The common problems and solutions of the JSON P default program in the Java library
JSON P's default issues and solutions in JSON P defaults to the program in the Java Class Library
JSON P is a class library for processing JSON data in Java, which provides a simple and effective way to analyze and operate JSON objects.However, JSON P often encounters some common problems.This article will introduce these problems and provide corresponding solutions.
Question 1: Error occurs when using JSON P parsed JSON string.
solution:
When using JSON P to analyze the JSON strings, make sure that the format of the JSON string is correct.The JSON string should use the double quotes ("") parcel key and value, and the colon (:) is separated between the key and the value.For example, a correct json string can be like this: {"name": "John", "Age": 30}.If the JSON string format is incorrect, the analysis process will be thrown abnormal.Make sure that the format of the JSON string is correct, the following code can be used to resolve the JSON string:
import javax.json.Json;
import javax.json.JsonObject;
import javax.json.JsonReader;
import java.io.StringReader;
String jsonString = "{\"name\": \"John\", \"age\": 30}";
try (JsonReader reader = Json.createReader(new StringReader(jsonString))) {
JsonObject jsonObject = reader.readObject();
// Visit the key and value of the JSON object
String name = jsonObject.getString("name");
int age = jsonObject.getInt("age");
// Print results
System.out.println("Name: " + name);
System.out.println("Age: " + age);
}
Question 2: When using JSON P to generate a JSON string, the generated string does not meet the expectations.
solution:
When generating a JSON string, make sure the type of key and value is set correctly.According to needs, you can use the following methods to convert the value to the corresponding JSON type to generate string:
-Json.createObjectBuilder (): Used to create a JSON object builder.
-DD (): Used to add key value pairs to JSON objects.
-Build (): Used to build JSON objects.
-JSONARAYBUILDER: Used to create the JSON array.
The following is a code example, demonstrating how to use JSON P to generate JSON string:
import javax.json.Json;
import javax.json.JsonArray;
import javax.json.JsonArrayBuilder;
import javax.json.JsonObject;
import javax.json.JsonObjectBuilder;
// Generate JSON string containing array
JsonArrayBuilder arrayBuilder = Json.createArrayBuilder();
arrayBuilder.add("apple");
arrayBuilder.add("banana");
arrayBuilder.add("orange");
JsonArray jsonArray = arrayBuilder.build();
// Generate JSON string containing objects
JsonObjectBuilder objectBuilder = Json.createObjectBuilder();
objectBuilder.add("name", "John");
objectBuilder.add("age", 30);
objectBuilder.add("fruits", jsonArray);
JsonObject jsonObject = objectBuilder.build();
// Generate the final json string
String jsonString = jsonObject.toString();
// Output results
System.out.println(jsonString);
Run the above code will output the following JSON string:
json
{"name":"John", "age":30, "fruits":["apple","banana","orange"]}
Through the above introduction, you should now have a better understanding of the common problems and solutions of the JSON P default program.Keep in mind the usage method and solution of JSON P, which can process and operate JSON data more easily in actual development.
