[Android] Http Network

Http Network

설명

• 인터넷 사용시 퍼미션 지정 필요

코드

manifests/AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />

MainActivity

class MainActivity : AppCompatActivity() {
    private var textView: TextView? = null
    private var button: Button? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        textView = findViewById(R.id.textView)
        button = findViewById(R.id.button)

        button?.setOnClickListener {
            NetworkThread().start()
        }
    }

    inner class NetworkThread : Thread() {
        override fun run() {
            val site = "http://www.google.com"
            val url = URL(site)
            val connection = url.openConnection()

            val input = connection.getInputStream()
            val isr = InputStreamReader(input, "UTF_8")
            val br = BufferedReader(isr)
            val text = StringBuilder()

            while (true) {
                val line = br.readLine()
                if (line == null) {
                    break
                } else {
                    text.append(line)
                }
            }

            runOnUiThread {
                textView?.text = text.toString()
            }
        }
    }
}

참고

• https://youtu.be/XNRpO0BTUNw

XML Handling

코드

MainActivity

class MainActivity : AppCompatActivity() {
    private var textView: TextView? = null
    private var button: Button? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        textView = findViewById(R.id.textView)
        button = findViewById(R.id.button)

        button?.setOnClickListener {
            val xml = """
            <data>
                <item>
                    <name>john</name>
                    <age>23</age>
                    <weight>56.6</weight>
                </item>
                <item>
                    <name>tom</name>
                    <age>26</age>
                    <weight>66.6</weight>
                </item>
            </data>
            """.trimIndent()

            val factory = DocumentBuilderFactory.newInstance()
            val builder = factory.newDocumentBuilder()
            val doc = builder.parse(InputSource(StringReader(xml)))
            val root = doc.documentElement
            val itemNodeList = root.getElementsByTagName("item")

            textView?.text = ""

            for (i in 0 until itemNodeList.length) {
                val itemNode = itemNodeList.item(i) as Element
                val nameNode = itemNode.getElementsByTagName("name").item(0) as Element
                val ageNode = itemNode.getElementsByTagName("age").item(0) as Element
                val weightNode = itemNode.getElementsByTagName("weight").item(0) as Element

                textView?.append("name : ${nameNode.textContent}\n")
                textView?.append("age : ${ageNode.textContent}\n")
                textView?.append("weight : ${weightNode.textContent}\n\n")
            }
        }
    }
}

참고

• https://youtu.be/W3UKAWRr3rs

Json Handling

코드

MainActivity

class MainActivity : AppCompatActivity() {
    private var textView: TextView? = null
    private var button: Button? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        textView = findViewById(R.id.textView)
        button = findViewById(R.id.button)

        button?.setOnClickListener {
            val json = """
            [
                {
                    "name": "john",
                    "age": 23,
                    "weight": 56.6
                },
                {
                    "name": "tom",
                    "age": 26,
                    "weight": 66.6
                }
            ]
            """.trimIndent()

            val root = JSONArray(json)

            textView?.text = ""

            for (i in 0 until root.length()) {
                val obj = root.getJSONObject(i)
                val name = obj.getString("name")
                val age = obj.getString("age")
                val weight = obj.getString("weight")

                textView?.append("name : ${name}\n")
                textView?.append("age : ${age}\n")
                textView?.append("weight : ${weight}\n\n")
            }
        }
    }
}

참고

• https://youtu.be/ZQraj15FkzM