Extracting substring from a String in Json Format in Java

Question

I have this string

String str= " {\"name\":\"xyz\",\"id\":\"123\" } ";

I want to extract xyz from the given string, can someone please suggest an efficient way of doing it in Java?

Answer 1

Step1 : Create Some DTO class like below

public class MyDTO{
  private String name;
  private String id;

  // Create setters and getters
}

Step2 : Convert above string to DTO(pojo class) class by using objectmapper like below

ObjectMapper objectMapper = new ObjectMapper();
String str= "{\"name\":\"xyz\",\"id\":\"123\"}";
MyDTO dto = objectMapper.readValue(str, MyDTO.class);

Step3 : After converting to DTO object you can use it with dto object like below.

System.out.println(dto.getName());

Note : If you don't have fasterxml dependency in your pom file then add the below dependency to your pom file.

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.12.3</version>
</dependency>

Happy coading..!

Answer 2

If you don't want to parse the whole JSON into an object, you can do this with JsonPath .

String str = " {\"name\":\"xyz\",\"id\":\"123\" } ";
String name = JsonPath.read(str,"$.name");
System.out.println(name);

Add the following dependency to your pom.xml

<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>2.5.0</version>
</dependency>