I want to ask a question about Java. I have use the URLConnection in Java to retrieve the DataInputStream. and I want to convert the DataInputStream into a String variable in Java. What should I do? Can anyone help me. thank you.
The following is my code:
URL data = new URL("http://google.com");
URLConnection dataConnection = data.openConnection();
DataInputStream dis = new DataInputStream(dataConnection.getInputStream());
String data_string;
// convent the DataInputStream to the String
import java.net.*;
import java.io.*;
class ConnectionTest {
public static void main(String[] args) {
try {
URL google = new URL("http://www.google.com/");
URLConnection googleConnection = google.openConnection();
DataInputStream dis = new DataInputStream(googleConnection.getInputStream());
StringBuffer inputLine = new StringBuffer();
String tmp;
while ((tmp = dis.readLine()) != null) {
inputLine.append(tmp);
System.out.println(tmp);
}
//use inputLine.toString(); here it would have whole source
dis.close();
} catch (MalformedURLException me) {
System.out.println("MalformedURLException: " + me);
} catch (IOException ioe) {
System.out.println("IOException: " + ioe);
}
}
}
This is what you want.
readUTF() expects string data to be stored in a specific way (see download.oracle.com/javase/1.3/docs/api/java/io/…). This will not be the case if you try to read content from an arbitrary URL.
DataInputStream.readLine(), your solution will not work correctly if the content encoding of the URL you are accessing is anything different than plain ASCII. This is why the readLine method is deprecated. See my answer to this same question for a way to read the contents of the URL taking into account the content encoding, without resorting to any external libraries.You can use commons-io IOUtils.toString(dataConnection.getInputStream(), encoding) in order to achieve your goal.
DataInputStream is not used for what you want - i.e. you want to read the content of a website as String.
IOUtils.toString method in order to explicitly specify the encoding.
InputStreamReader. I added the encoding, a good practice indeed.InputStreamReader instead, you still need to specify the encoding when the InputStreamReader is created, otherwise you will have the same problem (the default platform encoding would be used, which may or may not match the encoding of the URL content).InputStreamReader suggestion. (Btw the downvote can be removed, I guess)If you want to read data from a generic URL (such as www.google.com), you probably don't want to use a DataInputStream at all. Instead, create a BufferedReader and read line by line with the readLine() method. Use the URLConnection.getContentType() field to find out the content's charset (you will need this in order to create your reader properly).
Example:
URL data = new URL("http://google.com");
URLConnection dataConnection = data.openConnection();
// Find out charset, default to ISO-8859-1 if unknown
String charset = "ISO-8859-1";
String contentType = dataConnection.getContentType();
if (contentType != null) {
int pos = contentType.indexOf("charset=");
if (pos != -1) {
charset = contentType.substring(pos + "charset=".length());
}
}
// Create reader and read string data
BufferedReader r = new BufferedReader(
new InputStreamReader(dataConnection.getInputStream(), charset));
String content = "";
String line;
while ((line = r.readLine()) != null) {
content += line + "\n";
}
String str = dis.toString();, but It will give you string representation of Object, I don't understand why you need this ? Or you want to read the content of google.com here ?