CODEWITHSUNDEEP
javafile-io
membersound
membersound

Reputation: 86687

Reading entire html file to String?

Are there better ways to read an entire html file to a single string variable than:

    String content = "";
    try {
        BufferedReader in = new BufferedReader(new FileReader("mypage.html"));
        String str;
        while ((str = in.readLine()) != null) {
            content +=str;
        }
        in.close();
    } catch (IOException e) {
    }

Upvotes: 38

Views: 144992

Answers (8)

ThmHarsh
ThmHarsh

Reputation: 601

 import org.apache.commons.io.IOUtils;
 import java.io.IOException;     
    try {
               var content = new String(IOUtils.toByteArray ( this.getClass().
                        getResource("/index.html")));
            } catch (IOException e) {
                e.printStackTrace();
            }

//Java 10 Code mentioned above - assuming index.html is available inside resources folder.

Upvotes: 0

jknair
jknair

Reputation: 4764

I prefers using Guava :

import com.google.common.base.Charsets;
import com.google.common.io.Files;
File file = new File("/path/to/file", Charsets.UTF_8);
String content = Files.toString(file);

Upvotes: 4

Pedro Lobito
Pedro Lobito

Reputation: 98881

Here's a solution to retrieve the html of a webpage using only standard java libraries:

import java.io.*;
import java.net.*;

String urlToRead = "https://google.com";
URL url; // The URL to read
HttpURLConnection conn; // The actual connection to the web page
BufferedReader rd; // Used to read results from the web page
String line; // An individual line of the web page HTML
String result = ""; // A long string containing all the HTML
try {
 url = new URL(urlToRead);
 conn = (HttpURLConnection) url.openConnection();
 conn.setRequestMethod("GET");
 rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
 while ((line = rd.readLine()) != null) {
  result += line;
 }
 rd.close();
} catch (Exception e) {
 e.printStackTrace();
}

System.out.println(result);

SRC

Upvotes: 0

Kat
Kat

Reputation: 527

As Jean mentioned, using a StringBuilder instead of += would be better. But if you're looking for something simpler, Guava, IOUtils, and Jsoup are all good options.

Example with Guava:

String content = Files.asCharSource(new File("/path/to/mypage.html"), StandardCharsets.UTF_8).read();

Example with IOUtils:

InputStream in = new URL("/path/to/mypage.html").openStream();
String content;

try {
   content = IOUtils.toString(in, StandardCharsets.UTF_8);
 } finally {
   IOUtils.closeQuietly(in);
 }

Example with Jsoup:

String content = Jsoup.parse(new File("/path/to/mypage.html"), "UTF-8").toString();

or

String content = Jsoup.parse(new File("/path/to/mypage.html"), "UTF-8").outerHtml();

NOTES:

Files.readLines() and Files.toString()

These are now deprecated as of Guava release version 22.0 (May 22, 2017). Files.asCharSource() should be used instead as seen in the example above. (version 22.0 release diffs)

IOUtils.toString(InputStream) and Charsets.UTF_8

Deprecated as of Apache Commons-IO version 2.5 (May 6, 2016). IOUtils.toString should now be passed the InputStream and the Charset as seen in the example above. Java 7's StandardCharsets should be used instead of Charsets as seen in the example above. (deprecated Charsets.UTF_8)

Upvotes: 6

Johan Sjöberg
Johan Sjöberg

Reputation: 49187

There's the IOUtils.toString(..) utility from Apache Commons.

If you're using Guava there's also Files.readLines(..) and Files.toString(..).

Upvotes: 28

SAbbasizadeh
SAbbasizadeh

Reputation: 730

You can use JSoup.
It's a very strong HTML parser for java

Upvotes: 7

user784540
user784540

Reputation:

For string operations use StringBuilder or StringBuffer classes for accumulating string data blocks. Do not use += operations for string objects. String class is immutable and you will produce a large amount of string objects upon runtime and it will affect on performance.

Use .append() method of StringBuilder/StringBuffer class instance instead.

Upvotes: 3

Jean Logeart
Jean Logeart

Reputation: 53819

You should use a StringBuilder:

StringBuilder contentBuilder = new StringBuilder();
try {
    BufferedReader in = new BufferedReader(new FileReader("mypage.html"));
    String str;
    while ((str = in.readLine()) != null) {
        contentBuilder.append(str);
    }
    in.close();
} catch (IOException e) {
}
String content = contentBuilder.toString();

Upvotes: 29

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