MySQL – iBatis – 文件存儲

 

把上傳的文件保存到數據庫中。數據庫的類型爲blob和longblob。上傳文件的大小大於1M是需要修改MySQL的my.ini配置文件。

修改內容如下：

 

[mysqld]
max_allowed_packet=1024M

實驗步驟：

一、創建數據庫表。

腳本：

 

DROP TABLE IF EXISTS `upload`;

CREATE TABLE `upload` (

`dir` varchar(100) NOT NULL DEFAULT '', /* 保存上傳的時間 */

`upload` longblob, /* 存儲文件 */

PRIMARY KEY (`dir`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8;

二、建立Java項目

三、添加MySQL數據庫驅動包

四、添加iBatis包

五、添加iBatis主配置文件

代碼：

 

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMapConfig
PUBLIC "-//ibatis.apache.org//DTD SQL Map Config 2.0//EN"
"http://ibatis.apache.org/dtd/sql-map-config-2.dtd">
<sqlMapConfig>
<transactionManager type="JDBC" commitRequired="false">
  <dataSource type="SIMPLE">
  <property name="JDBC.Driver"   value="com.mysql.jdbc.Driver"/>
<property name="JDBC.ConnectionURL" value="jdbc:mysql://10.32.52.19:3306/iBatis"/>
<property name="JDBC.Username" value="root"/>
<property name="JDBC.Password" value="root"/>
</dataSource>
</transactionManager>
<sqlMap resource="oks-sql.xml"/>
</sqlMapConfig>

六、添加映射文件

代碼：

 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sqlMap
PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"
"http://ibatis.apache.org/dtd/sql-map-2.dtd">
<sqlMap namespace="sql" >
<typeAlias
alias="upload"
type="Upload" />
<insert
id="up"
parameterClass="upload" >
INSERT INTO upload(dir,upload) values(#dir#,#uploadIn#)
</insert>
<select
id="down"
resultClass="upload" >
select dir,upload as uploadIn from upload
</select>
</sqlMap>

七、編寫數據表實體類。

注意：數據庫中的Blob類型和longblob類型在實體類中使用byte[]

代碼：

 

import java.io.FileOutputStream;

/**

* TODO Put here a description of what this class does.

*

* @author Administrator.

* Created Sep 12, 2012.

*/

public class Upload {

private String dir;

private byte[] uploadIn;

private FileOutputStream uploadOut;

/**

* TODO Put here a description of what this constructor does.

*

*/

public Upload() {

super();

// TODO Auto-generated constructor stub.

}

public String getDir() {

return this.dir;

}

public void setDir(String dir) {

this.dir = dir;

}

public byte[] getUploadIn() {

return this.uploadIn;

}

public void setUploadIn(byte[] uploadIn) {

this.uploadIn = uploadIn;

}

public FileOutputStream getUploadOut() {

return this.uploadOut;

}

public void setUploadOut(FileOutputStream uploadOut) {

this.uploadOut = uploadOut;

}

}

八、編寫連接代碼

代碼：

 

private static SqlMapClient sqlMapClient;

static {

Reader reader = null;

try {

reader = Resources.getResourceAsReader("sqlMapConfig.xml");

} catch (IOException exception) {

exception.printStackTrace();

}

// 得到SqlMapClient

sqlMapClient = SqlMapClientBuilder.buildSqlMapClient(reader);

}

九、編寫上傳文件的代碼

代碼：

 

public static void upload() {

try {

sqlMapClient.startTransaction();

Upload upload = new Upload();

upload.setDir(System.currentTimeMillis() + "");

try {

ByteArrayOutputStream bytestream = new ByteArrayOutputStream(); //轉換byte數組

FileInputStream in = new FileInputStream("d:/jcifs-1.3.14.jar"); //文件

int ch;

//轉換成byte數組

while ((ch = in.read()) != -1) {

bytestream.write(ch);

}

byte imgdata[] = bytestream.toByteArray();

upload.setUploadIn(imgdata);

} catch (IOException exception) {

exception.printStackTrace();

}

sqlMapClient.insert("up", upload);

sqlMapClient.commitTransaction();

} catch (SQLException exception) {

// TODO Auto-generated catch-block stub.

exception.printStackTrace();

}

}

十、編寫下載的文件

代碼：

 

public static void down() {

try {

byte[] Buffer = new byte[4096];

int size = 0;

sqlMapClient.startTransaction();

Upload upload = (Upload) sqlMapClient.queryForObject("down");

try {

FileOutputStream fileOutputStream = new FileOutputStream(

"d:/b.jar"); //保存文件

InputStream inputStream = new ByteArrayInputStream(

upload.getUploadIn()); //byte轉換爲流

while ((size = inputStream.read(Buffer)) != -1) {

System.out.println(size);

fileOutputStream.write(Buffer, 0, size);

}

} catch (FileNotFoundException exception) {

// TODO Auto-generated catch-block stub.

exception.printStackTrace();

} catch (IOException exception) {

// TODO Auto-generated catch-block stub.

exception.printStackTrace();

}

sqlMapClient.commitTransaction();

} catch (SQLException exception) {

// TODO Auto-generated catch-block stub.

exception.printStackTrace();

}

}