Common?Dbutils是操作數據庫的組件，對傳統操作數據庫的類進行二 次封裝，可以把結果集轉化成List。


DBUtils包括3個包：
org.apache.commons.dbutils?
org.apache.commons.dbutils.handlers?
org.apache.commons.dbutils.wrappers
DBUtils封裝了對JDBC的操作，簡化了JDBC操作，可以少寫代碼。
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org.apache.commons.dbutils
DbUtils?關閉鏈接等操作
QueryRunner?進行查詢的操作
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org.apache.commons.dbutils.handlers
ArrayHandler?：將ResultSet中第一行的數據轉化成對象數組
ArrayListHandler將ResultSet中所有的數據轉化成List，List中存放的是 Object[]
BeanHandler?：將ResultSet中第一行的數據轉化成類對象
BeanListHandler?：將ResultSet中所有的數據轉化成List，List中存放的是類對象
ColumnListHandler?：將ResultSet中某一列的數據存成List，List中存放的是 Object對象
KeyedHandler?：將ResultSet中存成映射，key為某一列對應為Map。Map中存放的是數 據
MapHandler?：將ResultSet中第一行的數據存成Map映射
MapListHandler?：將ResultSet中所有的數據存成List。List中存放的是Map
ScalarHandler?：將ResultSet中一條記錄的其中某一列的數據存成Object
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org.apache.commons.dbutils.wrappers
SqlNullCheckedResultSet?：對ResultSet進行操作，改版里面的值
StringTrimmedResultSet?：去除ResultSet中中字段的左右空格。Trim()
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主要方法：

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DbUtils類：啟動類

ResultSetHandler接口：轉換類型接口

MapListHandler類：實現類，把記錄轉化成List

BeanListHandler類：實現類，把記錄轉化成List，使記錄為JavaBean類型的對象

Qrery?Runner類：執行SQL語句的類

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建立三個Java文件

命名為BeanListExample.java

Guestbook.java

MapListExample.java
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源碼：

BeanListExample.java

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Code
package ?com.sy;

import ?org.apache.commons.dbutils.DbUtils;
import ?org.apache.commons.dbutils.QueryRunner;
import ?org.apache.commons.dbutils.handlers.BeanListHandler;
import ?java.sql.Connection;
import ?java.sql.DriverManager;
import ?java.sql.SQLException;
import ?java.util.List;

public ? class ?BeanListExample? {
???? public ? static ? void ?main(String[]?args)? {
????????Connection?conn? = ? null ;
????????String?url? = ? " jdbc:mysql://localhost:3306/people " ;
????????String?jdbcDriver? = ? " com.mysql.jdbc.Driver " ;
????????String?user? = ? " root " ;
????????String?password? = ? " hicc " ;

????????DbUtils.loadDriver(jdbcDriver);
???????? try ? {
????????????conn? = ?DriverManager.getConnection(url,?user,?password);
????????????QueryRunner?qr? = ? new ?QueryRunner();
????????????List?results? = ?(List)?qr.query(conn,? " select?id,name?from?guestbook " ,? new ?BeanListHandler(Guestbook. class ));
???????????? for ?( int ?i? = ? 0 ;?i? < ?results.size();?i ++ )? {
????????????????Guestbook?gb? = ?(Guestbook)?results.get(i);
????????????????System.out.println( " id: " ? + ?gb.getId()? + ? " ,name: " ? + ?gb.getName());
????????????}
????????} ? catch ?(SQLException?e)? {
????????????e.printStackTrace();
????????} ? finally ? {
????????????DbUtils.closeQuietly(conn);
????????}
????}
}
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Guestbook.java

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Code
package ?com.sy;

public ? class ?Guestbook? {
???? private ?Integer?id;
???? private ?String?name;

???? 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;
????}
}
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MapListExample.java

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Code
package ?com.sy;

import ?org.apache.commons.dbutils.DbUtils;
import ?org.apache.commons.dbutils.QueryRunner;
import ?org.apache.commons.dbutils.handlers.MapListHandler;

import ?java.sql.Connection;
import ?java.sql.DriverManager;
import ?java.sql.SQLException;

import ?java.util.List;
import ?java.util.Map;

public ? class ?MapListExample? {
???? public ? static ? void ?main(String[]?args)? {
????????Connection?conn? = ? null ;
????????String?url? = ? " jdbc:mysql://localhost:3306/people " ;
????????String?jdbcDriver? = ? " com.mysql.jdbc.Driver " ;
????????String?user? = ? " root " ;
????????String?password? = ? " hicc " ;

????????DbUtils.loadDriver(jdbcDriver);
???????? try ? {
????????????conn? = ?DriverManager.getConnection(url,?user,?password);
????????????QueryRunner?qr? = ? new ?QueryRunner();
????????????List?results? = ?(List)?qr.query(conn,? " select?id,name?from?guestmessage " ,? new ?MapListHandler());
???????????? for ?( int ?i? = ? 0 ;?i? < ?results.size();?i ++ )? {
????????????????Map?map? = ?(Map)?results.get(i);
????????????????System.out.println( " id: " ? + ?map.get( " id " )? + ? " ,name: " ? + ?map.get( " name " ));
????????????}
????????} ? catch ?(SQLException?e)? {
????????????e.printStackTrace();
????????} ? finally ? {
????????????DbUtils.closeQuietly(conn);
????????}
????}
}
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使用組建好需要添加commons - dbutils - 1.1 .jar和mysql - connector - java - 5.1 . 6 - bin.jar 兩個jar包。

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配置完畢！！！

? // 另一種方法
// 使用dbutils1.0版本

import ?java.util. * ;
import ?java.util.logging. * ;
import ?java.sql. * ;
import ?org.apache.commons.dbutils. * ;
import ?org.apache.commons.dbutils.handlers. * ;

public ? class ?TestDBUnits? {
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? public ? static ? void ?main(String[]args)? throws ?Exception? {
??TestDBUnits?test? = ? new ?TestDBUnits();
??
?? for ( int ?i? = ? 0 ?;?i? < ? 1 ?;?i ++ )? {???
???test.testQuery1();
???test.testQuery2();
???test.testUpdate();
??}
?}
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? public ? void ?testQuery1() {
?? try ? {
???QueryRunner?qr? = ? new ?QueryRunner()?;
???ResultSetHandler?rsh? = ? new ?ArrayListHandler();???
???String?strsql? = ? " select?*?from?test1 " ;???
???ArrayList?result? = ?(ArrayList)qr.query(getConnection()?,strsql?,rsh);
??? // System.out.print("");
??} ? catch (Exception?ex)? {
???ex.printStackTrace(System.out);
??}
?}
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? public ? void ?testQuery2() {
?? try ? {
???QueryRunner?qr? = ? new ?QueryRunner()?;
???ResultSetHandler?rsh? = ? new ?MapListHandler();???
???String?strsql? = ? " select?*?from?test1 " ;???
???ArrayList?result? = ?(ArrayList)qr.query(getConnection()?,strsql?,rsh);
??? for ( int ?i? = ? 0 ?;?i? < ?result.size()?;?i ++ )? {
????Map?map? = ?(Map)result.get(i);
???? // System.out.println(map);????
???}
??? // System.out.print("");
??} ? catch (Exception?ex)? {
???ex.printStackTrace(System.out);
??}
?}
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? public ? void ?testUpdate() {
?? try ? {
???QueryRunner?qr? = ? new ?QueryRunner()?;
???ResultSetHandler?rsh? = ? new ?ArrayListHandler();
???String?strsql? = ? " insert?test1(page?,writable?,content)values('ttt','ttt','faskldfjklasdjklfjasdklj') " ;
???qr.update(getConnection()?,strsql);
??? // System.out.print("");
??} ? catch (Exception?ex)? {
???ex.printStackTrace(System.out);
??}
?}
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? private ??Connection?getConnection()? throws ?InstantiationException,
???IllegalAccessException,?ClassNotFoundException,?SQLException? {
??
??String?strDriver? = ? " org.gjt.mm.mysql.Driver " ;
??String?strUrl? = ? " jdbc:mysql://localhost:3306/test " ;
??String?strUser? = ? " root " ;
??String?strPass? = ? "" ;
???
??Class.forName(strDriver).newInstance();??
?? return ?DriverManager.getConnection(strUrl,?strUser,?strPass);
?}
}