Using Regex to parse String from input

Question

Here is my code to match a String like:

    String name = qualified.replaceAll(".*\\.(?=\\w+)", "");

Where it gets from input org.myapp.TestData$RootEntity a TestData$RootEntity

However I need to be able to get just the RootEntity part of the String. Effectively getting just this.

Input Strings:

com.domain.app.RootEntity

com.domain.app.TestData$RootEntity

com.domain.app.TestData$TestNested$RootEntity

And should be able to get RootEntity

use string.lastIndexOf('$')

Braj
– Braj

2014-04-29 16:32:49 +00:00
Commented Apr 29, 2014 at 16:32 — Braj
– Braj, Commented Apr 29, 2014 at 16:32

Amit Joki · Accepted Answer · 2014-04-29 16:49:51Z

1

Try this:

String name = qualified.replaceAll(".+?\\W", "");

.*\\W matches everything before $ or . and replaces it with empty string.

edited Apr 29, 2014 at 16:49

answered Apr 29, 2014 at 16:32

Amit Joki

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2 Comments

quarks Over a year ago

For a input string "com.domain.app.RootEntity" it returns empty, it should return RootEntity

Amit Joki Over a year ago

@xybrek, glad to have helped.

Braj · Accepted Answer · 2014-04-29 17:08:17Z

1

Try with simple String#lastIndexOf()

    String qualified = "org.myapp.TestData$RootEntity";

    String name = qualified.substring(qualified.lastIndexOf('$') + 1);

Complete code

    String[] values = new String[] { "com.domain.app.RootEntity",
            "com.domain.app.TestData$RootEntity",
            "com.domain.app.TestData$TestNested$RootEntity" };

    for (String qualified : values) {
        int index = qualified.lastIndexOf('$');

        String name = null;
        if (index != -1) {
            name = qualified.substring(qualified.lastIndexOf('$') + 1);
        } else {
            name = qualified.substring(qualified.lastIndexOf('.') + 1);
        }

        System.out.println(name);
    }

output:

RootEntity
RootEntity
RootEntity

edited Apr 29, 2014 at 17:08

answered Apr 29, 2014 at 16:35

Braj

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Comments

Pedro Lobito · Accepted Answer · 2014-04-29 16:46:05Z

0

Simple:

String resultString = qualified.replaceAll("(?m).*?(RootEntity)$", "$1");

answered Apr 29, 2014 at 16:46

Pedro Lobito

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Comments

Pshemo · Accepted Answer · 2014-04-29 16:46:30Z

0

com.domain.app.RootEntity
com.domain.app.TestData$RootEntity
com.domain.app.TestData$TestNested$RootEntity

And should be able to get RootEntity

In looks like you want to remove each part of name which has . or $ after it like app. or TestData$.

If that is the case you can try

replaceAll("\\w+[.$]", "")

Demo

String[] data = {
        "com.domain.app.RootEntity",
        "com.domain.app.TestData$RootEntity",
        "com.domain.app.TestData$TestNested$RootEntity",
};
for (String s:data)
    System.out.println(s.replaceAll("\\w+[.$]", ""));

Output:

RootEntity
RootEntity
RootEntity

answered Apr 29, 2014 at 16:46

Pshemo

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