Use this if you want to make json files or read json text strings<\/p>\n\n\n\n
OrderSerializer<\/strong>\nid\nname\n<\/pre>\n\n\n\nProblem(s):
Want to get json out in a file
Need to read\/create object from json later<\/p>\n\n\n\nSteps:
(Add maven\/grade dependencies)
Create pojo to hold the data ie “OrderSerializer”, add jackson databind<\/p>\n\n\n\nCreate some ObjectMappers that will Map Objects to Json or Json to Objects
Caveats: I needed to add a constructor with super(); in it, not sure why.<\/p>\n\n\n\nOrderSerializerImplemeted.java<\/strong> <\/p>\n\n\n\n
OrderSerializerImplemented<\/a>Download<\/a><\/div>\n\n\n\nimport com.fasterxml.jackson.core.JsonProcessingException;\nimport com.fasterxml.jackson.databind.JsonNode;\nimport com.fasterxml.jackson.databind.ObjectMapper;\n\nimport java.io.File;\nimport java.io.IOException;\n\n\/*\nSome Jackson Object Mapper Code\nhttps:\/\/www.youtube.com\/watch?v=pv1VCFWTP-I&ab_channel=SwatechTalks\n *\/\npublic class OrderSerializerImplemented {\n public static void main(String[] args) {\n var order1 = new OrderSerializer("ID123", "Joey Mc Doughey");\n var order2 = new OrderSerializer("IDID1010", "Kevin Mc Douchy");\n\n ObjectMapper objectMapper = new ObjectMapper();\n\n try {\n \/\/ Writing files to files, same them for later.\n objectMapper.writeValue(new File("target\/order1.json"), order1);\n objectMapper.writeValue(new File("target\/order2.json"), order2);\n } catch (IOException e) {\n e.printStackTrace();\n }\n\n \/\/ load from a string literal\n try {\n ObjectMapper objectMapper1 = new ObjectMapper();\n String orderJson = "{\\"id\\":\\"ID123\\",\\"name\\":\\"Joey Mc Doughey\\"}";\n \/\/ Put the String data in objectMapper using OrderSerializer.class as the Class to use\n OrderSerializer coolOrder = objectMapper1.readValue(orderJson, OrderSerializer.class);\n System.out.println(coolOrder.getId());\n } catch (final Exception e){\n e.printStackTrace();\n } finally {\n System.out.printf("done with reading object from file");\n }\n\n \/\/ Using JsonNode to map string as an json object\n String orderJson = "{\\"id\\":\\"ID123\\",\\"name\\":\\"Blaze Mc Weedy\\"}";\n ObjectMapper objectMapper2 = new ObjectMapper();\n JsonNode jsonNode = null;\n try {\n jsonNode = objectMapper2.readTree(orderJson);\n } catch (JsonProcessingException e) {\n e.printStackTrace();\n }\n System.out.println("jsonNode.get(\\"name\\").asText() = " + jsonNode.get("name").asText());\n System.out.println("jsonNode.get(\\"id\\").asText() = " + jsonNode.get("id").asText());\n \/\/ now lets write it all out as a string through objectMapper\n ObjectMapper objectMapper3 = new ObjectMapper();\n try {\n System.out.println("Here's the whole Json String or an error: ");\n System.out.println(objectMapper3.writeValueAsString(jsonNode));\n System.out.println("Here's the same data, just nicer to look at.");\n System.out.println(jsonNode.toPrettyString());\n } catch (JsonProcessingException e) {\n e.printStackTrace();\n }\n }\n}\n\n\n<\/pre><\/div>\n\n\nHere’s the console output:<\/strong><\/p>\n\n\n
\nID123\ndone with reading object from filejsonNode.get("name").asText() = Blaze Mc Weedy\njsonNode.get("id").asText() = ID123\nHere's the whole Json String or an error: \n{"id":"ID123","name":"Blaze Mc Weedy"}\nHere's the same data, just nicer to look at.\n{\n "id" : "ID123",\n "name" : "Blaze Mc Weedy"\n}\n\nProcess finished with exit code 0\n<\/pre><\/div>\n\n\n