一. 文件上傳的基本方法
1. 最簡單的上傳文件
我們新建一個Action類：
public class UploadAction {
private File myFile;
public File getMyFile() {
return myFile;
}
public void setMyFile(File myFile) {
this.myFile = myFile;
}
public String upload() {
try {
FileUtils.copyFile(myFile, new File("d:/temp.jpg"));
} catch (IOException e) {
e.printStackTrace();
}
return "success";
}
}然後配置struts文件和對象的jsp文件：
<struts>
<include file="common.xml"></include>
<package name="basicstruts2" extends="common" namespace="/test">
<action name="upload" class="com.thr.struts2.action.UploadAction">
<result>/upload_success.jsp</result>
</action>
</package>
</struts><body>
<form action="/web/test/upload.action" enctype="multipart/form-data" method="post">
選擇文件：<input name="myFile" type="file"/><br />
<input type="submit" name="method:upload" value="上傳" />
</form>
</body>2. 獲取文件名
如果我們想獲取源文件相關的信息，例如文件名等，就需要這樣子修改Action文件：public class UploadAction {
private File myFile;
private String myFileFileName;
private String myFileContentType;
public File getMyFile() {
return myFile;
}
public void setMyFile(File myFile) {
this.myFile = myFile;
}
public String getMyFileFileName() {
return myFileFileName;
}
public void setMyFileFileName(String myFileFileName) {
this.myFileFileName = myFileFileName;
}
public String getMyFileContentType() {
return myFileContentType;
}
public void setMyFileContentType(String myFileContentType) {
this.myFileContentType = myFileContentType;
}
public String upload() {
try {
System.out.println("文件名：" + myFile.getName());
System.out.println(myFileFileName);
System.out.println(myFileContentType);
FileUtils.copyFile(myFile, new File("d:/" + myFileFileName));
} catch (IOException e) {
e.printStackTrace();
}
return "success";
}
}3. 上傳到自己的web路徑
可以使用
FileUtils.copyFile(myFile,
new File(ServletActionContext.getServletContext()
.getRealPath("/upload/" + "/" + myFileFileName)));爲了避免上傳時會遇到報錯，還可以加入下面兩個常量：
<constant name="struts.multipart.saveDir" value="D:/web/temp"></constant>
<constant name="struts.multipart.maxSize" value="80000000"></constant>二. 上傳文件至數據庫
1. 以文件轉換成字節數組格式上傳至數據庫
我們增加一個方法：
public String upload2() {
Connection conn = DB.getConnection();
String sql = "insert into t_user(id, my_file) values(?, ?)";
try {
PreparedStatement ps = conn.prepareStatement(sql);
ps.setInt(1, 12);
ps.setBytes(2, FileUtils.readFileToByteArray(myFile));
ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
DB.closeConnection(conn);
return "success";
}2. 以字節數組轉換器保存至數據庫
要直接將byte數組存至數據庫，就要寫一個轉換器：
public class FileConverter extends DefaultTypeConverter {
@Override
public Object convertValue(Object arg0, Class arg1) {
if (arg0 instanceof File[]) {
try {
byte[] bytes = FileUtils
.readFileToByteArray(((File[]) arg0)[0]);
return bytes;
} catch (IOException e) {
e.printStackTrace();
}
}
throw new RuntimeException("不是文件類型，無法轉換！");
}
}myBytes=com.thr.struts2.converter.FileConverter public String upload3() {
Connection conn = DB.getConnection();
String sql = "insert into t_user(id, my_file) values(?, ?)";
try {
PreparedStatement ps = conn.prepareStatement(sql);
ps.setInt(1, 15);
ps.setBytes(2, myBytes);
ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}
DB.closeConnection(conn);
return "success";
}三. 複雜參數傳遞和多文件上傳
1. 複雜參數傳遞
新寫一個CollectionAciton類，裏面包括了一個List和一個Map：
public class CollectionAction {
private List<Contact> contacts;
private Map<String, Contact> contactsMap;
public List<Contact> getContacts() {
return contacts;
}
public void setContacts(List<Contact> contacts) {
this.contacts = contacts;
}
public Map<String, Contact> getContactsMap() {
return contactsMap;
}
public void setContactsMap(Map<String, Contact> contactsMap) {
this.contactsMap = contactsMap;
}
public String execute() {
return "success";
}
}配置struts文件，寫一個jsp文件用來顯示上傳內容：
<form action="/web/test/collection.action" enctype="multipart/form-data" method="post">
List：<br />
Contact:<br />
qq:<input name="contacts[0].qq" />，
tel:<input name="contacts[0].tel" />，
phone:<input name="contacts[0].phone" />，<br />
Contact2:<br />
qq:<input name="contacts[1].qq" />，
tel:<input name="contacts[1].tel" />，
phone:<input name="contacts[1].phone" />，<br />
Map：<br />
Contact:<br />
qq:<input name="contactsMap['contact'].qq" />，
tel:<input name="contactsMap'contact'].tel" />，
phone:<input name="contactsMap'contact'].phone" />，<br />
Contact2:<br />
qq:<input name="contactsMap['contact2'].qq" />，
tel:<input name="contactsMap['contact2'].tel" />，
phone:<input name="contactsMap['contact2'].phone" />，<br />
<input type="submit" value="上傳" />
</form>2. 多文件上傳
想要實現多文件上傳，只需在jsp頁面中添加多個input就可以了：
<form action="/web/test/upload.action" enctype="multipart/form-data" method="post">
選擇文件1：<input name="multiFile" type="file"/><br />
選擇文件2：<input name="multiFile" type="file"/><br />
<input type="submit" name="method:multiUpload" value="上傳" />
</form> private File[] multiFile;
private String[] multiFileFileName;
private String[] multiFileContentType;四. 文件下載
我們先修改一下數據庫增加varchar類型的fileName和contentType類型。我們上傳幾個文件到數據庫。
創建一個用來下載文件的Action：
public class DownloadAction {
private InputStream stream;
private int id;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public InputStream getStream() {
InputStream inputStream = null;
Connection conn = DB.getConnection();
String sql = "select myFile, fileName, contentType from t_user where id=?";
try {
PreparedStatement ps = conn.prepareStatement(sql);
ps.setInt(1, id);
ResultSet rs = ps.executeQuery();
rs.next();
inputStream = rs.getBinaryStream("myFile");
ActionContext.getContext()
.put("fileName", rs.getString("fileName"));
ActionContext.getContext().put("contentType",
rs.getString("contentType"));
} catch (SQLException e) {
e.printStackTrace();
}
DB.closeConnection(conn);
return inputStream;
}
public String execute() {
return "success";
}
}
然後配置struts文件：
<action name="download" class="com.thr.struts2.action.DownloadAction">
<result type="stream">
<param name="contentType">%{#contentType}</param>
<param name="inputName">stream</param>
<param name="contentDisposition">attachment;filename="%{#fileName}"</param>
</result>
</action><body>
<a href="/web/test/download.action?id=16">下載id16</a><br />
<a href="/web/test/download.action?id=17">下載id17</a><br />
<a href="/web/test/download.action?id=18">下載id18</a><br />
</body>