Batch database opreations execute mlutiple table modifications over a single database connection, reducing overhead compared to separate single-statement cals.

package com.example.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.io.Serializable;
@NoArgsConstructor
@AllArgsConstructor
@Data
public class Department implements Serializable {
    private Integer id;
    private String deptName;
    private String location;
}

package com.example.service;
import com.example.entity.Department;
import java.util.List;
public interface DepartmentService {
    int[] batchInsertDepartments(List<Department> deptList);
    int[] batchModifyDepartments(List<Department> deptList);
    int[] batchRemoveDepartmentsById(List<Integer> idList);
}

package com.example.service.impl;
import com.example.dao.DepartmentDao;
import com.example.entity.Department;
import com.example.service.DepartmentService;
import org.springframework.stereotype.Service;
import org.springframework.beans.factory.annotation.Autowired;
import java.util.List;
@Service
public class DepartmentServiceImpl implements DepartmentService {
    @Autowired
    private DepartmentDao departmentDao;
    @Override
    public int[] batchInsertDepartments(List<Department> deptList) {
        return departmentDao.batchInsert(deptList);
    }
    @Override
    public int[] batchModifyDepartments(List<Department> deptList) {
        return departmentDao.batchUpdate(deptList);
    }
    @Override
    public int[] batchRemoveDepartmentsById(List<Integer> idList) {
        return departmentDao.batchDelete(idList);
    }
}

package com.example.dao;
import com.example.entity.Department;
import java.util.List;
public interface DepartmentDao {
    int[] batchInsert(List<Department> deptList);
    int[] batchUpdate(List<Department> deptList);
    int[] batchDelete(List<Integer> idList);
}

package com.example.dao.impl;
import com.example.dao.DepartmentDao;
import com.example.entity.Department;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import org.springframework.beans.factory.annotation.Autowired;
import java.util.ArrayList;
import java.util.List;
@Repository
public class DepartmentDaoImpl implements DepartmentDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;
    @Override
    public int[] batchInsert(List<Department> deptList) {
        String insertSql = "INSERT INTO department (dept_name, location) VALUES (?, ?)";
        List<Object[]> paramList = new ArrayList<>();
        deptList.forEach(dept -> {
            Object[] params = {dept.getDeptName(), dept.getLocation()};
            paramList.add(params);
        });
        return jdbcTemplate.batchUpdate(insertSql, paramList);
    }
    @Override
    public int[] batchUpdate(List<Department> deptList) {
        String updateSql = "UPDATE department SET dept_name = ?, location = ? WHERE id = ?";
        List<Object[]> paramList = new ArrayList<>();
        deptList.forEach(dept -> {
            Object[] params = {dept.getDeptName(), dept.getLocation(), dept.getId()};
            paramList.add(params);
        });
        return jdbcTemplate.batchUpdate(updateSql, paramList);
    }
    @Override
    public int[] batchDelete(List<Integer> idList) {
        String deleteSql = "DELETE FROM department WHERE id = ?";
        List<Object[]> paramList = new ArrayList<>();
        idList.forEach(id -> {
            Object[] params = {id};
            paramList.add(params);
        });
        return jdbcTemplate.batchUpdate(deleteSql, paramList);
    }
}

package com.example.test;
import com.example.entity.Department;
import com.example.service.DepartmentService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.util.LinkedList;
import java.util.List;
import java.util.Arrays;
public class BatchTest {
    @Test
    public void testBatchInsert() {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("spring-dao.xml");
        DepartmentService service = ctx.getBean(DepartmentService.class);
        List<Department> depts = new LinkedList<>();
        for (int j = 0; j < 8; j++) {
            depts.add(new Department(null, "TechTeam-" + j, "Office-" + j));
        }
        int[] results = service.batchInsertDepartments(depts);
        System.out.println(Arrays.toString(results));
    }
    @Test
    public void testBatchUpdate() {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("spring-dao.xml");
        DepartmentService service = ctx.getBean(DepartmentService.class);
        List<Department> depts = new LinkedList<>();
        for (int j = 40; j <= 47; j++) {
            depts.add(new Department(j, "Updated-Name", "Updated-Loc"));
        }
        int[] results = service.batchModifyDepartments(depts);
        System.out.println(Arrays.toString(results));
    }
    @Test
    public void testBatchDelete() {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("spring-dao.xml");
        DepartmentService service = ctx.getBean(DepartmentService.class);
        List<Integer> ids = new LinkedList<>();
        for (int j = 40; j <= 55; j++) {
            ids.add(j);
        }
        int[] results = service.batchRemoveDepartmentsById(ids);
        System.out.println(Arrays.toString(results));
    }
}