JavaWeb文件上传流程

CREATE TABLE `t_user_info` (
`noid` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(32) COLLATE utf8mb4_unicode_ci NOT NULL,
`password` varchar(32) COLLATE utf8mb4_unicode_ci NOT NULL,
`head_portrait_path` varchar(64) COLLATE utf8mb4_unicode_ci NOT NULL,
PRIMARY KEY (`noid`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

public class BaseServlet extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.获取浏览器请求的资源
String uri = req.getRequestURI();
//2.获取请求的方法名，最后斜线后面的内容
String methodName = uri.substring(uri.lastIndexOf("/")+1);
try {
//3.根据方法名获取方法，通过反射获取
Method method = this.getClass().getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
//4.调用方法
method.invoke(this, req, resp);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1/db_blog?useSSL=true
username=root
password=111111

public class BaseDao {
//采用单例模式实现，防止数据库连接超时
private static DataSource ds = null;
public QueryRunner initQueryRunner() throws Exception {
if (ds == null) {
String dbFile = this.getClass().getClassLoader().getResource("/").getFile();
dbFile = dbFile.substring(1) + "db.properties";
FileReader fr = new FileReader(dbFile);
Properties pro = new Properties();
pro.load(fr);
ds = DruidDataSourceFactory.createDataSource(pro);
}
QueryRunner qur = new QueryRunner(ds);
return qur;
}
}

@WebServlet("/user/*")
public class UserServlet extends BaseServlet{

//业务层类，用于调用业务层方法
UserService userService = new UserServiceImpl();

/**
* 注册用户
* @param req
* @param resp
*/
public void register(HttpServletRequest req, HttpServletResponse resp) {
//获取数据
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload fileUpload = new ServletFileUpload(factory);
try {
List<FileItem> fileItemList = fileUpload.parseRequest(req);
//获取当前项目的路径
String classesPath = this.getClass().getResource("/").getPath();

File f1 = new File(classesPath);
//项目路径
String projectPath = f1.getParentFile().getParentFile().getParentFile().getAbsolutePath();

//最后上传的路径
String uploadPath = projectPath + "\\ROOT\\upload\\";

File f2 = new File(uploadPath);
if (!f2.exists()) {
f2.mkdirs();
}
//存入数据库的路径
String headPortraitPath = "";
for (FileItem fileItem : fileItemList) {
if (!fileItem.isFormField()) {
//是文件域
String fileName = fileItem.getName();
//获取原来文件的后缀
String suffix = fileName.substring(fileName.lastIndexOf("."));
//生成新的文件名，为防止重复，采用随机数
String destFileName = UUID.randomUUID().toString().replace("-", "");

//存入数据库的路径拼接完毕，例如格式：随机文件名.txt
headPortraitPath = destFileName + suffix;
//写入硬盘的路径
uploadPath += headPortraitPath;
//获取输入流
InputStream is = fileItem.getInputStream();
//输出流
FileOutputStream fos = new FileOutputStream(uploadPath);
//将上传的文件写入指定路径
try {
byte[] buf = new byte[10240];
while (true) {
int realLen = is.read(buf, 0, buf.length);
if (realLen < 0) {
break;
}
fos.write(buf, 0, realLen);
}
} finally {
if (fos != null)
fos.close();
if (is != null)
is.close();
}
} else {
//不是文件域，是普通控件
//获取输入框的名称
String fieldName = fileItem.getFieldName();
//获取输入框中的值
String fieldVal = fileItem.getString("utf-8");
//加入请求域中
req.setAttribute(fieldName, fieldVal);
}
}
String username = (String) req.getAttribute("username");
String password = (String) req.getAttribute("password");
//验证参数是否合法，不为空
boolean flag = userService.exam(username, password);
if (flag) {
//将数据存入数据库
User user = new User();
user.setUsername(username);
user.setPassword(password);
user.setHead_portrait_path(headPortraitPath);
if (userService.save(user)) {
resp.sendRedirect(req.getContextPath()+"/login.jsp");
}
} else {
resp.sendRedirect(req.getContextPath()+"/register.jsp");
}
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}

/**
* 用户登录
* @param req
* @param resp
*/
public void login(HttpServletRequest req, HttpServletResponse resp) {
//获取数据
String username = req.getParameter("username");
String password = req.getParameter("password");
//验证是否存在该用户
User user = new User();
try {
if (userService.exam(username, password)) {
user.setUsername(username);
user.setPassword(password);
user = userService.getByUser(user);
if (user.getHead_portrait_path() != null) {
HttpSession s1 = req.getSession();
s1.setAttribute("user", user);
resp.sendRedirect(req.getContextPath()+"/index.jsp");
} else {
resp.sendRedirect(req.getContextPath()+"/login.jsp");
}
} else {
resp.sendRedirect(req.getContextPath()+"/login.jsp");
}
} catch(Exception e) {
e.printStackTrace();
}
}
}