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jackson-utils

Jackson Project usability utilities. It's designed to add additional features like easy and centralized configuration, builder or static method set. Artifact does not include direct Jackson Project. It is up to you to add them into your project.

Features

• Encapsulate all checked exceptions from Jackson with custom runtime exception;
• A central place for configuration;
• A central place for holding ObjectMapper instances;
• Utility class to make most common operations much more comfortable to use;
• Ability to change Zone to save ZonedDateTime independently of original zone;
• ByteBuffer/InputStream support for objects, lists and maps;
• Lazy read support for list from Writer;
• Read numeric as Integer, Long, BigInteger or Double (but not only as Double);
• Advanced Reader/Writer support for enum.

Gradle

implementation 'ru.oleg-cherednik.jackson:jackson-utils:2.7'

Optional dependencies (e.g. Jackson of version 2.15.3):

implementation 'com.fasterxml.jackson.module:jackson-module-afterburner:2.15.3'
implementation 'com.fasterxml.jackson.module:jackson-module-parameter-names:2.15.3'
implementation 'com.fasterxml.jackson.datatype:jackson-datatype-jdk8:2.15.3'
implementation 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.15.3'

Maven

<dependency>
    <groupId>ru.oleg-cherednik.jackson</groupId>
    <artifactId>jackson-utils</artifactId>
    <version>2.7</version>
</dependency>

Optional dependencies (e.g. Jackson of version 2.15.3):

<dependencies>
   <dependency>
      <groupId>com.fasterxml.jackson.module</groupId>
      <artifactId>jackson-module-afterburner</artifactId>
      <version>2.15.3</version>
   </dependency>
   <dependency>
      <groupId>com.fasterxml.jackson.module</groupId>
      <artifactId>jackson-module-parameter-names</artifactId>
      <version>2.15.3</version>
   </dependency>
   <dependency>
      <groupId>com.fasterxml.jackson.datatype</groupId>
      <artifactId>jackson-datatype-jdk8</artifactId>
      <version>2.15.3</version>
   </dependency>
   <dependency>
      <groupId>com.fasterxml.jackson.datatype</groupId>
      <artifactId>jackson-datatype-jsr310</artifactId>
      <version>2.15.3</version>
   </dependency>
</dependencies>

Note: jackson-utils does not contain dependency to the specific Jackson Project version, so you have to add any version additionally

Usage

To simplify usage of jackson-utils, there're following classes:

• JacksonUtils - utility class with set of methods to use json transformation;
• EnumId - advanced enum serialization support.

JacksonUtils class

Read json from String

String to a custom object type (but not a collection)

class Data {

    int intVal;
    String strVal;

}

String json = """
              {
                  "intVal" : 666,
                  "strVal" : "omen"
              }
              """;
Data data = JacksonUtils.readValue(json, Data.class);

String to a list of custom object type

class Data {

    int intVal;
    String strVal;

}

String json = """
              [
                  {
                      "intVal" : 555,
                      "strVal" : "victory"
                  },
                  {
                      "intVal" : 666,
                      "strVal" : "omen"
                  }
              ]
              """;
List<Data> res = JacksonUtils.readList(json, Data.class);

String to a map of custom object type

Map with String keys and Map or primitive types as values

String json = """
              {
                  "victory" : {
                      "intVal" : 555,
                      "strVal" : "victory"
                  },
                  "omen" : {
                      "intVal" : 666,
                      "strVal" : "omen"
                  }
              }
              """;
Map<String, Object> map = JacksonUtils.readMap(json);

Note: map values have either primitive type or Map or List.

String to a map with String keys and given type as value

class Data {

    int intVal;
    String strVal;

}

String json = """
              {
                  "victory" : {
                      "intVal" : 555,
                      "strVal" : "victory"
                  },
                  "omen" : {
                      "intVal" : 666,
                      "strVal" : "omen"
                  }
              }
              """;
Map<String, Data> map = JacksonUtils.readMap(json, Data.class);

String to a map with Integer keys and given type as value

class Data {

    int intVal;
    String strVal;

}

String json = """
              {
                  "1" : {
                      "intVal" : 555,
                      "strVal" : "victory"
                  },
                  "2" : {
                      "intVal" : 666,
                      "strVal" : "omen"
                  }
              }
              """;
Map<Integer, Data> map = JacksonUtils.readMap(json, Integer.class, Data.class);

Read json from InputStream

InputStream to a custom object type (but not a collection)

class Data {

    int intVal;
    String strVal;

}

{
  "intVal": 666,
  "strVal": "omen"
}

try(InputStream in = ...) {
    Data data = JacksonUtils.readValue(in, Data.class);
}

InputStream to a list of custom object type

Read eager

class Data {

    int intVal;
    String strVal;

}

[
  {
    "intVal": 555,
    "strVal": "victory"
  },
  {
    "intVal": 666,
    "strVal": "omen"
  }
]

try (InputStream in = ...) {
    List<Data> res = JacksonUtils.readList(in, Data.class);
}

Read lazy

class Data {

    int intVal;
    String strVal;

}

[
  {
    "intVal": 555,
    "strVal": "victory"
  },
  {
    "intVal": 666,
    "strVal": "omen"
  }
]

try(InputStream in = ...) {
    Iterator<Data> it = JacksonUtils.readListLazy(in, Data.class);

    while (it.hasNext()) {
        Data data = it.next();
    }
}

InputStream to a map of custom object type

InputStream to a map with String keys and Map or primitive types as values

{
  "victory": {
    "intVal": 555,
    "strVal": "victory"
  },
  "omen": {
    "intVal": 666,
    "strVal": "omen"
  }
}

try (InputStream in = ...) {
    Map<String, Object> map = JacksonUtils.readMap(in);
}

Note: map values have either primitive type or Map or List.

InputStream to a map with String keys and given type as value

class Data {

    int intVal;
    String strVal;

}

{
  "victory": {
    "intVal": 555,
    "strVal": "victory"
  },
  "omen": {
    "intVal": 666,
    "strVal": "omen"
  }
}

try (InputStream in = ...) {
    Map<String, Object> map = JacksonUtils.readMap(in, Data.class);
}

Map with Integer keys and given type as value

class Data {

    int intVal;
    String strVal;

}

{
  "1": {
    "intVal": 555,
    "strVal": "victory"
  },
  "2": {
    "intVal": 666,
    "strVal": "omen"
  }
}

try (InputStream in = ...) {
    Map<Integer, Data> map = JacksonUtils.readMap(in, Integer.class, Data.class);
}

Links

• Home page: https://github.com/oleg-cherednik/jackson-utils

• Maven:

  • central: https://mvnrepository.com/artifact/ru.oleg-cherednik.jackson/jackson-utils
  • download: https://repo1.maven.org/maven2/ru/oleg-cherednik/jackson/jackson-utils