How do you escape colon (:) in Properties file?

Solution 1:

Put the properties into the Properties object and save it using a store(...) method. The method will perform any escaping required. The Java documentation says:

"... For the key, all space characters are written with a preceding \ character. For the element, leading space characters, but not embedded or trailing space characters, are written with a preceding \ character. The key and element characters #, !, =, and : are written with a preceding backslash to ensure that they are properly loaded."

You only need to manually escape characters if you are creating / writing the file by hand.

Conversely, if you want the file to contain unescaped colon characters, you are out of luck. Such a file is malformed and probably won't load properly using the Properties.load(...) methods. If you go down this route, you'll need to implement your own custom load and/or store methods.

Solution 2:

I came across the same issue. Forward slashes / also get escaped by the store() method in Properties.

I solved this issue by creating my own CustomProperties class (extending java.util.Properties) and commenting out the call to saveConvert() in the customStore0() method.

Here is my CustomProperties class:

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.Date;
import java.util.Enumeration;
import java.util.Properties;

public class CustomProperties extends Properties {
  private static final long serialVersionUID = 1L;
  @Override
  public void store(OutputStream out, String comments) throws IOException {
      customStore0(new BufferedWriter(new OutputStreamWriter(out, "8859_1")),
                   comments, true);
  }
  //Override to stop '/' or ':' chars from being replaced by not called 
  //saveConvert(key, true, escUnicode)
  private void customStore0(BufferedWriter bw, String comments, boolean escUnicode)
          throws IOException {
      bw.write("#" + new Date().toString());
      bw.newLine();
      synchronized (this) {
          for (Enumeration e = keys(); e.hasMoreElements();) {
              String key = (String) e.nextElement();
              String val = (String) get(key);
              // Commented out to stop '/' or ':' chars being replaced
              //key = saveConvert(key, true, escUnicode);
              //val = saveConvert(val, false, escUnicode);
              bw.write(key + "=" + val);
              bw.newLine();
          }
      }
      bw.flush();
  }
}