Java程序以在gradle构建文件中获取版本号

Question

I am writing a small java program which will parse the Gradle build file to get the version.

Needed the java regex pattern to match the line starting with "version 'xxxxxxxxx'" in the Gradle build file. The following is the sample Gradle build content and I need to extract the "'1.0-SNAPSHOT'" version detail

group 'com.shan.sample.gradle'
version '1.0-SNAPSHOT'

apply plugin: 'java'
apply plugin: 'application'
apply plugin: 'maven'

sourceCompatibility = 1.8


mainClassName = 'com.shan.sample.gradle.SampleProgram'

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.12'
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

Answer 1

I cannot yet post comments so:

Be aware that shakhawat answer can lead to small mismatches, it will match any version '123abc' in the file so if it happens that you have

somethingversion '456xyz'
version '123abc'

it will take the first one (assuming you'd only take first found match). To counter this in some part you can add ^\\s* in the beggining of regex like this:

^\s*(version)\s*([A-Z0-9.'/-]+)

^ matches the start of line

\\s matches any whitespace character

* is greedy matching so it will continue to match all whitespace characters in this case

so you can have as much whitespaces between version and version number and between start of line and version string in case of some lost whitespaces or similiar names put before.

Also, using gradle API ( https://docs.gradle.org/current/javadoc/org/gradle/api/Project.html ) you could create gradle simple gradle plugin that can report version via

project.version

which you can apply for each project and then run it from outside.

Answer 2

I would still recommend to parse the file by line, and pick the second word of the line, where the first word is version .

However, this below implementation will serve your purpose in the regex way. The regex (version ) ([A-Z0-9.'/-]+) has two groups, first one will capture the word version and the second group will capture the version number. So, just get the version number.

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {

    public static void main(String[] args) {

        String gradleFileContent = "group 'com.shan.sample.gradle'\n" +
                "version '1.0-SNAPSHOT'\n" +
                "\n" +
                "apply plugin: 'java'\n" +
                "apply plugin: 'application'\n" +
                "apply plugin: 'maven'\n" +
                "\n" +
                "sourceCompatibility = 1.8\n" +
                "\n" +
                "\n" +
                "mainClassName = 'com.shan.sample.gradle.SampleProgram'\n" +
                "\n" +
                "dependencies {\n" +
                "    testCompile group: 'junit', name: 'junit', version: '4.12'\n" +
                "}\n";

        Pattern p = Pattern.compile("(version )([A-Z0-9.'/-]+)");
        Matcher m = p.matcher(gradleFileContent);

        if (m.find()) {
            System.out.println(m.group(2));
        }
    }
}