Use this annotation to specify that a field is a data key, optionally providing the data key name
to use.
If the data key name is not specified, the default is the Java field's name. For example:
publicclassA{// uses data key name of "dataKeyNameMatchesFieldName"@KeypublicStringdataKeyNameMatchesFieldName;// uses data key name of "some_other_name"@Key("some_other_name")privateStringdataKeyNameIsOverridden;// not a data keyprivateStringnotADataKey;}
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-13 UTC."],[],[],null,["# Annotation Type Key (2.0.0)\n\nVersion latestkeyboard_arrow_down\n\n- [2.0.0 (latest)](/java/docs/reference/google-http-client/latest/com.google.api.client.util.Key)\n- [1.47.1](/java/docs/reference/google-http-client/1.47.1/com.google.api.client.util.Key)\n- [1.46.3](/java/docs/reference/google-http-client/1.46.3/com.google.api.client.util.Key)\n- [1.45.3](/java/docs/reference/google-http-client/1.45.3/com.google.api.client.util.Key)\n- [1.44.2](/java/docs/reference/google-http-client/1.44.2/com.google.api.client.util.Key)\n- [1.43.2](/java/docs/reference/google-http-client/1.43.2/com.google.api.client.util.Key)\n- [1.42.3](/java/docs/reference/google-http-client/1.42.3/com.google.api.client.util.Key)\n- [1.41.8](/java/docs/reference/google-http-client/1.41.8/com.google.api.client.util.Key) \n\n public interface Key implements Annotation\n\nUse this annotation to specify that a field is a data key, optionally providing the data key name\nto use.\n\nIf the data key name is not specified, the default is the Java field's name. For example: \n\n\n public class A {\n\n // uses data key name of \"dataKeyNameMatchesFieldName\"\n @Key\n public String dataKeyNameMatchesFieldName;\n\n // uses data key name of \"some_other_name\"\n @Key(\"some_other_name\")\n private String dataKeyNameIsOverridden;\n\n // not a data key\n private String notADataKey;\n }\n \nImplements\n----------\n\n[Annotation](https://docs.oracle.com/javase/8/docs/api/java/lang/annotation/Annotation.html)\n\nMethods\n-------\n\n### value()\n\n public abstract String value()\n\nOverride the data key name of the field or `\"##default\"` to use the Java field's name."]]