apache DBUtils 使用例子demo
apache DBUtils是java编程中的数据库操作实用工具，小巧简单实用，
1.对于数据表的读操作，他可以把结果转换成List，Array，Set等java集合，便于程序员操作；
2.对于数据表的写操作，也变得很简单（只需写sql语句）
3.可以使用数据源，使用JNDI， 数据库连接池等技术来优化性能--重用已经构建好的数据库连接对象，而不像php，asp那样，费时费力的不断重复的构建和析构这样的对象。
DBUtils包括3个包：
org.apache.commons.dbutils
org.apache.commons.dbutils.handlers
org.apache.commons.dbutils.wrappers
DBUtils封装了对JDBC的操作，简化了JDBC操作，可以少写代码。
org.apache.commons.dbutils
DbUtils 关闭链接等操作
QueryRunner 进行查询的操作
org.apache.commons.dbutils.handlers
ArrayHandler ：将ResultSet中第一行的数据转化成 对象数组
ArrayListHandler将ResultSet中所有的数据转化成List，List中存放的是Object[]
BeanHandler ：将ResultSet中第一行的数据转化成类对象
BeanListHandler ：将ResultSet中所有的数据转化成List，List中存放的是类对象
ColumnListHandler ：将ResultSet中某一列的数据存成List，List中存放的是Object对象
KeyedHandler ：将ResultSet中存成映射，key为某一列对应为Map。Map中存放的是数据
MapHandler ：将ResultSet中第一行的数据存成Map映射
MapListHandler ：将ResultSet中所有的数据存成List。List中存放的是Map
ScalarHandler ：将ResultSet中一条记录的其中某一列的数据存成Object
org.apache.commons.dbutils.wrappers
SqlNullCheckedResultSet ：对ResultSet进行操作，改版里面的值
StringTrimmedResultSet ：去除ResultSet中中字段的左右空格。Trim()
主要方法：
DbUtils类：启动类
ResultSetHandler接口：转换类型接口
MapListHandler类：实现类，把记录转化成List
BeanListHandler类：实现类，把记录转化成List，使记录为JavaBean类型的对象
Qrery Runner类：执行SQL语句的类
http://commons.apache.org/proper/commons-dbutils/
Queryrunner.query —————只可以执行select语句。
Queryrunner.update —————只可以接收update,delte,insert语句
BeanHandler ——————返回一个 Bean，结果封装到Bean。只查询第一行。适合根据id查询唯一的一行
BeanListHandler ——————返回List所有行，都封装到List，适合于查询多个结果
MapHandler ——————与BeanHandler应，只返回第一行，封装成Map类型 － 也适合于查询一个结果集的 适合于关联查询，且没有匹配的Bean。
MapListHandler ——————与BeanListHandler对应，返回所有，封装成List
ScalarHandler ——————标量- 用于select count(1)|sum|avg|max …一些聚合函数
package com.jiepu.testdbutil;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Date;
import java.util.List;
import java.util.Map;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.MapHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
import org.sqlite.SQLiteDataSource;
//http://www.cnblogs.com/liuwt365/p/4111584.html
public class TestDBUtils {
private static SQLiteDataSource dataSource;
private static QueryRunner runner;
private static String tableName="User";
@BeforeClass
public static void setUpBeforeClass() throws Exception {
dataSource= new SQLiteDataSource();
dataSource.setUrl("jdbc:sqlite:testdbutil.db");
runner=new QueryRunner(dataSource);
execute("CREATE TABLE IF NOT EXISTS "+tableName+"(id integer primary key autoincrement, name varchar(50),password varchar(50)," +
"age integer,createdate integer)",dataSource);
}
public static int execute(String sql ,SQLiteDataSource dataSource){
Statement statement;
int result =0;
try {
statement = dataSource.getConnection().createStatement();
result= statement.executeUpdate(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return result;
}
@Test
public void Query1() throws Exception
{
//String sql="INSERT INTO users VALUES ('U002','tom','4321' )";
//runner.update(sql);
String sql="INSERT INTO "+tableName+"(name,password,age,createdate) VALUES (?,?,?,?)";
runner.update(sql,"Jim","123456","24",new Date().getTime());
runner.update(sql,"Kim","1234567","24",new Date().getTime());
runner.update(sql,"北京","12345678","24",new Date().getTime());
runner.update(sql,"嘉兴","123456789","24",new Date().getTime());
runner.update(sql,"tom","123456789","24",new Date().getTime());
System.out.println(dataSource);
}
@Test
public void Query2() throws Exception
{
//String sql=" UPDATE users SET NAME='Kim' WHERE NAME='jim' ";
//runner.update(sql);
String sql=" UPDATE "+tableName+" SET name=? WHERE name=? ";
runner.update(sql,"lily","Kim");
Query5();
}
@Test
public void Query3() throws Exception
{
//String sql="DELETE FROM users WHERE NAME='lily' ";
//runner.update(sql);
String sql="DELETE FROM "+tableName+" WHERE name=? ";
runner.update(sql,"tom");
Query5();
}
@Test
public void Query4() throws Exception
{
//String sql="SELECT * FROM users where id ='U002' ";
//user u= runner.query(sql, new BeanHandler(user.class));
String sql="SELECT * FROM "+tableName+" where id =? ";
User u=runner.query(sql, new BeanHandler(User.class),"2");
System.out.println(u);
}
@Test
public void Query5() throws Exception
{
String sql="select * from "+tableName;
List list= runner.query(sql, new BeanListHandler(User.class));
for(User u:list)
{
System.out.println(u);
}
}
@Test
public void Query6() throws Exception
{
String sql="select id,name,password from "+tableName;
Map map= runner.query(sql, new MapHandler());
System.out.println(map.toString());
}
@Test
public void Query7() throws Exception
{
String sql="select id,name,password from "+tableName;
List> list= runner.query(sql, new MapListHandler());
System.out.println(list);
}
@Test
public void Query8() throws Exception
{
String sql="select count(*) from "+tableName;
Object obj=runner.query(sql, new ScalarHandler());
int i=Integer.valueOf(obj.toString());
System.out.println(i);
}
@Test
public void batch()
{
/**String sql="INSERT INTO "+tableName+"(name,password,age,createdate) VALUES (?,?,?,?)";
List users=new ArrayList();
users.add(new User());
runner.batch(sql, users.toArray());
Query5();*/
}
@Test
public void custom() throws SQLException
{
ResultSetHandler h = new ResultSetHandler() {
public User[] handle(ResultSet rs) throws SQLException {
if (!rs.next()) {
return null;
}
ResultSetMetaData meta = rs.getMetaData();
int cols = meta.getColumnCount();
User[] result = new User[cols];
for (int i = 0; i < cols; i++) {
User user=new User();
user.setId(rs.getInt(1));
user.setName(rs.getString(2));
user.setPassword(rs.getString(3));
user.setAge(rs.getLong(4));
user.setCreatedate(rs.getLong(5));
result[i]=user;
rs.next();
}
return result;
}
};
User[] result = runner.query("SELECT * FROM "+tableName+" WHERE age=?", h, "24");
for (User user : result) {
System.out.println(user);
}
}
//http://wenku.baidu.com/view/6d4bb27602768e9951e73849.html
@AfterClass
public static void setUpAfterclass()
{
dataSource=null;
runner=null;
}
}
package com.jiepu.testdbutil;
public class User {
//使用dbutil 实体类成员不要使用基本类型int long 应该使用封装类型 Integer Long
private Integer id;
private String name;
private String password;
private Long age;
private Long createdate;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Long getAge() {
return age;
}
public void setAge(Long age) {
this.age = age;
}
public Long getCreatedate() {
return createdate;
}
public void setCreatedate(Long createdate) {
this.createdate = createdate;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", password=" + password
+ ", age=" + age + ", createdate=" + createdate + "]";
}
}
4.0.0
com.jiepu
testdbutil
0.0.1-SNAPSHOT
jar
testdbutil
http://maven.apache.org
UTF-8
junit
junit
4.8.1
commons-dbutils
commons-dbutils
1.6
org.xerial
sqlite-jdbc
3.8.7