DBUtils 使用小结
Apache DBUtils 是一款轻量级的Java ORM框架，可以有效的提高JDBC的操作效率，目前官方最新版本 1.6。
官网地址：http://commons.apache.org/proper/commons-dbutils/
这里跟大家分享DBUtils的一些基本用法以及自己总结的一个基于DBUtils 封装的JDBC CRUD工具类，这里使用的DBUtils版本为 1.6，数据源为 c3p0，Log4j管理系统日志。
数据库表结构如下：
CREATE DATABASE test DEFAULT charset utf8;//建库
CREATE TABLE t_user(
id int(11) NOT NULL AUTO_INCREMENT,
name varchar(128) NOT NULL,
nickName varchar(128) DEFAULT NULL,
password varchar(128) NOT NULL,
age int(3) unsigned default 0,
height float(3,2) unsigned default 0,
PRIMARY KEY('id'),
UNIQUE KEY('name')
) engine=MyISAM default charset=utf8 COLLATE=utf8_bin;整个项目目录结构如下图所示：
实体类User
package com.ricky.java.db.test.model;
public class User {
private long id;
private String name;
private String nickName;
private String password;
private int age;
private float height;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getNickName() {
return nickName;
}
public void setNickName(String nickName) {
this.nickName = nickName;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public float getHeight() {
return height;
}
public void setHeight(float height) {
this.height = height;
}
}
DBUtilsDAO.java
package com.ricky.java.db.test;
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 org.apache.commons.dbutils.handlers.ScalarHandler;
import com.ricky.java.db.DataSourceManager;
import com.ricky.java.db.test.model.User;
/**
* use DBUtils CRUD Demo
* @author Ricky Feng
* @version 2014-09-03 23:10
*
*/
public class DBUtilsDAO {
QueryRunner qr = new QueryRunner(DataSourceManager.getInstance().getDataSource());
public long insert(User user){
try {
String sql = "INSERT INTO t_user (name,nickName,password,age,height) VALUES (?,?,?,?,?)";
Object[] params = new Object[]{user.getName(),user.getNickName(),user.getPassword()
,user.getAge(),user.getHeight()};
//Execute the SQL update statement and return the number of inserts that were made
// int inserts = qr.update(sql, params);
//
// return inserts;
//return AUTO_INCREMENT id
long id = qr.insert(sql, new ScalarHandler(), params);
return id;
} catch (SQLException e) {
e.printStackTrace();
}
return 0;
}
public int[] batch(List userList){
try {
String sql = "INSERT INTO t_user (name,nickName,password,age,height) VALUES (?,?,?,?,?)";
Object[][] params = new Object[userList.size()][]; //二维数组
for(int i=0;i(User.class), new Object[]{name});
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
public List queryAll(){
try {
String sql = "SELECT * FROM t_user";
return qr.query(sql, new BeanListHandler(User.class));
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
public long count(){
try {
String sql = "SELECT COUNT(*) as count FROM t_user";
return qr.query(sql, new ScalarHandler());
} catch (SQLException e) {
e.printStackTrace();
}
return 0;
}
}
使用DBUtils操作数据库非常方便，省去了很多重复代码。
虽然DBUtils已经帮我们做了很多工作，但是个人感觉还不够，例如：每次操作都要获取数据源，每次拼SQL语句等等，这些都是通用的，可以封装起来，于是乎有了 BaseDAO，示例代码如下：
package com.ricky.java.db.dao;
import java.sql.SQLException;
import java.util.Arrays;
import java.util.List;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.apache.log4j.Logger;
import com.ricky.java.db.DataSourceManager;
/**
* Generic CRUD Operation Interface
*
* @author Ricky Feng
* @version 2014-09-03 23:30
*
* @param
*/
public abstract class BaseDAO {
protected final Logger mLogger = Logger.getLogger("devLog");
protected QueryRunner qr = new QueryRunner(DataSourceManager.getInstance()
.getDataSource());
//return AUTO_INCREMENT id
public long insert(String[] columns, ScalarHandler rsh,
Object... params) throws SQLException {
String sql = "INSERT INTO " + getTableName() + " ("
+ getColumnsName(columns) + ") VALUES ("
+ getColumnsValue(columns) + ")";
mLogger.debug("BaseDAO insert sql=" + sql + "**params="
+ Arrays.toString(params));
// return qr.update(sql, params);
return qr.insert(sql, rsh, params);
}
public int insert(String[] columns,
Object... params) throws SQLException {
String sql = "INSERT INTO " + getTableName() + " ("
+ getColumnsName(columns) + ") VALUES ("
+ getColumnsValue(columns) + ")";
mLogger.debug("BaseDAO insert sql=" + sql + "**params="
+ Arrays.toString(params));
return qr.update(sql, params);
}
public int delete(String whereClause, Object[] whereArgs)
throws SQLException {
String sql = "delete from " + getTableName() + " where " + whereClause;
mLogger.debug("BaseDAO delete sql=" + sql + "**params="
+ Arrays.toString(whereArgs));
return qr.update(sql, whereArgs);
}
public int update(String[] updateColumns, String whereClause,
Object[] params) throws SQLException {
String sql = "UPDATE " + getTableName() + " SET "
+ getUpdateColumns(updateColumns) + " WHERE " + whereClause;
mLogger.debug("BaseDAO update sql=" + sql + "**params="
+ Arrays.toString(params));
return qr.update(sql, params);
}
public T query(String[] columns, String selection, ResultSetHandler rsh,
Object[] selectionArgs) throws SQLException {
String sql = "SELECT " + getColumnsName(columns) + " FROM "
+ getTableName() + " WHERE " + selection;
mLogger.debug("BaseDAO query sql=" + sql + "**params="
+ Arrays.toString(selectionArgs));
return qr.query(sql, rsh, selectionArgs);
}
public List queryAll(String[] columns, String selection,
BeanListHandler rsh, Object[] selectionArgs, String orderBy)
throws SQLException {
String whereClause = " ";
if (selection != null && selection.length() > 0) {
whereClause = " WHERE " + selection;
}
String sql = "SELECT " + getColumnsName(columns) + " FROM "
+ getTableName() + whereClause + " ORDER BY " + orderBy;
mLogger.debug("BaseDAO queryAll sql=" + sql + "**params="
+ Arrays.toString(selectionArgs));
return qr.query(sql, rsh, selectionArgs);
}
public List queryAll(String[] columns, String selection,
BeanListHandler rsh, Object[] selectionArgs, String orderBy,
int offset, int size) throws SQLException {
String whereClause = " ";
if (selection != null && selection.length() > 0) {
whereClause = " WHERE " + selection;
}
String sql = "SELECT " + getColumnsName(columns) + " FROM "
+ getTableName() + whereClause + " ORDER BY " + orderBy
+ " limit " + offset + "," + size;
mLogger.debug("BaseDAO queryAll limit sql=" + sql + "**params="
+ Arrays.toString(selectionArgs));
return qr.query(sql, rsh, selectionArgs);
}
public boolean find(String selection, ResultSetHandler rsh,
Object[] selectionArgs) throws SQLException {
String sql = "SELECT * FROM " + getTableName() + " WHERE " + selection;
mLogger.debug("BaseDAO find sql=" + sql + "**params="
+ Arrays.toString(selectionArgs));
return qr.query(sql, rsh, selectionArgs) != null;
}
public long count(String selection, Object[] selectionArgs)
throws SQLException {
String whereClause = " ";
if (selection != null && selection.length() > 0) {
whereClause = " WHERE " + selection;
}
String sql = "SELECT COUNT(*) as count FROM " + getTableName()
+ whereClause;
mLogger.debug("BaseDAO count sql=" + sql + "**params="
+ Arrays.toString(selectionArgs));
return qr.query(sql, new ScalarHandler());
}
public abstract String getTableName();
public String getUpdateColumns(String[] columns) {
if (columns == null || columns.length < 1) {
throw new NullPointerException("getColumnsValue columns is empty");
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < columns.length; i++) {
sb.append(columns[i]).append("=?");
if (i != columns.length - 1) {
sb.append(",");
}
}
return sb.toString();
}
public String getColumnsName(String[] columns) {
if (columns == null || columns.length < 1) {
throw new NullPointerException("getColumnsValue columns is empty");
}
if ("*".equals(columns[0])) {
return "*";
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < columns.length; i++) {
sb.append(columns[i]);
if (i != columns.length - 1) {
sb.append(",");
}
}
return sb.toString();
}
public String getColumnsValue(String[] columns) {
if (columns == null || columns.length < 1) {
throw new NullPointerException("getColumnsValue columns is empty");
}
if ("*".equals(columns[0])) {
return "*";
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < columns.length; i++) {
sb.append("?");
if (i != columns.length - 1) {
sb.append(",");
}
}
return sb.toString();
}
}
有了BaseDAO之后，再写DAO就非常简单了，这里以t_user表为例，实现对User对象的CRUD操作。
UserDAO.java
package com.ricky.java.db.test.dao;
import com.ricky.java.db.dao.BaseDAO;
import com.ricky.java.db.test.model.User;
/**
* DAO Demo
* @author Ricky Feng
* @version 2014-09-03 23:45
*
*/
public class UserDAO extends BaseDAO{
@Override
public String getTableName() {
return "t_user";
}
}
DAO业务逻辑接口 UserDAOBiz.java
package com.ricky.java.db.test.dao.biz;
import java.util.List;
import com.ricky.java.db.test.model.User;
/**
* Define User CRUD OP
* @author Ricky Feng
* @version 2014-09-03 23:47
*
*/
public interface UserDAOBiz {
public long insert(User user);
public int update(User user);
public int delete(String name);
public List getUserList();
}
DAO业务逻辑实现类 UserDAOBizImpl.java
package com.ricky.java.db.test.dao.biz;
import java.sql.SQLException;
import java.util.List;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.apache.log4j.Logger;
import com.ricky.java.db.test.dao.UserDAO;
import com.ricky.java.db.test.model.User;
/**
* DAO Biz Demo
* @author Ricky Feng
* @version 2014-09-03 23:48
*
*/
public class UserDAOBizImpl implements UserDAOBiz {
protected final Logger mLogger = Logger.getLogger("devLog");
private UserDAO userDAO = new UserDAO();
private String[] columns = new String[]{"name","nickName","password","age","height"};
@Override
public long insert(User user) {
try {
Object[] params = new Object[]{user.getName(),user.getNickName(),user.getPassword()
,user.getAge(),user.getHeight()};
return userDAO.insert(columns, new ScalarHandler(), params);
} catch (SQLException e) {
e.printStackTrace();
mLogger.error("UserDAOBizImpl insert SQLException",e);
}
return 0;
}
@Override
public int update(User user) {
try {
Object[] params = new Object[]{user.getName(),user.getNickName(),user.getPassword()
,user.getAge(),user.getHeight(),user.getName()};
return userDAO.update(columns, "name=?", params);
} catch (SQLException e) {
e.printStackTrace();
mLogger.error("UserDAOBizImpl update SQLException",e);
}
return 0;
}
@Override
public int delete(String name) {
try {
return userDAO.delete("name=?", new Object[]{name});
} catch (SQLException e) {
e.printStackTrace();
mLogger.error("UserDAOBizImpl delete SQLException",e);
}
return 0;
}
@Override
public List getUserList() {
try {
return userDAO.queryAll(columns, null, new BeanListHandler(User.class), null, "id ASC");
} catch (SQLException e) {
e.printStackTrace();
mLogger.error("UserDAOBizImpl getUserList SQLException",e);
}
return null;
}
}
OK，到这里整个DAO相关逻辑就写完了，最后是测试代码
package com.ricky.java.db.test;
import com.ricky.java.db.test.dao.DBUtilsDAO;
import com.ricky.java.db.test.dao.biz.UserDAOBiz;
import com.ricky.java.db.test.dao.biz.UserDAOBizImpl;
import com.ricky.java.db.test.model.User;
public class DBTest {
/**
* @param args
*/
public static void main(String[] args) {
//1.普通DAO
DBUtilsDAO dbUtilsDAO = new DBUtilsDAO();
User user = new User();
user.setName("Ricky");
user.setPassword("ricky");
user.setAge(25);
user.setHeight(1.80f);
dbUtilsDAO.insert(user);
//2.使用模板DAO
UserDAOBiz userDAOBiz = new UserDAOBizImpl();
userDAOBiz.insert(user);
}
}
一个简单的JDBC 工具类就完成了，欢迎大家拍砖！
不早了，该洗洗睡了，晚安，北京！
源码下载地址：http://download.csdn.net/detail/fx_sky/7861253