I am aware that you can use Java to execute the php file from a website like below:
URLConnection conn = new URL("http://localhost/file.php").openConnection();
conn.connect();
However would it be possible to make Java read the php file as a text file and how? (Possibly via the use of the BufferedReader)
Thank you.
If you mean to read the php source, then the answer is no - you cannot read php source in a typical webserver configuration. In most cases it would be very insecure to allow it - passwords and other constants are often stored in php source code.
If however, you are just meaning to read out the result of executing the php document, as a browser would do, you can use something like;
URL u = new URL("http://www.example.com/my/php/doc.php");
URLConnection c = u.openConnection();
InputStream r = c.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(r));
for(String line; (line = reader.readLine()) != null;) System.out.println(line);
To read the source of a remote php document via http, the webserver needs to be configured to not parse & execute the file, rather just serve it blindly as a plain text file.
This can be achieved in a few ways;
Uninstall php - no php engine, no code execution.
Change the file extension - apache actually just identifies files by their file extension, so changing it to .phpsource would do the trick in many instances.
Alter the apache configuration - either globally, or via .htaccess you can alter webserver configurations for a single directory. You would want to do something like php_flag engine off or RemoveHandler .php
Note that only the first, and maybe the second, method above does not open up potential security holes in your server. So use with caution.
Related
I want to set up the REST API to support file downloads via Java (The java part is not needed at the moment -- I am saying it in here so you can make your answer more specific for my problem).
How would I do that?
For example, I have this file in a folder (./java.jar), how can I stream it in such a way for it to be downloadable by a Java client?
I forgot to say that this, is for some paid-content.
My app should be able to do this
Client: Post to server with username,pass.
Rest: Respond accordingly to what user has bought (so if it has bought that file, download it)
Client: Download file and put it in x folder.
I thought of encoding a file in base64 and then posting the encoded result into the usual .json (maybe with a nice name -- useful for the java application, and with the code inside -- though I would not know how I should rebuild the file at this point). <- Is this plausible? Or is there an easier way?
Also, please do not downvote if unnecessary, although there is no code in the question, that doesn't mean I haven't researched it, it just means that I found nothing suitable for my situation.
Thanks.
What you need is a regular file streaming, using a valid URL.
Below code is an excerpt from here
import java.net.*;
import java.io.*;
public class URLReader {
public static void main(String[] args) throws Exception {
URL oracle = new URL("http://www.oracle.com/");
BufferedReader in = new BufferedReader(
new InputStreamReader(oracle.openStream()));
String inputLine;
while ((inputLine = in.readLine()) != null)
System.out.println(inputLine);
in.close();
}
}
For your needs, based on your updated comments on the above answer, you could call your REST endpoint after user logs in(with Auth and other headers/body you wish to receive) and proceed to the download.
Convert your jar/downloadable content to bytes. More on this
Java Convert File to Byte Array and visa versa
Later, in case if you dont want regular streaming as aforementioned in previous answers, you can put the byte content in the body as Base64 String. You can encode to Base64 from your byte array using something like below.
Base64.encodeToString(byte[], Base64.NO_WRAP + Base64.URL_SAFE);
Reference from here: How to send byte[] and strings to a restful webservice and retrieve this information in the web method implementation
Again, there are many ways to do this, this is one of the ways you can probably do using REST.
I have a postgres 9.2 database, which encoding is UTF-8.
I have an application(written in java) to update this database, reading .sql files and executing them in the database.
But i found a problem:
In one of those .sql files, i have the following instruction:
insert into usuario(nome)
values('Usuário Padrão');
After executing this, when i go to the table data, what was inserted was this: "Usuário Padrão"
If i execute this command directly from pgAdmin, it creates correctly.
So i don't know if it's a problem in database, or in the program that executes the scripts.
---EDIT---
Here is how i get a JDBC connection:
public static Connection getConnection() throws SQLException{
Connection connection;
String url="jdbc:postgresql://"+servidor+":"+porta+"/"+nomeBanco;
Properties props = new Properties();
props.put("user", usuario);
props.put("password", senha);
connection=DriverManager.getConnection(url,props);
connection.setAutoCommit(false);
return connection;
}
And here is the code i use to read the file, but this looks correct, because if i print the String read from the file, it shows the correct String.
public static String lerArquivo(File arquivo){
StringBuilder conteudo=new StringBuilder();
BufferedReader br = null;
try {
br=new BufferedReader(new FileReader(arquivo));
String linha;
while((linha=br.readLine())!=null){
conteudo.append(linha).append("\n");
}
} catch (IOException e) {
FrameErroBasico f=new FrameErroBasico(null, true);
f.setText("Erro ao ler arquivo.",e);
f.setVisible(true);
}finally{
try{br.close();}catch(Exception e){}
}
return conteudo.toString();
}
This is most likely the problematic line:
br=new BufferedReader(new InputStreamReader(new FileInputStream(arquivo), "UTF-8"));
(looks like my crystal ball is still working well!)
To be sure I'd need to see the code that reads the SQL file in, but (as pointed out by jtahlborn) I'd say you're reading the file with an encoding other than the encoding it really has.
PgJDBC uses Unicode on the Java side and takes care of client/server encoding differences by always communicating with the server in utf-8, letting the server do any required encoding conversions. So unless you set client_encoding via your PgJDBC connection - something PgJDBC tries to detect and warn you about - the problem won't be on the PostgreSQL/PgJDBC side, it'll be with misreading the file.
Specifically, it looks like the file is utf-8 encoded, but you are reading it in as if it was latin-1 (ISO-8859-1) encoded. Witness this simple demo in Python to replicate the results you are getting by converting a native Unicode string to utf-8 then decoding it as if it was latin-1:
>>> print u'Usuário Padrão'.encode("utf-8").decode("latin-1");
Usuário Padrão
Your application most likely reads the file into a String in a manner that performs inappropriate text encoding conversions from the file encoding to the unicode text that Java works with internally. There is no reliable way to "auto-detect" the encoding of a file, so you must specify the text encoding of the input when reading a file. Java typically defaults to the system encoding, but that can be overridden. If you know the encoding of the file, you should explicitly pass it when opening the file for reading
You haven't shown the code that reads the file so it's hard to be more specific, but this is really a Java side issue not PostgreSQL-side. If you System.out.println your SQL file from Java you'll see that it already mangled in your Java string before you send it to the database server.
As jtahlborn said, the right way to read the file is like this:
br=new BufferedReader(new InputStreamReader(new FileInputStream(arquivo),"UTF-8"));
That was my problem, doing like this, it works like a charm.
I need to provide a feature where user can download reports in excel/csv format in my web application. Once i made a module in web application which creates excel and then read it and sent to browser. It was working correctly. This time i don't want to generate excel file, as i don't have that level of control over file systems. I guess one way is to generate appropriate code in StringBuffer and set correct contenttype(I am not sure about this approach). Other team also has this feature but they are struggling when data is very large. What is the best way to provide this feature considering size of data could be very huge. Is it possible to send data in chunk without client noticing(except delay in downloading).
One issue i forgot to add is when there is very large data, it also creates problem in server side (cpu utilization and memory consumption). Is it possible that i read fixed amount of records like 500, send it to client, then read another 500 till completed.
You can also generate HTML instead of CSV and still set the content type to Excel. This is nice for colouring and styled text.
You can also use gzip compression when the client accepts that compression. Normally there are standard means, like a servlet filter.
Never a StringBuffer or the better StringBuilder. Better streaming it out. If you do not (cannot) call setContentength, the output goes chunked (without predictive progress).
URL url = new URL("http://localhost:8080/Works/images/address.csv");
response.setHeader("Content-Type", "text/csv");
response.setHeader("Content-disposition", "attachment;filename=myFile.csv");
URLConnection connection = url.openConnection();
InputStream stream = connection.getInputStream();
BufferedOutputStream outs = new BufferedOutputStream(response.getOutputStream());
int len;
byte[] buf = new byte[1024];
while ((len = stream.read(buf)) > 0) {
outs.write(buf, 0, len);
}
outs.close();
I want to parse an XML file from URL using JDOM. But when trying this:
SAXBuilder builder = new SAXBuilder();
builder.build(aUrl);
I get this exception:
Invalid byte 1 of 1-byte UTF-8 sequence.
I thought this might be the BOM issue. So I checked the source and saw the BOM in the beginning of the file. I tried reading from URL using aUrl.openStream() and removing the BOM with Commons IO BOMInputStream. But to my surprise it didn't detect any BOM.
I tried reading from the stream and writing to a local file and parse the local file. I set all the encodings for InputStreamReader and OutputStreamWriter to UTF8 but when I opened the file it had crazy characters.
I thought the problem is with the source URL encoding. But when I open the URL in browser and save the XML in a file and read that file through the process I described above, everything works fine.
I appreciate any help on the possible cause of this issue.
That HTTP server is sending the content in GZIPped form (Content-Encoding: gzip; see http://en.wikipedia.org/wiki/HTTP_compression if you don't know what that means), so you need to wrap aUrl.openStream() in a GZIPInputStream that will decompress it for you. For example:
builder.build(new GZIPInputStream(aUrl.openStream()));
Edited to add, based on the follow-up comment: If you don't know in advance whether the URL will be GZIPped, you can write something like this:
private InputStream openStream(final URL url) throws IOException
{
final URLConnection cxn = url.openConnection();
final String contentEncoding = cxn.getContentEncoding();
if(contentEncoding == null)
return cxn.getInputStream();
else if(contentEncoding.equalsIgnoreCase("gzip")
|| contentEncoding.equalsIgnoreCase("x-gzip"))
return new GZIPInputStream(cxn.getInputStream());
else
throw new IOException("Unexpected content-encoding: " + contentEncoding);
}
(warning: not tested) and then use:
builder.build(openStream(aUrl.openStream()));
. This is basically equivalent to the above — aUrl.openStream() is explicitly documented to be a shorthand for aUrl.openConnection().getInputStream() — except that it examines the Content-Encoding header before deciding whether to wrap the stream in a GZIPInputStream.
See the documentation for java.net.URLConnection.
You might find you can avoid handling encoded responses by sending a blank Accept-Encoding header. See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html: "If no Accept-Encoding field is present in a request, the server MAY assume that the client will accept any content coding.". That seems to be occurring here.
Scenario: A website I use to research stock data has a link on the page to Export Data to Spreadsheet. The URL displayed when hovering over the export link is of the form http://www.stocksite.com/historical/export.php?symbol=C .
Question: Rather, that manually visiting the page for each stock I would like to automate the task. From Java, how can I programmatically call the site with a stock symbol and save the exported csv file? The URL and URLConnection class seem like the obvious place to start, but I'm unsure where to go from there.
All you need to do is to get the CSV in flavor of an InputStream.
InputStream input = new URL("http://example.com/file.csv").openStream();
Then you can feed it to any decent Java CSV parser API. Almost any of them take input in flavor of InputStream or Reader. If necessary, you can easily decorate InputStream as a Reader using InputStreamReader which you can then feed to the CSV parser.
Reader reader = new InputStreamReader(input, "UTF-8");