[spring boot] Jackson 工具类

spring-boot-demo/common/src/main/java/ml/sun/common/ext/JsonExt.kt

@@ -7,6 +7,7 @@ import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.databind.SerializationFeature
 import com.fasterxml.jackson.module.kotlin.registerKotlinModule
 import ml.sun.common.util.SpringUtil
+import kotlin.reflect.KClass
 
 object JsonExt {
     private val mapper = SpringUtil.getBean(ObjectMapper::class)
@@ -26,5 +27,31 @@ object JsonExt {
 
     fun Any.toJson(): String = if (this is String) this else mapper.writeValueAsString(this)
 
+    fun String.toObj(): JsonNode = mapper.readTree(this)
+
+    fun <T : Any> String.toObj(toValueType: KClass<T>): T = mapper.readValue(this, toValueType.java)
+
+    fun <T : Any> JsonNode.asObj(toValueType: KClass<T>): T = mapper.convertValue(this, toValueType.java)
+
+    fun <E : Any> String.toList(elementType: KClass<E>): List<E> =
+        mapper.readerForListOf(elementType.java).readValue(this)
+
+    fun <E : Any> JsonNode.asList(elementType: KClass<E>): List<E> =
+        mapper.readerForListOf(elementType.java).readValue(this)
+
+    fun <E : Any> JsonNode.getList(fieldName: String, elementType: KClass<E>): List<E> =
+        this.get(fieldName).asList(elementType)
+
+    fun <V : Any> String.toMap(valueType: KClass<V>): Map<String, V> =
+        mapper.readerForMapOf(valueType.java).readValue(this)
+
+    fun <V : Any> JsonNode.asMap(valueType: KClass<V>): Map<String, V> =
+        mapper.readerForMapOf(valueType.java).readValue(this)
+
+    fun <V : Any> JsonNode.getMap(fieldName: String, valueType: KClass<V>): Map<String, V> =
+        this.get(fieldName).asMap(valueType)
+
     fun JsonNode.getText(fieldName: String): String = this.get(fieldName).asText()
+
+    fun JsonNode.getBoolean(fieldName: String): Boolean = this.get(fieldName).asBoolean()
 }

spring-boot-demo/common/src/test/java/ml/sun/common/ext/JsonExtTest.kt

@@ -0,0 +1,61 @@
+package ml.sun.common.ext
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import ml.sun.common.ext.JsonExt.asList
+import ml.sun.common.ext.JsonExt.asMap
+import ml.sun.common.ext.JsonExt.asObj
+import ml.sun.common.ext.JsonExt.getBoolean
+import ml.sun.common.ext.JsonExt.toList
+import ml.sun.common.ext.JsonExt.toMap
+import ml.sun.common.ext.JsonExt.toObj
+import ml.sun.common.util.SpringUtil
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig
+
+@SpringJUnitConfig(SpringUtil::class, ObjectMapper::class)
+class JsonExtTest {
+    @Test
+    fun obj() {
+        data class Test(val success: Boolean, val code: Int, val message: String)
+
+        val json = """{ "success": true, "code": 0, "message": "" }"""
+        val obj = json.toObj(Test::class)
+
+        assertEquals(obj.success, true)
+        assertEquals(obj.code, 0)
+        assertEquals(obj.message, "")
+
+        val node = json.toObj()
+        assertTrue(node.getBoolean("success"))
+
+        assertEquals(obj, node.asObj(Test::class))
+    }
+
+    @Test
+    fun list() {
+        val strList = """["first", "second", "third", "fourth"]""".toList(String::class)
+
+        assertEquals(strList[0], "first")
+        assertEquals(strList.size, 4)
+
+        val intList = "[0, 1, 2, 3]".toList(Int::class)
+
+        assertEquals(intList[0], 0)
+        assertEquals(intList.size, 4)
+
+        val boolList = """[true, false]""".toObj().asList(Boolean::class)
+        assertTrue(boolList[0])
+    }
+
+    @Test
+    fun map() {
+        val json = """{ "key": "value", "success": true }"""
+        val map = json.toMap(Any::class)
+
+        assertEquals(map["key"], "value")
+        assertEquals(map["success"], true)
+        assertEquals(json.toObj().asMap(Any::class), map)
+    }
+}