What is escape character in Java?
Mainly escape characters are the characters which replaces existing character with new & provided character which works best without throwing any error at runtime. Also, it’s required in order for inter systems/process transmission, i.e. same char works for C++, Java, etc programming language.
In this tutorial we will go over two Escape Character Utilities.
- URLEscapeUtil
- JSONEscapeUtil
Also this tutorial will help you if you have below questions:
- Java escape characters in string
- Which characters need to be escaped on HTML
- What does escape char means in java
- Java escape characters in string
- How do I escape a String for Java?
- Escape Sequences in Java with Examples
Let’s get started:
- Create class CrunchifyEscapeCharUtility.java
- Create method crunchifyURLEscapeUtil(String s) – which returns String with escape character in provided URL
- Create method crunchifyJSONEscapeUtil(String s) – which returns String with escape character in provided JSON
- In Main() –
- we will read the JSON data from file
- provide file name is
Crunchify_Escape_Util.txt
- We use
java.net.URLEncoderto add URL escape char
In Java when we encode a String, the following rules apply:
Here is a Crunchify_Escape_Util.txt file content. Please put it into your laptop/desktop and update path location in program.
{
"founder": "App Shah",
"blogURL": "https://crunchify.com",
"twitter": "https://twitter.com/Crunchify",
"social": {
"facebook": "http://facebook.com/Crunchify",
"pinterest": "https://www.pinterest.com/Crunchify/crunchify-articles”,
"rss": "https://crunchify.com/feed/"
}
}
Here is a complete Java Example
package crunchify.com.tutorial;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.text.StringCharacterIterator;
/**
* @author Crunchify.com
* Version: 1.0
* Updated: 01.25.2016
*
*/
public class CrunchifyEscapeCharUtility {
public static void main(String[] args) {
// URL Escape Utility
String crunchifyURL = "https://crunchify.com/this is test";
crunchifyLog("Sample URL: " + crunchifyURL);
crunchifyLog("Escaped URL: " + crunchifyURLEscapeUtil(crunchifyURL));
// JSON Escape Utility
// We will read file first and then we will do escape char on that
String jsonData = "";
BufferedReader br = null;
try {
String line;
br = new BufferedReader(
new FileReader("/Users/<Username>/Documents/Crunchify_Escape_Util.txt"));
while ((line = br.readLine()) != null) {
jsonData += line + "\n";
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)
br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
// Let's print raw JSON file data
crunchifyLog("\n Sample JSON: " + jsonData.toString());
// Let's print data after escaping JSON strings
crunchifyLog("Escaped JSON: " + crunchifyJSONEscapeUtil(jsonData.toString()));
}
// Used to ensure that HTTP query strings are in proper form, by escaping special characters such as spaces.
// Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme
public static String crunchifyURLEscapeUtil(String crunchifyURL) {
String crunchifyNewURL = null;
try {
crunchifyNewURL = URLEncoder.encode(crunchifyURL, "UTF-8");
} catch (UnsupportedEncodingException ex) {
throw new RuntimeException("UTF-8 not supported", ex);
}
return crunchifyNewURL;
}
// JSON Escape Utility
public static String crunchifyJSONEscapeUtil(String crunchifyJSON) {
final StringBuilder crunchifyNewJSON = new StringBuilder();
// StringCharacterIterator class iterates over the entire String
StringCharacterIterator iterator = new StringCharacterIterator(crunchifyJSON);
char myChar = iterator.current();
// DONE = \\uffff (not a character)
while (myChar != StringCharacterIterator.DONE) {
if (myChar == '\"') {
crunchifyNewJSON.append("\\\"");
} else if (myChar == '\t') {
crunchifyNewJSON.append("\\t");
} else if (myChar == '\f') {
crunchifyNewJSON.append("\\f");
} else if (myChar == '\n') {
crunchifyNewJSON.append("\\n");
} else if (myChar == '\r') {
crunchifyNewJSON.append("\\r");
} else if (myChar == '\\') {
crunchifyNewJSON.append("\\\\");
} else if (myChar == '/') {
crunchifyNewJSON.append("\\/");
} else if (myChar == '\b') {
crunchifyNewJSON.append("\\b");
} else {
// nothing matched - just as text as it is.
crunchifyNewJSON.append(myChar);
}
myChar = iterator.next();
}
return crunchifyNewJSON.toString();
}
// Simple log utility
private static void crunchifyLog(String crunchifyData) {
System.out.println(crunchifyData);
}
}
Eclipse Console Output:
Sample URL: https://crunchify.com/this is test
Escaped URL: http%3A%2F%2Fcrunchify.com%2Fthis+is+test
Sample JSON: {
"founder": "App Shah",
"blogURL": "https://crunchify.com",
"twitter": "https://twitter.com/Crunchify",
"social": {
"facebook": "http://facebook.com/Crunchify",
"pinterest": "https://www.pinterest.com/Crunchify/crunchify-articles”,
"rss": "https://crunchify.com/feed/"
}
}
Escaped JSON: {\n "founder": "App Shah",\n \"blogURL\": \"http:\/\/crunchify.com\",\n \"twitter\": \"http:\/\/twitter.com\/Crunchify\",\n \"social\": {\n \"facebook\": \"http:\/\/facebook.com\/Crunchify\",\n \"pinterest\": \"https:\/\/www.pinterest.com\/Crunchify\/crunchify-articles”,\n \"rss\": \"http:\/\/feeds.feedburner.com\/Crunchify\"\n }\n}\n
The post Escape Character Utility for URL and JSON data – Feel free to use in your Java Project appeared first on Crunchify.
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