Java String Capitalize capitalize(String str)

Description

Capitalize a String , changing the first letter to upper case as per Character#toUpperCase(char) .

License

Apache License

Parameter

Parameter	Description
str	the String to capitalize

Return

the capitalized String

Declaration

public static String capitalize(String str) 

Method Source Code

//package com.java2s;
/*/*  w  w w  .j  ava 2s  .c o m*/
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

public class Main {
    /**
     * Capitalize a {@code String}, changing the first letter to
     * upper case as per {@link Character#toUpperCase(char)}.
     * No other letters are changed.
     * @param str the {@code String} to capitalize
     * @return the capitalized {@code String}
     */
    public static String capitalize(String str) {
        return changeFirstCharacterCase(str, true);
    }

    private static String changeFirstCharacterCase(String str, boolean capitalize) {
        if (!hasLength(str)) {
            return str;
        }

        char baseChar = str.charAt(0);
        char updatedChar;
        if (capitalize) {
            updatedChar = Character.toUpperCase(baseChar);
        } else {
            updatedChar = Character.toLowerCase(baseChar);
        }
        if (baseChar == updatedChar) {
            return str;
        }

        char[] chars = str.toCharArray();
        chars[0] = updatedChar;
        return new String(chars, 0, chars.length);
    }

    /**
     * Check that the given {@code CharSequence} is neither {@code null} nor
     * of length 0.
     * <p>Note: this method returns {@code true} for a {@code CharSequence}
     * that purely consists of whitespace.
     * <p><pre class="code">
     * StringUtils.hasLength(null) = false
     * StringUtils.hasLength("") = false
     * StringUtils.hasLength(" ") = true
     * StringUtils.hasLength("Hello") = true
     * </pre>
     * @param str the {@code CharSequence} to check (may be {@code null})
     * @return {@code true} if the {@code CharSequence} is not {@code null} and has length
     * @see #hasText(String)
     */
    public static boolean hasLength(CharSequence str) {
        return (str != null && str.length() > 0);
    }

    /**
     * Check that the given {@code String} is neither {@code null} nor of length 0.
     * <p>Note: this method returns {@code true} for a {@code String} that
     * purely consists of whitespace.
     * @param str the {@code String} to check (may be {@code null})
     * @return {@code true} if the {@code String} is not {@code null} and has length
     * @see #hasLength(CharSequence)
     * @see #hasText(String)
     */
    public static boolean hasLength(String str) {
        return (str != null && !str.isEmpty());
    }

    /**
     * Check whether the given {@code String} is empty.
     * <p>This method accepts any Object as an argument, comparing it to
     * {@code null} and the empty String. As a consequence, this method
     * will never return {@code true} for a non-null non-String object.
     * <p>The Object signature is useful for general attribute handling code
     * that commonly deals with Strings but generally has to iterate over
     * Objects since attributes may e.g. be primitive value objects as well.
     * @param str the candidate String
     * @since 3.2.1
     */
    public static boolean isEmpty(Object str) {
        return (str == null || "".equals(str));
    }
}

Related

1. capitalize(String str)
2. capitalize(String str)
3. capitalize(String str)
4. capitalize(String str)
5. capitalize(String str)
6. capitalize(String str)
7. capitalize(String str)
8. capitalize(String str)
9. capitalize(String str)