.assertLogMatch(Regex("""User-Agent: okhttp/.+"""))
      .assertLogEqual("--> END GET")
      .assertLogMatch(Regex("""<-- 200 OK $url \(\d+ms\)"""))
      .assertLogEqual("Content-Type: text/html; charset=0")
      .assertLogMatch(Regex("""Content-Length: \d+"""))
      .assertLogMatch(Regex(""))
      .assertLogEqual("Body with unknown charset")
      .assertLogMatch(Regex("""<-- END HTTP \(\d+ms, 25-byte body\)"""))

        System.clearProperty("config.app.module");
    }

    // Test invalid regex in custom properties
    public void test_customProperties_invalidRegex() {
        List<String> cmdList = new ArrayList<>();

        try {
            execJob.testAddFessCustomSystemProperties(cmdList, "[invalid(regex");
            fail("Should handle invalid regex");
        } catch (Exception e) {

        assertFalse(urlFilter.match("https://other.com/page.html"));
    }

    /**
     * Test adding invalid regex include pattern
     */
    public void test_addInclude_invalidRegex() {
        String sessionId = "test-session-004";
        urlFilter.init(sessionId);

        // Invalid regex pattern should be handled gracefully
        urlFilter.addInclude(".*[invalid");

Now you know that whenever you need them you can use them in **FastAPI**.

### Pydantic v1 `regex` instead of `pattern` { #pydantic-v1-regex-instead-of-pattern }

Before Pydantic version 2 and before FastAPI 0.100.0, the parameter was called `regex` instead of `pattern`, but it's now deprecated.

You could still see some code using it:

//// tab | Pydantic v1

 */
package org.codelibs.fess.mylasta.action;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.HashSet;
import java.util.Set;
import java.util.regex.Pattern;

import org.codelibs.fess.unit.UnitFessTestCase;

public class FessLabelsTest extends UnitFessTestCase {

    private FessLabels fessLabels;

    @Override
    public void setUp() throws Exception {

        if (data == null || !maskSensitiveData) {
            return data;
        }

        // Performance optimization: skip expensive regex for high-frequency logging
        if (enableHighPerformanceMode) {
            // Fast path: only check for obvious patterns without regex
            String lowerData = data.toLowerCase();

              <exclude>%regex[.*PackageSanityTests.*.class]</exclude>
              <!-- FeatureUtilTest.*ExampleDerivedInterfaceTester, com.google.common.io.*Tester, incidentally FeatureSpecificTestSuiteBuilderTest.MyAbstractTester (but we don't care either way because it's not meant to run on its own but works OK if it does)... but not NullPointerTesterTest, etc. -->
              <exclude>%regex[.*Tester.class]</exclude>

              <exclude>%regex[.*PackageSanityTests.*.class]</exclude>
              <!-- FeatureUtilTest.*ExampleDerivedInterfaceTester, com.google.common.io.*Tester, incidentally FeatureSpecificTestSuiteBuilderTest.MyAbstractTester (but we don't care either way because it's not meant to run on its own but works OK if it does)... but not NullPointerTesterTest, etc. -->
              <exclude>%regex[.*Tester.class]</exclude>

							Suffix: ".mydomain.net/data",
							Seq:    getSequences(0, 15, 0),
						},
					},
				},
				nil,
				[][]uint64{{16, 16}},
			},
			true,
		},
		// No host regex, just disks.
		{
			"http://server1/data{1...32}",
			endpointSet{
				[]ellipses.ArgPattern{
					[]ellipses.Pattern{
						{
							Prefix: "http://server1/data",
							Suffix: "",

- **Extensible Architecture**: Plugin system for custom extractors, transformers, and clients
- **Rate Limiting**: Politeness policies and interval controllers
- **URL Filtering**: Regex-based inclusion/exclusion patterns
- **Data Persistence**: Multiple backend options including OpenSearch integration

## Technology Stack

- **Java**: 21+ (requires Java 21 or higher)
- **Build System**: Maven 3.x