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("
2. 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