我正在尝试将文件路径从客户端传递到服务器端，而是获取当前的工作目录。客户端代码是：
// Create a FileUpload widget.
final FileUpload upload = new FileUpload();
upload.setName("uploadFormElement");
horizontalDatesPanel.add(upload);
//Add an Export button
Button btnExport = new Button("Export Details");
btnExport.setWidth("105px");
btnExport.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
String filePath = upload.getFilename();
if (filePath.length() == 0) {
Window.alert("No File Specified!");
} else {
List<String> printLine = Arrays.asList("1st line", "2nd line");
AsyncCallback<Void> callback = new PrintSummaryHandler<Void>(PackSummaryView.this);
rpc.printToFile(filePath, printLine, callback);
}
}
});
horizontalDatesPanel.add(btnExport);
服务器端代码是：
public void printToFile(String filePath, List<String> printLine) {
Charset utf8 = StandardCharsets.UTF_8;
List<String> lines = Arrays.asList("1st line", "2nd line");
if (filePath != null) {
filePath = FilenameUtils.getName(filePath);
filePath = getServletContext().getRealPath(filePath);
System.out.println("File path = " + filePath);
try {
Files.write(Paths.get(filePath), lines, utf8);
//Files.write(Paths.get("C:\\Users\\Glyndwr\\Documents\\file5-test.txt"), lines, utf8);
} catch (IOException e) {
e.printStackTrace();
}
}
//Done
}
我选择的文件是C：\ Users \ Glyndwr \ Documents \ file5-test.txt 打印的文件路径及其创建位置为C：\ Tomcat \ webapps \ awardtracker_n \ file5-test.txt
答案 0 :(得分：0)
这不是完全你要求的是什么？
FilenameUtils.getName会丢弃仅保留文件名（file5-test.txt）的路径，如果相对于webapp的上下文请求，ServletContext#getRealPath将为您提供该文件的绝对路径路径）
BTW，作为一项安全措施，您永远无法在现代浏览器中获得真实的文件路径，它始终是C:\fakepath\：http://www.w3.org/TR/html5/forms.html#dom-input-value-filename
答案 1 :(得分：0)
答案是由同事提供的，并采取不同的方法。获取服务器端的信息，将其返回到客户端，然后将其保存到文件中。他花了2.5个小时才开始工作，所以我会和你分享解决方案。
首先在客户端创建一个按钮来检索信息：
//Write the results to a file.
//Add an Export button
Button btnExport = new Button("Export Details");
btnExport.setWidth("105px");
btnExport.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
java.sql.Date sqlStartDate = dateBoxStart.getValue() == null ? null : new java.sql.Date(dateBoxStart.getValue().getTime());
java.sql.Date sqlEndDate = dateBoxEnd.getValue() == null ? null : new java.sql.Date(dateBoxEnd.getValue().getTime());
AsyncCallback<String> callback = new PrintPackSummaryHandler<String>(PackSummaryView.this);
rpc.printPackSummary(scoutGroupId, sqlStartDate, sqlEndDate, callback);
}
});
horizontalDatesPanel.add(btnExport);
连接是：
String printPackSummary(String groupID, Date startDate, Date endDate);
在服务器端，代码是（注意：这是以逗号分隔的，因此我可以将其写入csv文件并使用MS Excel打开它）：
public String printPackSummary(String groupID, java.sql.Date startDate, java.sql.Date endDate) {
HttpServletResponse resp = getThreadLocalResponse();
List<PackSummary> list = getPackSummary(groupID, startDate, endDate);
StringBuilder fileContent = new StringBuilder();
for(PackSummary pack : list){
fileContent.append(pack.getMetric()+","+pack.getMetricTotal()+"\n");
}
return URLEncoder.encode(fileContent.toString());
}
我在这里使用SQL来填充视图。完整性是：
public List<PackSummary> getPackSummary(String groupID, java.sql.Date startDate, java.sql.Date endDate) {
List<PackSummary> packSummaryList = new ArrayList<PackSummary>();
PreparedStatement ps = null;
// Create connection/statement variables outside of try block
Connection c = null;
String selectQry = ("SELECT 'Bronze Boomerang' as metric, COUNT(at_cub_awards.ca_id) as metricCount " +
"FROM at_cub_details, at_cub_awards, at_award " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_cub_awards.cd_id " +
" AND at_cub_awards.ca_awarded_date >= ? " +
" AND at_cub_awards.ca_awarded_date <= ? " +
" AND at_cub_awards.aw_id = at_award.aw_id " +
" AND at_award.aw_award_name LIKE '%Bronze Boomerang%' " +
"GROUP BY at_award.aw_award_type " +
"UNION " +
"SELECT 'Silver Boomerang', COUNT(at_cub_awards.ca_id) " +
"FROM at_cub_details, at_cub_awards, at_award " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_cub_awards.cd_id " +
" AND at_cub_awards.ca_awarded_date >= ? " +
" AND at_cub_awards.ca_awarded_date <= ? " +
" AND at_cub_awards.aw_id = at_award.aw_id " +
" AND at_award.aw_award_name LIKE '%Silver Boomerang%' " +
"GROUP BY at_award.aw_award_type " +
"UNION " +
"SELECT 'Gold Boomerang', COUNT(at_cub_awards.ca_id) " +
"FROM at_cub_details, at_cub_awards, at_award " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_cub_awards.cd_id " +
" AND at_cub_awards.ca_awarded_date >= ? " +
" AND at_cub_awards.ca_awarded_date <= ? " +
" AND at_cub_awards.aw_id = at_award.aw_id " +
" AND at_award.aw_award_name LIKE '%Gold Boomerang%' " +
"GROUP BY at_award.aw_award_type " +
"UNION " +
"SELECT 'Grey Wolf', COUNT(at_cub_awards.ca_id) " +
"FROM at_cub_details, at_cub_awards, at_award " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_cub_awards.cd_id " +
" AND at_cub_awards.ca_awarded_date >= ? " +
" AND at_cub_awards.ca_awarded_date <= ? " +
" AND at_cub_awards.aw_id = at_award.aw_id " +
" AND at_award.aw_award_name LIKE '%Grey Wolf%' " +
"GROUP BY at_award.aw_award_type " +
"UNION " +
"SELECT 'Level 1', COUNT(at_cub_awards.ca_id) " +
"FROM at_cub_details, at_cub_awards, at_award " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_cub_awards.cd_id " +
" AND at_cub_awards.ca_awarded_date >= ? " +
" AND at_cub_awards.ca_awarded_date <= ? " +
" AND at_cub_awards.aw_id = at_award.aw_id " +
" AND at_award.aw_award_name LIKE '%Level 1%' " +
"GROUP BY at_award.aw_award_type " +
"UNION " +
"SELECT 'Level 2', COUNT(at_cub_awards.ca_id) " +
"FROM at_cub_details, at_cub_awards, at_award " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_cub_awards.cd_id " +
" AND at_cub_awards.ca_awarded_date >= ? " +
" AND at_cub_awards.ca_awarded_date <= ? " +
" AND at_cub_awards.aw_id = at_award.aw_id " +
" AND at_award.aw_award_name LIKE '%Level 2%' " +
"GROUP BY at_award.aw_award_type " +
"UNION " +
"SELECT 'Special', COUNT(at_cub_awards.ca_id) " +
"FROM at_cub_details, at_cub_awards, at_award " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_cub_awards.cd_id " +
" AND at_cub_awards.ca_awarded_date >= ? " +
" AND at_cub_awards.ca_awarded_date <= ? " +
" AND at_cub_awards.aw_id = at_award.aw_id " +
" AND at_award.aw_award_type LIKE '%Special Interest%' " +
"GROUP BY at_award.aw_award_type " +
"UNION " +
"SELECT 'Joined', COUNT(at_cub_details.cd_id) " +
"FROM at_cub_details, at_section_details " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_section_details.cd_id " +
" AND at_section_details.sd_start_date >= ? " +
" AND at_section_details.sd_start_date <= ? " +
"GROUP BY at_cub_details.grp_id " +
"UNION " +
"SELECT 'Left', COUNT(at_cub_details.cd_id) " +
"FROM at_cub_details, at_section_details " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_id = at_section_details.cd_id " +
" AND at_section_details.sd_end_date >= ? " +
" AND at_section_details.sd_end_date <= ? " +
"GROUP BY at_cub_details.grp_id " +
"UNION " +
"SELECT 'Current', COUNT(at_cub_details.cd_id) " +
"FROM at_cub_details " +
"WHERE at_cub_details.grp_id = ? " +
" AND at_cub_details.cd_archived IS NULL " +
"GROUP BY at_cub_details.grp_id;");
try {
// Get Connection and Statement from DataSource
c = ds.getConnection();
ps = c.prepareStatement(selectQry);
try {
// Create a statement and execute the query on it
ps.setString(1, groupID);
ps.setDate(2, (java.sql.Date) startDate);
ps.setDate(3, (java.sql.Date) endDate);
ps.setString(4, groupID);
ps.setDate(5, (java.sql.Date) startDate);
ps.setDate(6, (java.sql.Date) endDate);
ps.setString(7, groupID);
ps.setDate(8, (java.sql.Date) startDate);
ps.setDate(9, (java.sql.Date) endDate);
ps.setString(10, groupID);
ps.setDate(11, (java.sql.Date) startDate);
ps.setDate(12, (java.sql.Date) endDate);
ps.setString(13, groupID);
ps.setDate(14, (java.sql.Date) startDate);
ps.setDate(15, (java.sql.Date) endDate);
ps.setString(16, groupID);
ps.setDate(17, (java.sql.Date) startDate);
ps.setDate(18, (java.sql.Date) endDate);
ps.setString(19, groupID);
ps.setDate(20, (java.sql.Date) startDate);
ps.setDate(21, (java.sql.Date) endDate);
ps.setString(22, groupID);
ps.setDate(23, (java.sql.Date) startDate);
ps.setDate(24, (java.sql.Date) endDate);
ps.setString(25, groupID);
ps.setDate(26, (java.sql.Date) startDate);
ps.setDate(27, (java.sql.Date) endDate);
ps.setString(28, groupID);
//Get result set
ResultSet result = ps.executeQuery();
while (result.next()) {
PackSummary packSummary = new PackSummary(result.getString("metric"), result.getInt("metricCount"));
packSummaryList.add(packSummary);
}
// Clean up
ps.close();
c.close();
} catch (SQLException se) {
System.out.println("SQLException in getPackSummary: " + se.toString());
} catch (Exception e) {
System.out.println("Errors occurred in getPackSummary: " + e.toString());
}
} catch (SQLException e1) {
System.out.println("SQLException in getPackSummary: " + e1.toString());
e1.printStackTrace();
} finally {
// Ensure connection is closed and returned to the pool, even if errors occur.
// This is *very* important if using a connection pool, because after all the
// connections are used, the application will hang on getConnection(), waiting
// for a connection to become available.
// Any errors from the following closes are just ignored. The main thing is
// that we have definitely closed the connection.
try { if(ps != null) ps.close(); } catch (Exception e) {}
try { if(c != null) c.close(); } catch (Exception e) {}
}
// Done
return packSummaryList;
}
返回客户端时，调用以下类，该类显示一个窗口，允许选择要保存到的路径和文件名：
class PrintPackSummaryHandler<T> implements AsyncCallback<String> {
//Get the Pack Summary details
PackSummaryView view;
public PrintPackSummaryHandler(PackSummaryView view) {
this.view = view;
}
public void onFailure(Throwable ex) {
System.out.println("RPC call failed - PackSummaryView - PrintPackSummaryHandler.");
Window.alert("Connection failed - please retry.");
}
public void onSuccess(String result) {
Window.open("data:application/csv;charset=utf-8,"+result,"_parent", "location=no") ;
System.out.println("Download succeed !!"+result);
}
}
我希望这对某人有帮助。
此致
格林