java知识 特殊符号转换

■情况

想把代码中的出现  “  ’等特殊符号时，在他们的前面，转换时自动加 \    最后转换成json

决定用ObjectMapper这个类，先准备一个Map，之后，map作为一个参数，调用ObjectMapper的方法，就能在转换时自动加上 \

■代码

 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;

 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;

 public class ObjectMapperDemo {

     public static void main(String args[]) throws JsonParseException, JsonMappingException, IOException {
         ObjectMapper objectMapper = new ObjectMapper();
         //Set pretty printing of json
         objectMapper.enable(SerializationFeature.INDENT_OUTPUT);

         //Define map which will be converted to JSON
         Map<String, String>mapIdPerson  = new HashMap<String, String>();
         mapIdPerson.put("id", "001");
         mapIdPerson.put("name", "James");
         mapIdPerson.put("age", "13");
         mapIdPerson.put("address", "street \"18");

         //1. Convert Map to JSON
         String mapToJson = objectMapper.writeValueAsString(mapIdPerson);
         System.out.println("1. Convert Map to JSON :");
         System.out.println(mapToJson);

         //2. JSON to Map
         //Define Custom Type reference for map type
         TypeReference<Map<String, String>> mapType = new TypeReference<Map<String,String>>() {};
         Map<String,String> jsonToMap = objectMapper.readValue(mapToJson, mapType);
         System.out.println("\n2. Convert JSON to Map :");

         // Print map output using Java 8
         // lambda expressions
         jsonToMap.forEach((k, v) ->
                             System.out.println(k + "=" + v));
     }
 }

■运行结果

 1. Convert Map to JSON :
 {
   "address" : "street \"18",
   "name" : "James",
   "id" : "001",
   "age" : "13"
 }

 2. Convert JSON to Map :
 address=street "18
 name=James
 id=001
 age=13

maven的链接如下，你可以选择自己想要的jar包版本：

https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind