All Downloads are FREE. Search and download functionalities are using the official Maven repository.

spinjar.com.fasterxml.jackson.databind.PropertyNamingStrategies Maven / Gradle / Ivy

There is a newer version: 7.22.0-alpha5
Show newest version
package com.fasterxml.jackson.databind;

import com.fasterxml.jackson.databind.cfg.MapperConfig;
import com.fasterxml.jackson.databind.introspect.AnnotatedField;
import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
import com.fasterxml.jackson.databind.introspect.AnnotatedParameter;

/**
 * Container for standard {@link PropertyNamingStrategy} implementations
 * and singleton instances.
 *

* Added in Jackson 2.12 to resolve issue * databind#2715. * * @since 2.12 */ public abstract class PropertyNamingStrategies implements java.io.Serializable { private static final long serialVersionUID = 2L; /* /********************************************************************** /* Static instances that may be referenced /********************************************************************** */ /** * Naming convention used in Java, where words other than first are capitalized * and no separator is used between words. Since this is the native Java naming convention, * naming strategy will not do any transformation between names in data (JSON) and * POJOS. *

* Example external property names would be "numberValue", "namingStrategy", "theDefiniteProof". */ public static final PropertyNamingStrategy LOWER_CAMEL_CASE = LowerCamelCaseStrategy.INSTANCE; /** * Naming convention used in languages like Pascal, where all words are capitalized * and no separator is used between words. * See {@link UpperCamelCaseStrategy} for details. *

* Example external property names would be "NumberValue", "NamingStrategy", "TheDefiniteProof". */ public static final PropertyNamingStrategy UPPER_CAMEL_CASE = UpperCamelCaseStrategy.INSTANCE; /** * Naming convention used in languages like C, where words are in lower-case * letters, separated by underscores. * See {@link SnakeCaseStrategy} for details. *

* Example external property names would be "number_value", "naming_strategy", "the_definite_proof". */ public static final PropertyNamingStrategy SNAKE_CASE = SnakeCaseStrategy.INSTANCE; /** * Naming convention in which the words are in upper-case letters, separated by underscores. * See {@link UpperSnakeCaseStrategy} for details. * @since 2.13 *

*/ public static final PropertyNamingStrategy UPPER_SNAKE_CASE = UpperSnakeCaseStrategy.INSTANCE; /** * Naming convention in which all words of the logical name are in lower case, and * no separator is used between words. * See {@link LowerCaseStrategy} for details. *

* Example external property names would be "numbervalue", "namingstrategy", "thedefiniteproof". */ public static final PropertyNamingStrategy LOWER_CASE = LowerCaseStrategy.INSTANCE; /** * Naming convention used in languages like Lisp, where words are in lower-case * letters, separated by hyphens. * See {@link KebabCaseStrategy} for details. *

* Example external property names would be "number-value", "naming-strategy", "the-definite-proof". */ public static final PropertyNamingStrategy KEBAB_CASE = KebabCaseStrategy.INSTANCE; /** * Naming convention widely used as configuration properties name, where words are in * lower-case letters, separated by dots. * See {@link LowerDotCaseStrategy} for details. *

* Example external property names would be "number.value", "naming.strategy", "the.definite.proof". */ public static final PropertyNamingStrategy LOWER_DOT_CASE = LowerDotCaseStrategy.INSTANCE; /* /********************************************************************** /* Public base class for simple implementations /********************************************************************** */ /** * Intermediate base class for simple implementations */ public static abstract class NamingBase extends PropertyNamingStrategy { private static final long serialVersionUID = 2L; @Override public String nameForField(MapperConfig config, AnnotatedField field, String defaultName) { return translate(defaultName); } @Override public String nameForGetterMethod(MapperConfig config, AnnotatedMethod method, String defaultName) { return translate(defaultName); } @Override public String nameForSetterMethod(MapperConfig config, AnnotatedMethod method, String defaultName) { return translate(defaultName); } @Override public String nameForConstructorParameter(MapperConfig config, AnnotatedParameter ctorParam, String defaultName) { return translate(defaultName); } public abstract String translate(String propertyName); /** * Helper method to share implementation between snake and dotted case. */ protected String translateLowerCaseWithSeparator(final String input, final char separator) { if (input == null || input.isEmpty()) { return input; } final int length = input.length(); final StringBuilder result = new StringBuilder(length + (length >> 1)); int upperCount = 0; for (int i = 0; i < length; ++i) { char ch = input.charAt(i); char lc = Character.toLowerCase(ch); if (lc == ch) { // lower-case letter means we can get new word // but need to check for multi-letter upper-case (acronym), where assumption // is that the last upper-case char is start of a new word if (upperCount > 1) { // so insert hyphen before the last character now result.insert(result.length() - 1, separator); } upperCount = 0; } else { // Otherwise starts new word, unless beginning of string if ((upperCount == 0) && (i > 0)) { result.append(separator); } ++upperCount; } result.append(lc); } return result.toString(); } } /* /********************************************************************** /* Standard implementations /********************************************************************** */ /** * A {@link PropertyNamingStrategy} that translates typical camel case Java * property names to lower case JSON element names, separated by * underscores. This implementation is somewhat lenient, in that it * provides some additional translations beyond strictly translating from * camel case only. In particular, the following translations are applied * by this PropertyNamingStrategy. * *

  • Every upper case letter in the Java property name is translated * into two characters, an underscore and the lower case equivalent of the * target character, with three exceptions. *
    1. For contiguous sequences of upper case letters, characters after * the first character are replaced only by their lower case equivalent, * and are not preceded by an underscore. *
      • This provides for reasonable translations of upper case acronyms, * e.g., "theWWW" is translated to "the_www".
    2. *
    3. An upper case character in the first position of the Java property * name is not preceded by an underscore character, and is translated only * to its lower case equivalent. *
      • For example, "Results" is translated to "results", * and not to "_results".
    4. *
    5. An upper case character in the Java property name that is already * preceded by an underscore character is translated only to its lower case * equivalent, and is not preceded by an additional underscore. *
      • For example, "user_Name" is translated to * "user_name", and not to "user__name" (with two * underscore characters).
  • *
  • If the Java property name starts with an underscore, then that * underscore is not included in the translated name, unless the Java * property name is just one character in length, i.e., it is the * underscore character. This applies only to the first character of the * Java property name.
*

* These rules result in the following additional example translations from * Java property names to JSON element names. *

  • "userName" is translated to "user_name"
  • *
  • "UserName" is translated to "user_name"
  • *
  • "USER_NAME" is translated to "user_name"
  • *
  • "user_name" is translated to "user_name" (unchanged)
  • *
  • "user" is translated to "user" (unchanged)
  • *
  • "User" is translated to "user"
  • *
  • "USER" is translated to "user"
  • *
  • "_user" is translated to "user"
  • *
  • "_User" is translated to "user"
  • *
  • "__user" is translated to "_user" * (the first of two underscores was removed)
  • *
  • "user__name" is translated to "user__name" * (unchanged, with two underscores)
*/ public static class SnakeCaseStrategy extends NamingBase { private static final long serialVersionUID = 2L; /** * @since 2.14 */ public final static PropertyNamingStrategies.SnakeCaseStrategy INSTANCE = new PropertyNamingStrategies.SnakeCaseStrategy(); @Override public String translate(String input) { if (input == null) return input; // garbage in, garbage out int length = input.length(); StringBuilder result = new StringBuilder(length * 2); int resultLength = 0; boolean wasPrevTranslated = false; for (int i = 0; i < length; i++) { char c = input.charAt(i); if (i > 0 || c != '_') // skip first starting underscore { if (Character.isUpperCase(c)) { if (!wasPrevTranslated && resultLength > 0 && result.charAt(resultLength - 1) != '_') { result.append('_'); resultLength++; } c = Character.toLowerCase(c); wasPrevTranslated = true; } else { wasPrevTranslated = false; } result.append(c); resultLength++; } } return resultLength > 0 ? result.toString() : input; } } /** * A {@link PropertyNamingStrategy} that translates an input to the equivalent upper case snake * case. The class extends {@link PropertyNamingStrategies.SnakeCaseStrategy} to retain the * snake case conversion functionality offered by the strategy. * * @since 2.13 */ public static class UpperSnakeCaseStrategy extends SnakeCaseStrategy { private static final long serialVersionUID = 2L; /** * @since 2.14 */ public final static PropertyNamingStrategies.UpperSnakeCaseStrategy INSTANCE = new PropertyNamingStrategies.UpperSnakeCaseStrategy(); @Override public String translate(String input) { String output = super.translate(input); if (output == null) { return null; } return output.toUpperCase(); } } /** * "No-operation" strategy that is equivalent to not specifying any * strategy: will simply return suggested standard bean naming as-is. */ public static class LowerCamelCaseStrategy extends NamingBase { private static final long serialVersionUID = 2L; /** * @since 2.14 */ public final static PropertyNamingStrategies.LowerCamelCaseStrategy INSTANCE = new PropertyNamingStrategies.LowerCamelCaseStrategy(); @Override public String translate(String input) { return input; } } /** * A {@link PropertyNamingStrategy} that translates typical camelCase Java * property names to PascalCase JSON element names (i.e., with a capital * first letter). In particular, the following translations are applied by * this PropertyNamingStrategy. * *
  • The first lower-case letter in the Java property name is translated * into its equivalent upper-case representation.
* * This rules result in the following example translation from * Java property names to JSON element names. *
  • "userName" is translated to "UserName"
*/ public static class UpperCamelCaseStrategy extends NamingBase { private static final long serialVersionUID = 2L; /** * @since 2.14 */ public final static PropertyNamingStrategies.UpperCamelCaseStrategy INSTANCE = new PropertyNamingStrategies.UpperCamelCaseStrategy(); /** * Converts camelCase to PascalCase * * For example, "userName" would be converted to * "UserName". * * @param input formatted as camelCase string * @return input converted to PascalCase format */ @Override public String translate(String input) { if (input == null || input.isEmpty()){ return input; // garbage in, garbage out } // Replace first lower-case letter with upper-case equivalent char c = input.charAt(0); char uc = Character.toUpperCase(c); if (c == uc) { return input; } StringBuilder sb = new StringBuilder(input); sb.setCharAt(0, uc); return sb.toString(); } } /** * Simple strategy where external name simply only uses lower-case characters, * and no separators. * Conversion from internal name like "someOtherValue" would be into external name * if "someothervalue". */ public static class LowerCaseStrategy extends NamingBase { private static final long serialVersionUID = 2L; /** * @since 2.14 */ public final static PropertyNamingStrategies.LowerCaseStrategy INSTANCE = new PropertyNamingStrategies.LowerCaseStrategy(); @Override public String translate(String input) { if (input == null || input.isEmpty()) { return input; } return input.toLowerCase(); } } /** * Naming strategy similar to {@link PropertyNamingStrategies.SnakeCaseStrategy}, * but instead of underscores * as separators, uses hyphens. Naming convention traditionally used for languages * like Lisp. */ public static class KebabCaseStrategy extends NamingBase { private static final long serialVersionUID = 2L; /** * @since 2.14 */ public final static PropertyNamingStrategies.KebabCaseStrategy INSTANCE = new PropertyNamingStrategies.KebabCaseStrategy(); @Override public String translate(String input) { return translateLowerCaseWithSeparator(input, '-'); } } /** * Naming strategy similar to {@link PropertyNamingStrategies.KebabCaseStrategy}, * but instead of hyphens * as separators, uses dots. Naming convention widely used as configuration properties name. */ public static class LowerDotCaseStrategy extends NamingBase { private static final long serialVersionUID = 2L; /** * @since 2.14 */ public final static PropertyNamingStrategies.LowerDotCaseStrategy INSTANCE = new PropertyNamingStrategies.LowerDotCaseStrategy(); @Override public String translate(String input){ return translateLowerCaseWithSeparator(input, '.'); } } }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy