org.apache.logging.log4j.util.Strings#repeat ( )源码实例Demo

@Test
public void test_writeString_formattable_excessive_string() {
    final int maxStringLength = WRITER.getMaxStringLength();
    final String excessiveString = Strings.repeat("x", maxStringLength) + 'y';
    final String expectedJson = '"' +
            excessiveString.substring(0, maxStringLength) +
            WRITER.getTruncatedStringSuffix() +
            '"';
    @SuppressWarnings("Convert2Lambda")
    final String actualJson = WRITER.use(() ->
            WRITER.writeString(new StringBuilderFormattable() {
                @Override
                public void formatTo(StringBuilder stringBuilder) {
                    stringBuilder.append(excessiveString);
                }
            }));
    Assertions.assertThat(actualJson).isEqualTo(expectedJson);
}
 

@Test
public void test_writeString_emitter_excessive_string() {
    final int maxStringLength = WRITER.getMaxStringLength();
    final String excessiveString = Strings.repeat("x", maxStringLength) + 'y';
    final String expectedJson = '"' +
            excessiveString.substring(0, maxStringLength) +
            WRITER.getTruncatedStringSuffix() +
            '"';
    final BiConsumer<StringBuilder, String> emitter = StringBuilder::append;
    final String actualJson =
            WRITER.use(() -> WRITER.writeString(emitter, excessiveString));
    Assertions.assertThat(actualJson).isEqualTo(expectedJson);
}
 

@Test
public void test_writeString_excessive_seq() {
    final CharSequence seq = Strings.repeat("x", WRITER.getMaxStringLength()) + 'y';
    final String expectedJson = "\"" +
            Strings.repeat("x", WRITER.getMaxStringLength()) +
            WRITER.getTruncatedStringSuffix() +
            '"';
    final String actualJson = WRITER.use(() -> WRITER.writeString(seq));
    Assertions.assertThat(actualJson).isEqualTo(expectedJson);
}
 

@Test
public void test_writeString_excessive_buffer() {
    final char[] buffer =
            (Strings.repeat("x", WRITER.getMaxStringLength()) + 'y')
                    .toCharArray();
    final String expectedJson = "\"" +
            Strings.repeat("x", WRITER.getMaxStringLength()) +
            WRITER.getTruncatedStringSuffix() +
            '"';
    final String actualJson = WRITER.use(() -> WRITER.writeString(buffer));
    Assertions.assertThat(actualJson).isEqualTo(expectedJson);
}
 

@Test
public void test_maxStringLength() {

    // Create the log event.
    final int maxStringLength = 30;
    final String excessiveMessageString = Strings.repeat("m", maxStringLength) + 'M';
    final SimpleMessage message = new SimpleMessage(excessiveMessageString);
    final Throwable thrown = new RuntimeException();
    final LogEvent logEvent = Log4jLogEvent
            .newBuilder()
            .setLoggerName(LOGGER_NAME)
            .setLevel(Level.INFO)
            .setMessage(message)
            .setThrown(thrown)
            .build();

    // Create the event template node with map values.
    final String messageKey = "message";
    final String excessiveKey = Strings.repeat("k", maxStringLength) + 'K';
    final String excessiveValue = Strings.repeat("v", maxStringLength) + 'V';
    final String nullValueKey = "nullValueKey";
    final String eventTemplate = writeJson(Map(
            messageKey, Map("$resolver", "message"),
            excessiveKey, excessiveValue,
            nullValueKey, Map(
                    "$resolver", "exception",
                    "field", "message")));

    // Create the layout.
    final JsonTemplateLayout layout = JsonTemplateLayout
            .newBuilder()
            .setConfiguration(CONFIGURATION)
            .setEventTemplate(eventTemplate)
            .setMaxStringLength(maxStringLength)
            .build();

    // Check serialized event.
    usingSerializedLogEventAccessor(layout, logEvent, accessor -> {
        final String truncatedStringSuffix =
                JsonTemplateLayoutDefaults.getTruncatedStringSuffix();
        final String truncatedMessageString =
                excessiveMessageString.substring(0, maxStringLength) +
                        truncatedStringSuffix;
        assertThat(accessor.getString(messageKey)).isEqualTo(truncatedMessageString);
        final String truncatedKey =
                excessiveKey.substring(0, maxStringLength) +
                        truncatedStringSuffix;
        final String truncatedValue =
                excessiveValue.substring(0, maxStringLength) +
                        truncatedStringSuffix;
        assertThat(accessor.getString(truncatedKey)).isEqualTo(truncatedValue);
        assertThat(accessor.getString(nullValueKey)).isNull();
    });

}