         List<Student> list = new ArrayList<>();         for (int i = 0; i < 10000; i++) {             Student student = new Student();             student.setName("張三");             student.setAge(10);             list.add(student);         }         try {             if (list.size() <= count) {                 threadsSignal = new CountDownLatch(1);                 execPool.submit(new InsertDate(list));             } else {                 List<List<Student>> lists = dealData(list, count);                 threadsSignal = new CountDownLatch(lists.size());                 for (List<Student> students : lists) {                     execPool.submit(new InsertDate(students));                 }             }             threadsSignal.await();         } catch (Exception e) {             System.out.println(e.toString() + " 錯誤所在行數(shù)：" + e.getStackTrace()[0].getLineNumber());         }         // 結(jié)束時間         Long end = new Date().getTime();         return "10000條數(shù)據(jù)插入花費時間 : " + (end - begin) / 1000 + " s";     }      /**      * 數(shù)據(jù)組裝      * 把每個線程要處理的數(shù)據(jù) 再組成一個List      * 我這邊就是把10000條數(shù)據(jù) 組成 10個1000條的集合      *      * @param target 數(shù)據(jù)源      * @param size   每個線程處理的數(shù)量      * @return      */     public static List<List<Student>> dealData(List<Student> target, int size) {         List<List<Student>> threadList = new ArrayList<List<Student>>();         // 獲取被拆分的數(shù)組個數(shù)         int arrSize = target.size() % size == 0 ? target.size() / size : target.size() / size + 1;         for (int i = 0; i < arrSize; i++) {             List<Student> students = new ArrayList<Student>();             //把指定索引數(shù)據(jù)放入到list中             for (int j = i * size; j <= size * (i + 1) - 1; j++) {                 if (j <= target.size() - 1) {                     students.add(target.get(j));                 }             }             threadList.add(students);         }         return threadList;     }      /**      * 內(nèi)部類,開啟線程批量保存數(shù)據(jù)      */     class InsertDate extends Thread {         List<Student> list = new ArrayList<Student>();         public InsertDate(List<Student> students) {             list = students;         }         public void run() {             try {                 // 與數(shù)據(jù)庫交互                 studentServiceInterface.save(list);                 threadsSignal.countDown();             } catch (ValidationException e) {                 e.printStackTrace();             }         }     } }

3、傳統(tǒng)JDBC插入

大概需要8S左右，相較于前兩種方式已經(jīng)快很多了，代碼如下：

package com.example.demo.controller;  import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController;  import javax.xml.bind.ValidationException; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.util.Date;  @RestController @RequestMapping("/student1") public class StudentController1 {      @GetMapping()     public String saveStudentEnableThread() throws ValidationException {         // 開始時間         Long begin = new Date().getTime();         Connection connection = null;         try {             connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/db01?characterEncoding=utf8&useUnicode=true&useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true", "admin", "123456");//獲取連接             if (connection != null) {                 System.out.println("獲取連接成功");             } else {                 System.out.println("獲取連接失敗");             }             //這里必須設(shè)置為false，我們手動批量提交             connection.setAutoCommit(false);             //這里需要注意，SQL語句的格式必須是預(yù)處理的這種，就是values(?,?,...,?)，否則批處理不起作用             PreparedStatement statement = connection.prepareStatement("insert into student(id,`name`,age) values(?,?,?)");             // 塞數(shù)據(jù)             for (int i = 0; i < 10000; i++) {                 statement.setInt(1, i+1);                 statement.setString(2, "張三");                 statement.setInt(3, 10);                 //將要執(zhí)行的SQL語句先添加進去，不執(zhí)行                 statement.addBatch();             }             // 提交要執(zhí)行的批處理，防止 JDBC 執(zhí)行事務(wù)處理             statement.executeBatch();             connection.commit();             // 關(guān)閉相關(guān)連接             statement.close();             connection.close();         } catch (Exception e) {             e.printStackTrace();         }         // 結(jié)束時間         Long end = new Date().getTime();         // 耗時         System.out.println("10000條數(shù)據(jù)插入花費時間 : " + (end - begin) / 1000 + " s");         return "10000條數(shù)據(jù)插入花費時間 : " + (end - begin) / 1000 + " s";     }  }

4、最后檢查一下數(shù)據(jù)是否成功存庫，一共30000條，沒有丟數(shù)據(jù)

完成！