### Java Toolchain

The Gradle build uses [Java Toolchain](https://docs.gradle.org/current/userguide/toolchains.html) support to compile and execute tests across multiple versions of Java.

Available JDKs on your machine are automatically detected and wired for the various compile and test tasks.
Some tests require multiple JDKs to be installed on your computer, be aware of this if you make changes related to anything toolchains related.

    private static final String PDF_DATE = "pdf_date";

    /** Regular expression pattern for matching email addresses */
    private static final Pattern EMAIL_ADDRESS_PATTERN =
            Pattern.compile("[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,6}", Pattern.CASE_INSENSITIVE);

    /**
     * Cache for storing resource file modification timestamps to enable cache busting.

    // Patterns for sensitive data - compiled once and cached
    private static final Pattern PASSWORD_PATTERN = Pattern.compile(
            "(?i)(password|passwd|pwd|secret|token|key|credential|auth)([\"']?\\s*[:=]\\s*[\"']?)([^\"',\\s]+)", Pattern.CASE_INSENSITIVE);

    private static final Pattern IP_PATTERN = Pattern.compile("\\b(?:[0-9]{1,3}\\.){3}[0-9]{1,3}\\b");

    @Test
    void testCompileResolution() throws Exception {
        MetadataGraph res;

        res = resolver.resolveConflicts(graph, ArtifactScopeEnum.compile);

        assertNotNull(res, "null graph after resolver");
        assertNotNull(res.getVertices(), "no vertices in the resulting graph after resolver");

        }

        return ":" + firstFailedProject.getArtifactId();
    }

    protected static final Pattern NEXT_LINE = Pattern.compile("\r?\n");

    protected static final Pattern LAST_ANSI_SEQUENCE = Pattern.compile("(\u001B\\[[;\\d]*[ -/]*[@-~])[^\u001B]*$");

    protected static final String ANSI_RESET = "\u001B\u005Bm";

    protected void logSummary(

        }
        final Matcher matcher = getTagPattern().matcher(input);
        final StringBuffer sb = new StringBuffer();
        final Pattern attrPattern = Pattern.compile("\\s[^ ]+=\"([^\"]*)\"");
        while (matcher.find()) {
            final String tagStr = matcher.group();
            final Matcher attrMatcher = attrPattern.matcher(tagStr);

parser and processed by godoc—but it is not compiled directly by gc.
Instead, a separate tool, cgo, processes it to produce three output
files.  The first two, 6g.go and 6c.c, are a Go source file for 6g and
a C source file for 6c; both compile as part of the named package
(gmp, in this example).  The third, gcc.c, is a C source file for gcc;
it compiles into a shared object (.so) that is dynamically linked into

    /** Separator for header-value association in text output. */
    protected String headerValueSeparator = ": ";

    /** Pattern for detecting quoted fields. */
    private static final Pattern QUOTED_FIELD_PATTERN = Pattern.compile("^\".*\"$");

    /**
     * Constructs a new CsvExtractor.
     */
    public CsvExtractor() {
        super();
    }

    @Override
    public int getWeight() {

keeping the package name the same: `okhttp3`!

There are three kinds of compatibility we’re tracking:

 * **Binary compatibility** is the ability to compile a program against OkHttp 3.x, and then to run
   it against OkHttp 4.x. We’re using the excellent [japicmp][japicmp] library via its
   [Gradle plugin][japicmp_gradle] to enforce binary compatibility.

	  }
	}
	END
  # For Cygwin/MinGW, switch paths to Windows format before running javac and java
  verbose " - Compiling Downloader.java ..."
  "$(native_path "$JAVACCMD")" "$(native_path "$javaSource")" || die "Failed to compile Downloader.java"
  verbose " - Running Downloader.java ..."
  "$(native_path "$JAVACMD")" -cp "$(native_path "$TMP_DOWNLOAD_DIR")" Downloader "$distributionUrl" "$(native_path "$targetZip")"
fi