Requirements

Installation

<dependencies>  <dependency>    <groupId>com.github.javadev</groupId>    <artifactId>underscore-kotlin</artifactId>    <version>1.13</version>  </dependency>  ...</dependencies>

implementation'com.github.javadev:underscore-kotlin:1.13'

Usage

U.of(/* array | list | set | map | anything based on Iterable interface */)    .filter(..)    .map(..)    ...    .sortWith()    .forEach(..);U.of(value1,value2,value3)...U.range(0,10)...U.of(1,2,3)// or java.util.Arrays.asList(1, 2, 3) or new Integer[] {1, 2, 3}    .filter(v ->v >1)// 2, 3    .map(v ->v +1)// 3, 4    .sortWith((a,b) ->b.compareTo(a))    .forEach(System.out::println);// 4, 3U.of(1,2,3)// or java.util.Arrays.asList(1, 2, 3) or new Integer[] {1, 2, 3}    .mapMulti((num,consumer) -> {for (inti =0;i <num;i++) {consumer.accept("a" +num);        }    })    .forEach(System.out::println);// "a1", "a2", "a2", "a3", "a3", "a3"U.formatXml("<a><b>data</b></a>",Xml.XmlStringBuilder.Step.TWO_SPACES);// <a>//   <b>data</b>// </a>U.formatJson("{\"a\":{\"b\":\"data\"}}",Json.JsonStringBuilder.Step.TWO_SPACES);// {//   "a": {//     "b": "data"//   }// }U.xmlToJson("<mydocument has=\"an attribute\">\n"        +"   <and>\n"        +"   <many>elements</many>\n"        +"    <many>more elements</many>\n"        +"   </and>\n"        +"   <plus a=\"complex\">\n"        +"     element as well\n"        +"   </plus>\n"        +"</mydocument>",Json.JsonStringBuilder.Step.TWO_SPACES);// {//   "mydocument": {//     "-has": "an attribute",//     "and": {//       "many": [//         "elements",//         "more elements"//       ]//     },//     "plus": {//       "-a": "complex",//       "#text": "\n     element as well\n   "//     }//   },//   "#omit-xml-declaration": "yes"// }U.xmlToJsonMinimum("<data>\n"        +"    <string>Example Text</string>\n"        +"    <integer>42</integer>\n"        +"    <float>3.14</float>\n"        +"    <boolean>true</boolean>\n"        +"    <date>2025-02-26</date>\n"        +"    <time>14:30:00</time>\n"        +"    <datetime>2025-02-26T14:30:00Z</datetime>\n"        +"    <array>Item 1</array>\n"        +"    <array>Item 2</array>\n"        +"    <object>\n"        +"        <key1>Value 1</key1>\n"        +"        <key2>Value 2</key2>\n"        +"    </object>\n"        +"    <null/>\n"        +"</data>\n",Json.JsonStringBuilder.Step.TWO_SPACES);// {//   "data": {//     "string": "Example Text",//     "integer": "42",//     "float": "3.14",//     "boolean": "true",//     "date": "2025-02-26",//     "time": "14:30:00",//     "datetime": "2025-02-26T14:30:00Z",//     "array": [//       "Item 1",//       "Item 2"//     ],//     "object": {//       "key1": "Value 1",//       "key2": "Value 2"//     },//     "null": ""//   }// }U.jsonToXml("{\n"        +"\"mydocument\": {\n"        +"\"-has\":\"an attribute\",\n"        +"\"and\": {\n"        +"\"many\": [\n"        +"\"elements\",\n"        +"\"more elements\"\n"        +"      ]\n"        +"    },\n"        +"\"plus\": {\n"        +"\"-a\":\"complex\",\n"        +"\"#text\":\"\\n     element as well\\n\"\n"        +"    }\n"        +"  },\n"        +"\"#omit-xml-declaration\":\"yes\"\n"        +"}",Xml.XmlStringBuilder.Step.TWO_SPACES);// <mydocument has="an attribute">//   <and>//     <many>elements</many>//     <many>more elements</many>//   </and>//   <plus a="complex">//      element as well//    </plus>// </mydocument>U.jsonToXmlMinimum("{\n"        +"\"data\": {\n"        +"\"string\":\"Example Text\",\n"        +"\"integer\":\"42\",\n"        +"\"float\":\"3.14\",\n"        +"\"boolean\":\"true\",\n"        +"\"date\":\"2025-02-26\",\n"        +"\"time\":\"14:30:00\",\n"        +"\"datetime\":\"2025-02-26T14:30:00Z\",\n"        +"\"array\": [\n"        +"\"Item 1\",\n"        +"\"Item 2\"\n"        +"    ],\n"        +"\"object\": {\n"        +"\"key1\":\"Value 1\",\n"        +"\"key2\":\"Value 2\"\n"        +"    },\n"        +"\"null\":\"\"\n"        +"  }\n"        +"}",Xml.XmlStringBuilder.Step.TWO_SPACES);// <data>//   <string>Example Text</string>//   <integer>42</integer>//   <float>3.14</float>//   <boolean>true</boolean>//   <date>2025-02-26</date>//   <time>14:30:00</time>//   <datetime>2025-02-26T14:30:00Z</datetime>//   <array>Item 1</array>//   <array>Item 2</array>//   <object>//     <key1>Value 1</key1>//     <key2>Value 2</key2>//   </object>//   <null string="true"/>// </data>U.Builderbuilder =U.objectBuilder()    .add("firstName","John")    .add("lastName","Smith")    .add("age",25)    .add("address",U.arrayBuilder()        .add(U.objectBuilder()            .add("streetAddress","21 2nd Street")            .add("city","New York")            .addNull("cityId")            .add("state","NY")            .add("postalCode","10021")))    .add("phoneNumber",U.arrayBuilder()        .add(U.objectBuilder()            .add("type","home")            .add("number","212 555-1234"))        .add(U.objectBuilder()            .add("type","fax")            .add("number","646 555-4567")));System.out.println(builder.toJson());System.out.println(builder.toXml());

{"firstName":"John","lastName":"Smith","age":25,"address":[{"streetAddress":"21 2nd Street","city":"New York","cityId":null,"state":"NY","postalCode":"10021"}],"phoneNumber":[{"type":"home","number":"212 555-1234"},{"type":"fax","number":"646 555-4567"}]}

<?xml version="1.0" encoding="UTF-8"?><root>  <firstName>John</firstName>  <lastName>Smith</lastName>  <agenumber="true">25</age>  <addressarray="true">    <streetAddress>21 2nd Street</streetAddress>    <city>New York</city>    <cityIdnull="true"/>    <state>NY</state>    <postalCode>10021</postalCode>  </address>  <phoneNumber>    <type>home</type>    <number>212 555-1234</number>  </phoneNumber>  <phoneNumber>    <type>fax</type>    <number>646 555-4567</number>  </phoneNumber></root>

XmlBuilderbuilder =XmlBuilder.create("Projects")    .e("underscore-java").a("language","Java").a("scm","SVN")        .e("Location").a("type","URL")            .t("https://github.com/javadev/underscore-java/")        .up()    .up()    .e("JetS3t").a("language","Java").a("scm","CVS")        .e("Location").a("type","URL")            .t("https://jets3t.s3.amazonaws.com/index.html");System.out.println(builder.toXml(Xml.XmlStringBuilder.Step.TWO_SPACES));System.out.println(builder.toJson(Json.JsonStringBuilder.Step.TWO_SPACES));

<?xml version="1.0" encoding="UTF-8"?><Projects>    <underscore-javalanguage="Java"scm="SVN">        <Locationtype="URL">https://github.com/javadev/underscore-java/</Location>    </underscore-java>    <JetS3tlanguage="Java"scm="CVS">        <Locationtype="URL">https://jets3t.s3.amazonaws.com/index.html</Location>    </JetS3t></Projects>

{"Projects": {"underscore-java": {"-language":"Java","-scm":"SVN","Location": {"-type":"URL","#text":"https://github.com/javadev/underscore-java/"      }    },"JetS3t": {"-language":"Java","-scm":"CVS","Location": {"-type":"URL","#text":"https://jets3t.s3.amazonaws.com/index.html"      }    }  }}