java攻城狮之路--复习JDBC(利用BeanUtils、JDBC元数据编写通用的查询方法;元数据;Blob;事务;批量处理)

时间:2023-03-09 05:10:47
java攻城狮之路--复习JDBC(利用BeanUtils、JDBC元数据编写通用的查询方法;元数据;Blob;事务;批量处理)

1、利用BeanUtils的前提得要加入以下两个jar包:

commons-beanutils-1.8.0.jar

commons-logging-1.1.1.jar

package com.shellway.jdbcDAO;

import java.util.List;
import org.junit.Test; public class TestDAO {
DAO dao = new DAO(); @Test
public void testUpdate() throws Exception {
String sql = "update examstudent set grade=? where flow_id=12345";
dao.update(sql, 88);
} @Test
public void test() throws Exception { String sql = "select flow_id flowID,type,id_card idCard, "
+ "exam_card examCard,student_name studentName,location,grade "
+ "from examstudent where flow_id = ? ";
Student stu = dao.get(Student.class, sql, 12345);
System.out.println(stu);
} @Test
public void testGetSome() throws Exception {
String sql = "select flow_id flowID,type,id_card idCard, "
+ "exam_card examCard,student_name studentName,location,grade "
+ "from examstudent";
List<Student> students = dao.getForList(Student.class, sql);
System.out.println(students);
} @Test
public void testGetForValue() throws Exception {
String sql = "select grade from examstudent where flow_id = ? ";
Object obj = dao.getforvalue(sql, 123456);
System.out.println(obj);
}
}

测试类

package com.shellway.jdbcDAO;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.PreparedStatement;
import java.sql.ResultSetMetaData;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map; import org.apache.commons.beanutils.BeanUtils; public class DAO { public void update(String sql, Object... args) throws Exception {
Connection conn = null;
PreparedStatement ps = null;
try {
conn = JDBCTools.getConnection();
ps = conn.prepareStatement(sql);
for (int i = 0; i < args.length; i++) {
ps.setObject(i + 1, args[i]);
}
ps.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCTools.release(null, ps, conn);
}
} // 获取一个对象通用的方法
public <T> T get(Class<T> clazz, String sql, Object... args)
throws Exception {
T entity = null;
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null; try {
conn = JDBCTools.getConnection();
ps = conn.prepareStatement(sql);
for (int i = 0; i < args.length; i++) {
ps.setObject(i + 1, args[i]);
}
rs = ps.executeQuery();
ResultSetMetaData rsmd = rs.getMetaData();
Map<String, Object> map = null; while (rs.next()) {
map = new HashMap<String, Object>();
for (int i = 0; i < rsmd.getColumnCount(); i++) {
String columnLabel = rsmd.getColumnLabel(i + 1);
Object columnValue = rs.getObject(i + 1);
map.put(columnLabel, columnValue);
}
if (map.size() > 0) {
entity = clazz.newInstance();
for (Map.Entry<String, Object> entry : map.entrySet()) {
String label = entry.getKey();
Object value = entry.getValue();
BeanUtils.setProperty(entity, label, value);
}
}
} } catch (Exception e) {
e.printStackTrace();
} finally {
JDBCTools.release(rs, ps, conn);
}
return entity;
} // 获取一组对象通用的方法
public <T> List<T> getForList(Class<T> clazz, String sql, Object... args)
throws Exception {
T entity = null;
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
List<T> result = new ArrayList<T>(); try {
conn = JDBCTools.getConnection();
ps = conn.prepareStatement(sql);
for (int i = 0; i < args.length; i++) {
ps.setObject(i + 1, args[i]);
}
rs = ps.executeQuery(); ResultSetMetaData rsmd = rs.getMetaData();
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
Map<String, Object> map = new HashMap<String, Object>(); while (rs.next()) {
for (int i = 0; i < rsmd.getColumnCount(); i++) {
String columnLabel = rsmd.getColumnLabel(i + 1);
Object columnValue = rs.getObject(i + 1);
map.put(columnLabel, columnValue);
}
list.add(map);
if (list.size() > 0) {
entity = clazz.newInstance();
for (Map<String, Object> ll : list) {
for (Map.Entry<String, Object> entry : ll.entrySet()) {
String label = entry.getKey();
Object value = entry.getValue();
BeanUtils.setProperty(entity, label, value);
}
}
result.add(entity);
}
} } catch (Exception e) {
e.printStackTrace();
} finally {
JDBCTools.release(rs, ps, conn);
}
return result;
} // 获取一个对象中一列的值通用的方法
public <E> E getforvalue(String sql, Object... args) throws Exception {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
conn = JDBCTools.getConnection();
ps = conn.prepareStatement(sql);
for (int i = 0; i < args.length; i++) {
ps.setObject(i + 1, args[i]);
}
rs = ps.executeQuery();
if (rs.next()) {
return (E) rs.getObject(1);
} } catch (Exception e) {
e.printStackTrace();
} finally {
JDBCTools.release(rs, ps, conn);
}
return null;
}
}

通用的DAO.java

package com.shellway.jdbcDAO;

import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.sql.PreparedStatement; public class JDBCTools { public static <T> T get(Class<T> clazz, String sql, Object... args)
throws Exception {
T entity = null;
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null; try {
conn = JDBCTools.getConnection();
ps = conn.prepareStatement(sql);
for (int i = 0; i < args.length; i++) {
ps.setObject(i + 1, args[i]);
}
rs = ps.executeQuery(); ResultSetMetaData rsmd = rs.getMetaData();
Map<String, Object> map = new HashMap<String, Object>();
while (rs.next()) {
for (int i = 0; i < rsmd.getColumnCount(); i++) {
String columnLabel = rsmd.getColumnLabel(i + 1);
Object columnValue = rs.getObject(i + 1);
// Object columnValue = rs.getObject(columnLabel);
map.put(columnLabel, columnValue);
}
}
if (map.size() > 0) {
entity = clazz.newInstance();
for (Map.Entry<String, Object> values : map.entrySet()) {
String key = values.getKey();
Object value = values.getValue();
ReflectionUtils.setFieldValue(entity, key, value);
}
} } catch (Exception e) {
e.printStackTrace();
} finally {
JDBCTools.release(rs, ps, conn);
}
return entity;
} public static void update(String sql, Object... args) throws Exception {
Connection conn = null;
PreparedStatement ps = null; try {
conn = JDBCTools.getConnection();
ps = conn.prepareStatement(sql);
for (int i = 0; i < args.length; i++) {
ps.setObject(i + 1, args[i]);
}
System.out.println(sql);
ps.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCTools.release(null, ps, conn);
}
} public static Connection getConnection() throws Exception { Properties proper = new Properties();
InputStream in = JDBCTools.class.getClassLoader().getResourceAsStream(
"jdbc.properties");
proper.load(in);
String driverClass = proper.getProperty("driver");
String jdbcUrl = proper.getProperty("jdbcUrl");
String user = proper.getProperty("user");
String password = proper.getProperty("password"); Class.forName(driverClass);
Connection connection = DriverManager.getConnection(jdbcUrl, user,
password);
return connection;
} public static void release(ResultSet rs, Statement state, Connection conn)
throws Exception {
if (rs != null) {
try {
rs.close();
} catch (Exception e) {
e.printStackTrace();
}
}
if (state != null) {
try {
state.close();
} catch (Exception e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (Exception e) {
e.printStackTrace();
}
}
} }

JDBCTools工具类

driver=com.mysql.jdbc.Driver
jdbcUrl=jdbc:mysql://localhost:3306/test
user=root
password=123

配置文件jdbc.properties

package com.shellway.jdbc;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type; /**
* 反射的 Utils 函数集合 提供访问私有变量, 获取泛型类型 Class, 提取集合中元素属性等 Utils 函数
*
* @author Administrator
*
*/
public class ReflectionUtils { /**
* 通过反射, 获得定义 Class 时声明的父类的泛型参数的类型 如: public EmployeeDao extends
* BaseDao<Employee, String>
*
* @param clazz
* @param index
* @return
*/
@SuppressWarnings("unchecked")
public static Class getSuperClassGenricType(Class clazz, int index) {
Type genType = clazz.getGenericSuperclass(); if (!(genType instanceof ParameterizedType)) {
return Object.class;
} Type[] params = ((ParameterizedType) genType).getActualTypeArguments(); if (index >= params.length || index < 0) {
return Object.class;
} if (!(params[index] instanceof Class)) {
return Object.class;
} return (Class) params[index];
} /**
* 通过反射, 获得 Class 定义中声明的父类的泛型参数类型 如: public EmployeeDao extends
* BaseDao<Employee, String>
*
* @param <T>
* @param clazz
* @return
*/
@SuppressWarnings("unchecked")
public static <T> Class<T> getSuperGenericType(Class clazz) {
return getSuperClassGenricType(clazz, 0);
} /**
* 循环向上转型, 获取对象的 DeclaredMethod
*
* @param object
* @param methodName
* @param parameterTypes
* @return
*/
public static Method getDeclaredMethod(Object object, String methodName,
Class<?>[] parameterTypes) { for (Class<?> superClass = object.getClass(); superClass != Object.class; superClass = superClass
.getSuperclass()) {
try {
// superClass.getMethod(methodName, parameterTypes);
return superClass.getDeclaredMethod(methodName, parameterTypes);
} catch (NoSuchMethodException e) {
// Method 不在当前类定义, 继续向上转型
}
// ..
} return null;
} /**
* 使 filed 变为可访问
*
* @param field
*/
public static void makeAccessible(Field field) {
if (!Modifier.isPublic(field.getModifiers())) {
field.setAccessible(true);
}
} /**
* 循环向上转型, 获取对象的 DeclaredField
*
* @param object
* @param filedName
* @return
*/
public static Field getDeclaredField(Object object, String filedName) { for (Class<?> superClass = object.getClass(); superClass != Object.class; superClass = superClass
.getSuperclass()) {
try {
return superClass.getDeclaredField(filedName);
} catch (NoSuchFieldException e) {
// Field 不在当前类定义, 继续向上转型
}
}
return null;
} /**
* 直接调用对象方法, 而忽略修饰符(private, protected)
*
* @param object
* @param methodName
* @param parameterTypes
* @param parameters
* @return
* @throws InvocationTargetException
* @throws IllegalArgumentException
*/
public static Object invokeMethod(Object object, String methodName,
Class<?>[] parameterTypes, Object[] parameters)
throws InvocationTargetException { Method method = getDeclaredMethod(object, methodName, parameterTypes); if (method == null) {
throw new IllegalArgumentException("Could not find method ["
+ methodName + "] on target [" + object + "]");
} method.setAccessible(true); try {
return method.invoke(object, parameters);
} catch (IllegalAccessException e) {
System.out.println("不可能抛出的异常");
} return null;
} /**
* 直接设置对象属性值, 忽略 private/protected 修饰符, 也不经过 setter
*
* @param object
* @param fieldName
* @param value
*/
public static void setFieldValue(Object object, String fieldName,
Object value) {
Field field = getDeclaredField(object, fieldName); if (field == null)
throw new IllegalArgumentException("Could not find field ["
+ fieldName + "] on target [" + object + "]"); makeAccessible(field); try {
field.set(object, value);
} catch (IllegalAccessException e) {
System.out.println("不可能抛出的异常");
}
} /**
* 直接读取对象的属性值, 忽略 private/protected 修饰符, 也不经过 getter
*
* @param object
* @param fieldName
* @return
*/
public static Object getFieldValue(Object object, String fieldName) {
Field field = getDeclaredField(object, fieldName); if (field == null)
throw new IllegalArgumentException("Could not find field ["
+ fieldName + "] on target [" + object + "]"); makeAccessible(field); Object result = null; try {
result = field.get(object);
} catch (IllegalAccessException e) {
System.out.println("不可能抛出的异常");
} return result;
}
}

反射工具类:ReflectionUtils.java 也可通过它代替BeanUtils的setProperty()给对象赋值然后返回该对象

2、获取数据库中的一些元数据:

    @Test
public void testDatebaseMetaData() throws Exception {
Connection conn = null;
ResultSet rs = null;
try {
conn = JDBCTools.getConnection();
DatabaseMetaData dbmd = conn.getMetaData();
// 得到数据库的一些基本信息
int version = dbmd.getDatabaseMajorVersion();
System.out.println(version);
String user = dbmd.getUserName();
System.out.println(user);
rs = dbmd.getCatalogs();
while (rs.next()) {
String str = rs.getString(1);
System.out.println(str);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCTools.release(rs, null, conn);
}
}

通过DatabaseMetaData dbmd = conn.getMetaData();获取

3、获取插入记录的主键值,在加入购物车时用到:

    @Test
public void testPrimeryKey() throws Exception {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "insert into customer(name,email,birth) values(?,?,?) "; try {
conn = JDBCTools.getConnection();
ps = conn.prepareStatement(sql, ps.RETURN_GENERATED_KEYS);
ps.setString(1, "BBBB");
ps.setString(2, "BBBB@163.COM");
ps.setDate(3, new Date(new java.util.Date().getTime()));
ps.executeUpdate();
rs = ps.getGeneratedKeys();
if (rs.next()) {
Object obj = rs.getObject(1);
System.out.println(obj);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCTools.release(null, ps, conn);
}
}

获取最新插入记录的主键值

4、读取 blob 数据:
 1. 使用 getBlob 方法读取到 Blob 对象
 2. 调用 Blob 的 getBinaryStream() 方法得到输入流。再使用 IO 操作即可.

@Test
public void readBlob(){
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null; try {
connection = JDBCTools.getConnection();
String sql = "SELECT id, name customerName, email, birth, picture "
+ "FROM customers WHERE id = 13";
preparedStatement = connection.prepareStatement(sql);
resultSet = preparedStatement.executeQuery(); if(resultSet.next()){
int id = resultSet.getInt(1);
String name = resultSet.getString(2);
String email = resultSet.getString(3); System.out.println(id + ", " + name + ", " + email);
Blob picture = resultSet.getBlob(5); InputStream in = picture.getBinaryStream();
System.out.println(in.available()); OutputStream out = new FileOutputStream("flower.jpg"); byte [] buffer = new byte[1024];
int len = 0;
while((len = in.read(buffer)) != -1){
out.write(buffer, 0, len);
} in.close();
out.close();
} } catch (Exception e) {
e.printStackTrace();
} finally{
JDBCTools.releaseDB(resultSet, preparedStatement, connection);
}
}

读取Blob数据(如图片)

5、事务:

•  事务:指构成单个逻辑工作单元的操作集合
•  事务处理:保证所有事务都作为一个工作单元来执行,即使出现了故障,都不能改变这种执行方式。当在一个事务中执行多个操作时,要么所有的事务都被提交(commit),要么整个事务回滚(rollback)到最初状态
•  当一个连接对象被创建时,默认情况下是自动提交事务:每次执行一个 SQL 语句时,如果执行成功,就会向数据库自动提交,而不能回滚
•  为了让多个 SQL 语句作为一个事务执行:
––调用 Connection 对象的 setAutoCommit(false); 以取消自动提交事务
––在所有的 SQL 语句都成功执行后,调用 commit(); 方法提交事务
––在出现异常时,调用 rollback(); 方法回滚事务
––若此时 Connection 没有被关闭, 则需要恢复其自动提交状态。
数据库的隔离级别:
•  对于同时运行的多个事务, 当这些事务访问数据库中相同的数据时, 如果没有采取必要的隔离机制,
   就会导致各种并发问题:
–––脏读: 对于两个事物 T1, T2, T1 读取了已经被 T2 更新但还没有被提交的字段. 之后, 若 T2 回滚,
             T1读取的内容就是临时且无效的.
–––不可重复读: 对于两个事物 T1, T2, T1 读取了一个字段, 然后 T2 更新了该字段. 
                     之后,T1再次读取同一个字段, 值就不同了.
–––幻读: 对于两个事物 T1, T2, T1 从一个表中读取了一个字段, 然后 T2 在该表中插入了一些新的行.  
             之后, 如果 T1 再次读取同一个表, 就会多出几行.
•  数据库事务的隔离性: 数据库系统必须具有隔离并发运行各个事务的能力, 使它们不会相互影响,
    避免各种并发问题.
•  一个事务与其他事务隔离的程度称为隔离级别. 数据库规定了多种事务隔离级别, 不同隔离级别对应不同的
   干扰程度,隔离级别越高, 数据一致性就越好, 但并发性越弱.
java攻城狮之路--复习JDBC(利用BeanUtils、JDBC元数据编写通用的查询方法;元数据;Blob;事务;批量处理)
•  Oracle 支持的 2 种事务隔离级别:READ COMMITED, SERIALIZABLE,Oracle 默认的事务隔离级别为:
    READ COMMITED。
•  Mysql 支持 4 中事务隔离级别. Mysql 默认的事务隔离级别为: REPEATABLE READ。
在 MySql 中设置隔离级别:
•  每启动一个 mysql 程序, 就会获得一个单独的数据库连接. 每个数据库连接都有一个全局变量
   @@tx_isolation, 表示当前的事务隔离级别. MySQL 默认的隔离级别为 Repeatable Read
•  查看当前的隔离级别: SELECT @@tx_isolation;
•  设置当前 mySQL 连接的隔离级别: 
    –set  transaction isolation level read committed;
•  设置数据库系统的全局的隔离级别:
    –set global transaction isolation level read committed;

关于事务:
1. 如果多个操作, 每个操作使用的是自己的单独的连接, 则无法保证事务.
2. 具体步骤: 1). 事务操作开始前, 开始事务:取消Connection 的默认提交行为. connection.setAutoCommit(false).
2). 如果事务的操作都成功,则提交事务: connection.commit();
3). 回滚事务: 若出现异常, 则在 catch 块中回滚事务:connection.rollback();

    @Test
public void testTransaction() { Connection connection = null; try { connection = JDBCTools.getConnection();
System.out.println(connection.getAutoCommit()); // 开始事务: 取消默认提交.
connection.setAutoCommit(false); String sql = "UPDATE users SET balance = "
+ "balance - 500 WHERE id = 1";
update(connection, sql); int i = 10 / 0;
System.out.println(i); sql = "UPDATE users SET balance = " + "balance + 500 WHERE id = 2";
update(connection, sql); // 提交事务
connection.commit();
} catch (Exception e) {
e.printStackTrace(); // 回滚事务
try {
connection.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}
} finally {
JDBCTools.releaseDB(null, null, connection);
} /*
* try {
*
* //开始事务: 取消默认提交. connection.setAutoCommit(false);
*
* //...
*
* //提交事务 connection.commit(); } catch (Exception e) { //...
*
* //回滚事务 try { connection.rollback(); } catch (SQLException e1) {
* e1.printStackTrace(); } } finally{ JDBCTools.releaseDB(null, null,
* connection); }
*/ // DAO dao = new DAO();
//
// String sql = "UPDATE users SET balance = " +
// "balance - 500 WHERE id = 1";
// dao.update(sql);
//
// int i = 10 / 0;
// System.out.println(i);
//
// sql = "UPDATE users SET balance = " +
// "balance + 500 WHERE id = 2";
// dao.update(sql); }

事务测试例子

    @Test
public void testTransactionIsolationRead() {
String sql = "SELECT balance FROM users WHERE id = 1";
Integer balance = getForValue(sql);
System.out.println(balance);
} // 返回某条记录的某一个字段的值 或 一个统计的值(一共有多少条记录等.)
public <E> E getForValue(String sql, Object... args) { // 1. 得到结果集: 该结果集应该只有一行, 且只有一列
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null; try {
// 1. 得到结果集
connection = JDBCTools.getConnection();
System.out.println(connection.getTransactionIsolation()); // connection.setTransactionIsolation(Connection.TRANSACTION_READ_UNCOMMITTED);
connection.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED); preparedStatement = connection.prepareStatement(sql); for (int i = 0; i < args.length; i++) {
preparedStatement.setObject(i + 1, args[i]);
} resultSet = preparedStatement.executeQuery(); if (resultSet.next()) {
return (E) resultSet.getObject(1);
}
} catch (Exception ex) {
ex.printStackTrace();
} finally {
JDBCTools.releaseDB(resultSet, preparedStatement, connection);
}
// 2. 取得结果 return null;
}

事务的隔离级别:在 JDBC 程序中可以通过 Connection 的 setTransactionIsolation 来设置事务的隔离级别

6、批量处理JDBC语句提高处理速度:

•  当需要成批插入或者更新记录时。可以采用Java的批量更新机制,
   这一机制允许多条语句一次性提交给数据库批量处理。通常情况下比单独提交处理更有效率
•  JDBC的批量处理语句包括下面两个方法:
   –addBatch(String):添加需要批量处理的SQL语句或是参数;
   –executeBatch(): 执行批量处理语句;
•  通常我们会遇到两种批量执行SQL语句的情况:
   – 多条SQL语句的批量处理;
   – 一个SQL语句的批量传参;

java攻城狮之路--复习JDBC(利用BeanUtils、JDBC元数据编写通用的查询方法;元数据;Blob;事务;批量处理)

java攻城狮之路--复习JDBC(利用BeanUtils、JDBC元数据编写通用的查询方法;元数据;Blob;事务;批量处理)

    @Test
public void testBatch(){
Connection connection = null;
PreparedStatement preparedStatement = null;
String sql = null; try {
connection = JDBCTools.getConnection();
JDBCTools.beginTx(connection);
sql = "INSERT INTO customers VALUES(?,?,?)";
preparedStatement = connection.prepareStatement(sql);
Date date = new Date(new java.util.Date().getTime()); long begin = System.currentTimeMillis();
for(int i = 0; i < 100000; i++){
preparedStatement.setInt(1, i + 1);
preparedStatement.setString(2, "name_" + i);
preparedStatement.setDate(3, date); //"积攒" SQL
preparedStatement.addBatch(); //当 "积攒" 到一定程度, 就统一的执行一次. 并且清空先前 "积攒" 的 SQL
if((i + 1) % 300 == 0){
preparedStatement.executeBatch();
preparedStatement.clearBatch();
}
} //若总条数不是批量数值的整数倍, 则还需要再额外的执行一次.
if(100000 % 300 != 0){
preparedStatement.executeBatch();
preparedStatement.clearBatch();
} long end = System.currentTimeMillis(); System.out.println("Time: " + (end - begin)); // JDBCTools.commit(connection);
} catch (Exception e) {
e.printStackTrace();
JDBCTools.rollback(connection);
} finally{
JDBCTools.releaseDB(null, preparedStatement, connection);
}
} @Test
public void testBatchWithPreparedStatement(){
Connection connection = null;
PreparedStatement preparedStatement = null;
String sql = null; try {
connection = JDBCTools.getConnection();
JDBCTools.beginTx(connection);
sql = "INSERT INTO customers VALUES(?,?,?)";
preparedStatement = connection.prepareStatement(sql);
Date date = new Date(new java.util.Date().getTime()); long begin = System.currentTimeMillis();
for(int i = 0; i < 100000; i++){
preparedStatement.setInt(1, i + 1);
preparedStatement.setString(2, "name_" + i);
preparedStatement.setDate(3, date); preparedStatement.executeUpdate();
}
long end = System.currentTimeMillis(); System.out.println("Time: " + (end - begin)); // JDBCTools.commit(connection);
} catch (Exception e) {
e.printStackTrace();
JDBCTools.rollback(connection);
} finally{
JDBCTools.releaseDB(null, preparedStatement, connection);
}
} /**
* 向 Oracle 的 customers 数据表中插入 10 万条记录
* 测试如何插入, 用时最短.
* 1. 使用 Statement.
*/
@Test
public void testBatchWithStatement(){
Connection connection = null;
Statement statement = null;
String sql = null; try {
connection = JDBCTools.getConnection();
JDBCTools.beginTx(connection); statement = connection.createStatement(); long begin = System.currentTimeMillis();
for(int i = 0; i < 100000; i++){
sql = "INSERT INTO customers VALUES(" + (i + 1)
+ ", 'name_" + i + "', '29-6月 -13')";
statement.addBatch(sql);
}
long end = System.currentTimeMillis(); System.out.println("Time: " + (end - begin)); // JDBCTools.commit(connection);
} catch (Exception e) {
e.printStackTrace();
JDBCTools.rollback(connection);
} finally{
JDBCTools.releaseDB(null, statement, connection);
}
}

批量处理测试例子