java透过程式取得Inputstream 需要完整代码

Question

如果以游览器打开以下的网址
http://iosnetworkdemo.appspot.com/json.jsp?msg=helloWorld

会回应{"msg":"helloWorld","状 态":"成功"}，编碼为UTF8 ，请利用Java程式呼叫此网址，此將此网址回傳的結果示在Console中(IOTest.java)，程式中的 Exception處理除了MalformedURLException可以直接由方法抛出，其它的必須使用try catch处理，所有IO都必需使用try with resource 來close。

范例：透過以下程式可以取得Inputstream

import java.net.URL;
InputStream input = new URL("http://iosnetworkdemo.appspot.com/json.jsp?msg=helloWorld").openStream();

Answer 1

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;

public class IOTest {
    public static void main(String[] args) {
        try {
            URL url = new URL("http://iosnetworkdemo.appspot.com/json.jsp?msg=helloWorld");
            
            try (InputStream input = url.openStream();
                 BufferedReader reader = new BufferedReader(new InputStreamReader(input, "UTF-8"))) {
                
                String line;
                StringBuilder response = new StringBuilder();
                
                while ((line = reader.readLine()) != null) {
                    response.append(line);
                }
                
                System.out.println(response.toString());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}