在 Java 中将字符串（带有保留字符）转换为日期

Question

I want to convert a String (with reserved characters) to Date in Java

I have a string with some reserved characters in it. I am getting it from some source. Also I get the format of it from the same source. I tried to convert that string to a date but I was unable to.

The date I get:

{ts '2021-03-24 12:52:38.933'}

The format I get:

'{ts' ''yyyy-MM-dd HH:mm:ss{.SSS}[Z]'''}'

I tried with the sample code snippet but since {} are reserved characters and also ts is an invalid character for parsing, I am unable to parse it. Please help with how I can solve this.

Obviously I can do some string manipulation and convert it to a format I want but I don't want to do that.

String dateInString = "{ts '2021-03-24 12:52:38.933'}";

SimpleDateFormat sdf = new SimpleDateFormat("{ts' ''yyyy-MM-dd HH:mm:ss{.SSS}[Z]'''}", Locale.ENGLISH);
try {
    Date date = sdf.parse(dateInString);
    System.out.println(date);
} catch (ParseException e) {
    e.printStackTrace();
}

Answer 1

You need to escape ' with another ' .

Demo:

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

public class Main {
    public static void main(String[] args) throws ParseException {
        String dateInString = "{ts '2021-03-24 12:52:38.933'}";
        SimpleDateFormat parser = new SimpleDateFormat("'{ts '''yyyy-MM-dd HH:mm:ss.SSS'''}'", Locale.ENGLISH);
        Date date = parser.parse(dateInString);
        System.out.println(date);

        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS");
        System.out.println(formatter.format(date));
    }
}

Output:

Wed Mar 24 12:52:38 GMT 2021
2021-03-24T12:52:38.933

ONLINE DEMO

Note that the java.util Date-Time API and their formatting API, SimpleDateFormat are outdated and error-prone. It is recommended to stop using them completely and switch to the modern Date-Time API ^* .

Solution using java.time , the modern Date-Time API:

import java.text.ParseException;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Locale;

public class Main {
    public static void main(String[] args) throws ParseException {
        String dateInString = "{ts '2021-03-24 12:52:38.933'}";
        DateTimeFormatter parser = DateTimeFormatter.ofPattern("'{ts '''yyyy-MM-dd HH:mm:ss.SSS'''}'", Locale.ENGLISH);
        LocalDateTime ldt = LocalDateTime.parse(dateInString, parser);
        System.out.println(ldt);
    }
}

Output:

2021-03-24T12:52:38.933

ONLINE DEMO

Learn more about the modern Date-Time API from Trail: Date Time .

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^{* For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project .}